EVERGREEN HONG KONG INVESTMENT LTD v. THE INCORPORATED OWNERS OF TREGUNTER PROTECH PROPERTY MANAGEMENT LTD

DCCJ 2256/2018

[2021] HKDC 1111

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

CIVIL ACTION NO 2256 OF 2018

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BETWEEN

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JUDGMENT

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INTRODUCTION

1.  This is a claim by Evergreen Hong Kong Investment Limited (the “Plaintiff”) against the Incorporated Owners of Tregunter (the “1^st Defendant”) and Protech Property Management Limited (the “2^nd Defendant”), for water seepage causing damage to the Plaintiff’s property. The case was originally commenced in the Court of First Instance (under action number HCA 2503/2016), and was transferred to the District Court pursuant to the order of Master Ho dated 17 May 2018.

2.  At the trial, the Plaintiff was represented by counsel Mr Vincent Chiu (“Mr Chiu”), and the 1^st and 2^nd Defendants were represented by counsel Mr Paul Yuk Pui Lee (“Mr Lee”).

3.  The present case does not engage substantial factual disputes. In fact, by the 1^st and 2^nd Defendants’ defence, one can see that they have taken a passive approach, admitting most of the background facts but at the same time putting the plaintiff to strict proof of its essential allegations. The key battle, therefore, is between the parties’ experts.

PLANS, DESCRIPTIONS AND ABBREVIATIONS

4.  I find it both appropriate and convenient to first provide the lay out of the property concerned, and the various parts of it that are engaged in this case. The floor plans that were repeatedly used by counsel and witnesses at the trial are also appended to this judgment for the sake of clarity and to serve as visual aid (descriptions added on the plans are highlighted in yellow). Abbreviations will be used for easy reference.

5.  It is undisputed that the Plaintiff became the owner of Penthouse A on 33^rd and 34^th Floor (including portion of the roof thereover) of Tower 2 (the “Plaintiff’s Flat”) of Tregunter (the “Estate”), situated at No 14 Tregunter Path, Hong Kong. [1]

6.  The Plaintiff’s Flat, as described in the preceding paragraph, are separated into 3 floors: (1) the 33/F; (2) the 34/F; and (3) a portion of the roof (the “Plaintiff’s Roof”).

7.  Plan 1[2] shows that 33/F is divided into, from bottom to top: (1) the balcony; (2) the living room (“LR1”); (3) dining room; (4) the nook; (5) maid’s room (“MAR”); and (5) storeroom (“STOR”). [3] Inside the STOR, there is a duct chamber (“DC”), which is adjoined on the partition wall between STOR and MAR. There is an internal staircase which leads up to the 34/F.

8.  According to Plan 2[4], the 34/F is divided into, again from bottom to top; (1) a balcony; (2) master bedroom (“MB”) with master bathroom (“Bathroom 1”) and a walk-in closet (“DR”)[5] inside of it; (3) bedroom of the younger daughter (“YDB”)[6] with a bathroom inside it (“Bathroom 2”); (4) the family area (“LR2”) where there is an internal spiral staircase (“ISS”) leading up to the Plaintiff’s Roof; (5) bedroom for the elder daughter (“EDB”)[7] with an internal bathroom (“Bathroom 3”); and (6) a study room (“SR”)[8] with an internal bathroom (“Bathroom 4”).

9.  Plan 3[9] provides for the lay out of the roof immediately above the 34/F. It includes both the Plaintiff’s Roof and a portion which is used commonly for the owners of Tower 2 (“Common Roof”). To identify their respective area, one will have to rely on Plans 4 and 5.[10] Together with Plans 6 and 7 (for 34/F and 33/F respectively)[11], the arrows and numbers printed on them are the corresponding numbers of the photographs taken by the Plaintiff via its agent, as we shall see later on in this judgment.

10.  Before moving on to the next segment, one should note from Plans 3 to 5 that the ISS is shown thereon. At the top end of the ISS, there is a stair hood which not only covered it, but also include a corridor that leads to a door through which one can gain access to the Plaintiff’s Roof (“SH”). The Plaintiff asserts that the internal space of the SH forms part of the Plaintiff’s Flat.

THE PLEADED FACTS, AGREEMENTS, AND THE DISPUTES

11.  By the parties’ respective pleadings[12], including the further and better particulars provided by the Plaintiff (“F&BP”), the following matters are agreed:-

(1) The 1^st Defendant was and is the incorporated owners of the Estate since 21 April 2009.

(2) By a management agreement dated 25 January 2016, the 1^st Defendant appointed the 2^nd Defendant as the building manager of the Estate (the “Management Agreement”).

(3) The Plaintiff, together with the 1^st and 2^nd Defendants, are bound by the Management Agreement. Apart from this, they are also obliged to observe and comply with the Deed of Mutual Covenant dated 13 October 1981(the “Principal Deed”) and the Supplemental Deed of Mutual Covenant dated 16 January 1992 (the “Supplemental Deed”).

(4) The 1^st and 2^nd Defendants’ respective duties are set out in the clauses in the Principal Deed, Supplemental Deed, Management Agreement, and the Building Management Ordinance (Cap 344) (the “BMO”) as cited by the Plaintiff in its Revised Statement of Claim.

(5) Pursuant to Schedule 1 of the BMO, common parts include, inter alia:-

(a) external walls and load bearing walls, foundations, columns, beams and other structural supports; and

(b) the roofs.

(6) The water proofing membrane (i.e. the one immediately beneath the roof of Tower 2 of the Estate), the Common Roof, and the external walls of Tower 2 (the “Subject Common Parts”) form part of the Common Areas and Facilities as defined in Clause 8(1) of the Supplemental Deed and/or common parts as defined in section 2 of the BMO.

12.  Amongst the clauses cited by the Plaintiff, the ones that are crucial to the present case are as follows:-

(1) Clause 10(b)(10) of the Principal Deed provides that one of the 2^nd Defendant’s powers and duties is to use its best endeavours to keep in good repair and condition the main structural of the Estate and the roofs thereof the Common Areas and Facilities, pipes, sewers, drains, water courses, nullahs and etcetera, which are for the common use of the owners and occupants of the Estate and to replace any parts thereof where necessary.[13]

(2) Clause 19(d)(i) of the Principal Deed expresses that the owners of the penthouses of each tower within the Estate shall, subject to the Ninth Schedule, have exclusive use, possession and enjoyment of that portion of the roof above their respective penthouses exclusively assigned to them. Applying this to the present case, the portion of the roof of Tower 2 which is located above the Plaintiff’s Flat, i.e. the Plaintiff’s Roof, is assigned for the use, possession and enjoyment of the Plaintiff. Such entitlement comes with duties: Plaintiff is solely responsible for the maintenance repair and renovation of the fabric of the Plaintiff’s Roof at its own expense. The exception is where the repairs concern the structure thereof or the waterproofing membrane, which fall within the jurisdiction of the 2^nd Defendant, and the expenses for the same shall be borne by all the owners as provided under Clause 10(b)(10). However, where it can be shown that the damage to the waterproofing membrane has been occasioned by the negligence or default of the Plaintiff, the 2^nd Defendant shall be entitled to recover the costs of repairing the same from the Plaintiff.

13.  The allegations that are either denied or not admitted by the 1^st and 2^nd Defendants are set out below.

14.  The Plaintiff alleges that in 2012, the 1^st Defendant engaged CBRE Limited (“CBRE”) as consultant, which in turn instructed Hong Dau Construction Company Limited (“Hong Dau”) to carry out repair and/or renovation work of the external walls of all buildings within the Estate (the “Renovation Works”).

15.  Thereafter, and since 2013, there have been persistent water seepage problems and damage immediately above or adjacent to the Plaintiff’s Flat, including its walls and ceilings. In the F&BP, the Plaintiff expands on this and says that after their appearance in 2013, the problems had temporarily ceased in early 2016, but re-emerged in mid-2016.

16.  The Plaintiff says that since the occurrence of the problems, its director Dr Huan Guocang (“Dr Huan”) and renovation consultant Argent Consultants Company (“Argent”), had repeatedly complained to the 1^st and 2^nd Defendants but to no avail. Letters dated 31 May 2016, 15 June 2016, 9 August 2016 and 8 September 2016 issued by the Plaintiff’s solicitors[14] bore no fruit as well.

17.  Regarding the roof, there was dampness or water leakage at both the external wall and internal wall of the SH, causing the paint to peel-off.

18.  As to the 34/F, the Plaintiff alleges that there was dampness or water leakage, causing damaged structure, spalled concrete, paint to peel-off, and discolouring, at various areas of the ceilings inside the EDB. Similar problems occurred at the ceiling of the DR. DR also suffered from resultant water colour stain mark and damage to the timber flooring.

19.  The 33/F was not immune. Problems similar to those found in EDB appeared at the ceiling and wall of the STOR.

20.  For completeness sake, the Plaintiff also alleged that there were dampness, water stain mark and discolouring of the ceiling or walls of Bathroom 4 inside the SR. At the wall outside MB, the ceiling just outside the SR, and at the wall of LR2 outside MB and close to YDB, there were also dampness or water leakage. Notwithstanding these allegations, Mr Chiu confirmed in his opening statements that these areas would not be pursued by the Plaintiff, as the parties’ experts did not cover the same in their reports. These areas are therefore excluded from this judgment.

21.  The Plaintiff alleges that the aforesaid problems stemmed from the failure or refusal by the 1^st and 2^nd Defendants to discharge their duties under the Principal Deed, Supplemental Deed, Management Agreement, and the BMO, i.e. to maintain the Subject Common Parts. Moreover, it points to Hong Dau being equally culpable. In particular:-

(1) the poor workmanship by the employees and/or agents of Hong Dau in carrying out the Renovation Work in relation to parts of the external walls around or above the Plaintiff’s Flat and/or the waterproofing membrane on the roof of Tower 2;

(2) damage caused to the waterproofing membrane on parts of the roof of Tower 2;

(3) sub-standard quality of the paint used or applied by Hong Dau to the surface of the structures erected on the roof; and

(4) poor waterproofing function of the cement or sand plastering sub-strata of the external wall tiling and the poor workmanship of the grouting of such tiles around and/or above the Plaintiff’s Flat.

22.  The Plaintiff adds that, by reason of the matters set out in §§11-20 above, and in breach of the Principal Deed, Supplemental Deed, Management Agreement, and the BMO, the 1^st and 2^nd Defendants have caused nuisance or annoyance to it.

23.  Due to the inaction on the part of the 1^st and 2^nd Defendants, the Plaintiff had to instruct Argent to render urgent alleviation works to the Plaintiff’s Flat, in aim to maintain its habitable state and condition. Argent was also engaged in September 2016 to examine and investigate the problems, and water ponding tests at the Common Roof (which is above the DR and guest room[15]) was set to be conducted on 15 October 2016 (which was ultimately prevented by the 1^st and 2^nd Defendants). For these, the Plaintiff has incurred not only the costs for repairs, but the loss of enjoyment of part of the Plaintiff’s Flat starting from October 2013 up to and until the problems are resolved.

24.  In light of the above, the Plaintiff seeks: (1) mandatory injunction ordering the 1^st and 2^nd Defendants do forthwith identify the cause of the problems and take such steps to repair the external walls and/or waterproofing membrane on the Plaintiff’s Roof and/or otherwise rectify the problems; (2) damages to be assessed; (3) interest on damages; (4) costs; and (5) further or other relief.

ISSUES TO BE DECIDED

25.  By the parties’ agreed list of issues lodged on 27 August 2019, the court is tasked to resolve the following issues:-

(1) Whether the 1^st and/or 2^nd Defendant have/has failed to maintain the Subject Common Parts in a state of good and serviceable repair (“Issue 1”)?

(2) Whether the 1^st and/or 2^nd Defendants are/is in breach of the Principal Deed, Supplemental Deed, Management Agreement, and/or the BMO (“Issue 2”)?

(3) As to the water seepage problem at the Plaintiff’s Flat:-

(a) the cause of the same (“Issue 3A”);

(b) whether the water seepage caused damage to the Plaintiff’s Flat as pleaded, and if so, in which area(s) and during which period(s) (including whether the problem is continuing) (“Issue 3B”).

(4) Whether the Plaintiff has suffered loss and damage as pleaded, and if so, whether the 1^st and/or 2^nd Defendants are/is liable for such loss and damage and the amount thereof (“Issue 4”)?

(5) Whether the Plaintiff should be granted mandatory injunction against the 1^st and/or 2^nd Defendants, and if so, the scope of such mandatory injunction (“Issue 5”)?

AGREED CHRONOLOGY OF EVENTS

26.  Apart from the issues, the parties have also agreed on the following chronology of events:-

(1) The Plaintiff alleges that the water seepage problems at the Plaintiff’s Flat started in 2013.

(2) The Renovation Works were completed in mid-2014.

(3) There was some amelioration and temporary stoppage of the water leakage problems in 2015.

(4) The Plaintiff alleges that in mid-2016, the water leakage problems reappeared and became more serious.

(5) On 16 May 2016, staff of the 2^nd Defendant and Ah Tung (阿東) of Argent inspected the Plaintiff’s Flat and the roof of Tower 2 (“1^st Inspection”). They conducted another inspection on 23 May 2016 (“2^nd Inspection”).

(6) An email was issued by Dr Huan to the 2^nd Defendant on 24 May 2016, complaining about the water leakage problems at the Plaintiff’s Flat (“Huan’s Email”). Thereafter, on 25 May 2016, 30 May 2016 and 1 June 2016, Ah Tung of Argent issued emails to the 2^nd Defendant to follow up on the complaints and inquired about the proposed repairs at the roof of Tower 2 (collectively referred to as “Ah Tung’s Emails”).

(7) The 2^nd Defendant, in its email dated 12 July 2016 (“D2’s 12.7.2016 Email”), reported that its contractor had on 20 June 2016 commenced waterproofing works on the roof. Tests were then conducted on 27 and 28 June 2016, and its contractor found that there was no water leakage in the bedroom of the Plaintiff’s Flat. The waterproofing works on the roof were completed on 9 July 2016 (“Waterproofing Works”).

(8) On 5 August 2016, the 2^nd Defendant sent an email to the Plaintiff, stating amongst other things that the case had been reported to its insurer, and advised that quotations be sent to the insurer for further handling.

(9) On 6 September 2016, the 2^nd Defendant in its email to the Plaintiff acknowledged the latter’s complaint of water leakage, and promised to arrange contractors to follow up on the issues (“D2’s 6.9.2016 Email”).

(10) The writ of summons for the present action was issued on 28 September 2016.

(11) Dr Lam Siu Shu Eddie (“Dr Lam”), the expert for the Plaintiff in this case, inspected the Plaintiff’s Flat on 5 May 2017.

(12) The first joint inspection by Dr Lam, and expert for the 1^st and 2^nd Defendants Mr Mak Nai Cheong (“Mr Mak”), took place on 26 May 2017 (“1^st Joint Expert Inspection”).

(13) On 26 September 2017, the second joint inspection was conducted by Dr Lam and Mr Mak (“2^nd Joint Expert Inspection”).

(14) Between 6 and 15 November 2017, preparation for and performance of the flooding test were carried out by Dr Lam and Mr Mak (“Flooding Test”).

EVIDENCE OF DR HUAN

His evidence-in-chief

27.  Dr Huan is the only factual witness to give evidence in this case. He adopted his witness statement dated 29 August 2017 as part of his evidence-in-chief at the trial.

28.  Dr Huan’s narratives started with the occupants of the Plaintiff’s Flat, i.e. himself, his wife and their 2 daughters. He had also introduced Argent and Ah Tung at the start of his witness statement, as both played vital roles in the affairs. In fact, Ah Tung (together with Dr Huan’s secretary Ms Daisy Wong) was delegated by Dr Huan to handle the discussions with the 2^nd Defendant, and, as one can see from the sections below, Ah Tung’s views were adopted by Dr Huan in targeting the Renovation Works, Waterproofing Works and the Repair Works (as defined in §36 of this judgment) as the causes of the water leakage problems.

29.  Pausing here, Mr Chiu has assured this court that Ah Tung’s views contained in Dr Huan’s witness statement will not be taken as expert evidence. They are there just to illustrate on the steps taken by the Plaintiff to draw the 2^nd Defendant’s attention to the water leakage incidents.

30.  Back to his evidence, Dr Huan said that the water leakage problem first surfaced in 2013. Complaints lodged with the 2^nd Defendant had apparently fallen on deaf ears. As such, Dr Huan instructed Argent to perform some urgent alleviation works. He added that, at the material time, the Renovation Works were in progress, and in spite of their completion in mid-2014, the leakage problems persisted until they temporarily subsided in early 2015.

31.  According to Ah Tung, the water leakages appeared at the EDB, the STOR and the MAR. Dr Huan said that the water leakage caused the paint at their walls and ceilings to become discoloured and peeled-off. Concrete at these locations were spalled. Ah Tung remarked it was highly likely that the water came from the external walls and the Common Roof, the latter being directly above EDB. Ah Tung believed that the poor workmanship of Hong Dau in performing the Renovation Works was the cause of the water leakage.

32.  Water leakage reappeared in early 2016, and the problems deteriorated with time. Droplets of water began falling from the ceilings to the floor, causing discolouring and erosion of the floor tiles. Damage was also caused to the walls, furniture and clothes. The maid had to place buckets on the floor beneath the ceilings to catch the water.[16]

33.  After complaints were lodged with the 2^nd Defendant, staff of the same and Ah Tung conducted the 1^st and 2^nd Inspections. After the 1^st Inspection, the staff promised Ah Tung that the matter would be followed-up by Hong Dau. However, there was a change in attitude after the 2^nd Inspection. The staff gave no promise on when the matter could be resolved; only a message from Hong Dau that it would take note of the condition after raining was relayed. This led to Huan’s Email, under which Dr Huan vented out his frustration and pressed for immediate action to be taken by the 2^nd Defendant. After Huan’s Email, Ah Tung’s Emails ensued, where he requested from the 2^nd Defendant the timetable, methods and progress of the repairs. There was no reply from the 2^nd Defendant to these emails. Hence, Messrs Leung & Associates stepped in to demand for incident reports, statements from staff, and details for any repair arrangements. Nevertheless, the 2^nd Defendant remained uncommunicative.

34.  Apart from issuing the Ah Tung’s Emails, Ah Tung was also instructed by Dr Huan to inspect the water leakage problems. He reported that there were multiple water marks on the ceilings of the EDB. These water marks expanded on days when there was rainfall. As there was neither any water pipe installed inside the ceilings nor on the Common Roof directly above the EDB, he opined that the water came from the Common Roof and penetrated the waterproofing membrane underneath it.[17]

35.  By the time D2’s 12.7.2016 Email was issued, the Waterproofing Works had been completed. Not only was there no notification about the same was given by the 2^nd Defendant to Dr Huan, Ah Tung or Messrs Leung & Associates, the Waterproofing Works did not cure the water leakage problems. Instead, the situation had further deteriorated. For example, there was serious water leakage at the DR, causing disturbance to Dr Huan and his wife as users of the MB and DR. After inspection on 20 July 2016, Ah Tung maintained his previous view that the water came from the Common Roof and penetrated the waterproofing membrane underneath it.[18]

36.  Another inspection was conducted by Ah Tung on 6 September 2016 (together with Mr Li of the 2^nd Defendant and Ms Daisy Wong). He opined that the water leakage problems stemmed from the deficiencies in the repair works on the Common Roof, that were completed 2-week prior (the “Repair Works”). Ah Tung alleged that the Repair Works did not cover the entire Common Roof; he also suspected that the poor workmanship at the interface between old and new waterproofing membranes had led to the water leakage. Ah Tung added that it could not be mere coincidence that there was water leakage again on the first day it rained after completion of the Repair Works. Furthermore, as the location where repairs were performed on the Common Roof was very close to the Plaintiff’s Roof, Ah Tung commented that the vibration created by hammering during subsistence of the Repair Works could cause damage to the waterproofing membrane covering the Plaintiff’s Roof.[19]

37.  It was said that at the abovementioned inspection, Mr Li of the 2^nd Defendant acknowledged the seriousness of the leakage, admitted that the problems were caused by the faulty Repair Works, and promised to come up with a plan to resolve the problems. This led to the D2’s 6.9.2016 Email. Despite so, the matter could not be resolved, hence the need for this litigation.

38.  Black rainstorm signal was issued by the Hong Kong Observatory (“HKO”) in the morning of 24 May 2017.[20] On even day, Ah Tung attended the Plaintiff’s Flat for inspection. Humidity test revealed serious dampness on the ceilings of EDB, causing the paint to bulge. In addition, new water leakages were spotted in the STOR. Ah Tung suspected that the water could come from the external wall or the Common Roof. For the latter, there was a drain with domed grating on the Common Roof (the “Drain”) connected to a downpipe which ran vertically down and passed through the DC inside the STOR.[21]

39.  After several days of heavy rainfalls in mid-June 2017, Ah Tung was once again instructed to inspect the plaintiff’s Flat between 10 and 20 June 2017. Visual inspection showed that the condition in the EDB continued to deteriorate. As to the STOR, he was confident that the leakage was caused by rain water, as the condition became worse on days that rained.[22] He remarked that the water could come from the 34/F or the external wall, with the latter being more probable.

40.  Inspection by Ah Tung on 15 August 2017 revealed water seepage at both the external and internal walls of the SH.[23] The inspection conducted on 24 August 2017 (after typhoon signal no. 10 was hoisted on 23 August 2017) showed that the water leakages at the SH and EDB became worse.[24]

41.  Dr Huan claimed that in light of the emails from the 2^nd Defendant, and the arrangements made for the Waterproofing Works and Repair Works, the 1^st and 2^nd Defendants are unquestionably responsible for the water leakage problems.

42.  As to the current condition of the Plaintiff’s Flat, Dr Huan complained that persistent water leakages have caused and continued to cause severe damage to its ceilings, walls and floor tiles. Paint was peeled-off; concrete spalled revealing the rebar that was embedded inside the ceilings. The rebar was rusted from the sustained dampness. These conditions, besides being unpleasant to the eyes, present a hazardous environment to the wellbeing of the family.

43.  Dr Huan clarified that any remedial works on the Plaintiff’s Flat would be redundant until the water leakage problems are resolved, which has yet to materialise due to the failures and continued procrastinating on the part of the 1^st and 2^nd Defendants. He said that the new floor tiles and furniture that replaced the damaged ones soon became damaged by the water. The undesirable state of the Plaintiff’s Flat created much stress and disturbance to Dr Huan and his family, especially to his elder daughter whose room suffered from the most damage.

44.  Dr Huan explained at trial that, at or about the time of the Flooding Test, Bathroom 4 inside the SR, which is directly above the STOR, was not usually used. He gave a history of the SR, saying that it used to be a guest room, but was later on converted into SR as there was no guest.

45.  At the end of his evidence-in-chief, Dr Huan confirmed that at the time of the trial, there continued to be water leakages at the SH, EDB, DR, LR2 and the STOR. Their conditions would become worse whenever there was heavy rainfall or typhoon.

His evidence under cross-examination

46.  Dr Huan clarified that he used guest room to describe EDB in his witness statement because it had become a guest room after his elder daughter had moved to the United States of America since 2010. He elaborated that the elder daughter would return to Hong Kong every summer and winter, and she would stay at the EDB. Bathroom 3, located inside EDB, would be used whenever she returned to Hong Kong or when a guest stayed overnight in the Plaintiff’s Flat. He added that the latter was rare, not more than a week for each year.

47.  On this topic, Dr Huan admitted that he and his wife would work abroad. For himself, he spent approximately 10% to 15% of the year outside Hong Kong. His wife travelled less, as she had to look after the daughters.

48.  For the STOR, notwithstanding the water leakage, it was still in use. Dr Huan explained that around 70% of the STOR was still usable (for storage of some boxes). The remaining 30% was affected by the water leakage.

49.  In spite of his complaints that the water leakage started in 2013, Dr Huan agreed there was neither photograph taken nor written records to show the same. Particulars of the problems were also omitted from his witness statement. He denied that there was no water leakage in the Plaintiff’s Flat until May 2016. In his replies, Dr Huan stressed that verbal and face-to-face complaints were made to the staff of the 2^nd Defendant at its office but to no avail. He had also sought assistance from the chairman of the 1^st Defendant at that time, Mr Mark Ng (“Mr Ng”). Dr Huan recounted that Mr Ng said the 1^st Defendant wanted to repair the water leakages in all 3 Towers within the Estate, but the insurance policy debarred them from taking any action when there was on-going litigation.

50.  Dr Huan had no quarrel with Mr Lee’s suggestion that the Management Agreement of the 2^nd Defendant had been renewed once every 3 years from 2007 to 2019. At the time of the trial, it was still the manager of the Estate. When asked, Dr Huan answered that he could not be sure whether the 1^st Defendant was satisfied with the performance of the 2^nd Defendant.

51.  Equally, Dr Huan had no disagreement with the fact that the 2^nd Defendant had hired Hong Dau to undertake the Renovation Works, Waterproofing Works and Repair Works, from 2012 to August 2017. He also confirmed that the Renovation Works included repair works on the roof.

52.  Mr Lee then referred Dr Huan to the first of the Ah Tung’s Emails, i.e. the one dated 25 May 2016.[25] Relying on the wordings used under §1 of the same, Mr Lee suggested that there was water leakage at 1 room only, and that 1 room was the EDB. This was refuted by Dr Huan. He expounded that apart from the EDB, other rooms on the 34/F were also affected.

53.  Mr Lee’s questions then turned to how the 2^nd Defendant had discharged its duties. Staying with Ah Tung’s email dated 25 May 2016, Dr Huan agreed the same recorded that:-

(1) staff of the 2^nd Defendant attended the Plaintiff’s Flat on 16 May 2016, i.e. the 1^st Inspection, after complaint was lodged on even day;

(2) the staff assured that arrangement would be made with Hong Dau to follow-up on the problems;

(3) a week later, on 23 May 2016 (the 2^nd Inspection), a staff of the 2^nd Defendant and a staff of Hong Dau attended the Plaintiff’s Flat for inspection;

(4) Hong Dau’s representative said they would render further inspection after it had rained.

54.  Apart from the aforesaid, in Ah Tung’s email dated 1 June 2016[26], it was confirmed that arrangement had been made for the Waterproofing Works to commence on 2 June 2016.

55.  Relying on these emails, Mr Lee suggested, first, it was reasonable for Hong Dau to render further inspection after rainfall, and second, the arrangement for the commencement of the Waterproofing Works was swift as it only took 1 week after the inspection on 23 May 2016. Regarding the former, Dr Huan pointed out that he was not in the position to give an opinion on it. As to the latter, his reply was that, as a tenant, he would want the matter to be resolved as quickly as possible.

56.  Dr Huan’s attention was drawn to D2’s 12.7.2016 Email.[27] It was reported therein (to Ms Daisy Wong) that after commencement of the Waterproofing Works on 20 June 2016, tests conducted on 27 and 28 June 2016 revealed no leakage. The Waterproofing Works were concluded on 9 July 2016. Mr Lee asked whether Dr Huan would consider the time used from start to finish of the Waterproofing Works as reasonable. Again, Dr Huan replied he was not one to pass any judgement on the length of time that would be regarded as reasonable. From a tenant’s perspective, he would certainly want the problems resolved as soon as possible. He ended this topic with the remark that it took almost 2 months from the 1^st Inspection to the completion of the Waterproofing Works.

57.  Mr Lee’s cross-examination then brought Dr Huan to the water leakage in September 2016. D2’s 6.9.2016 Email[28] to Ms Daisy Wong was used as an opening for this episode. Dr Huan agreed that on even day, a staff of the 2^nd Defendant attended the Plaintiff’s Flat to investigate on the complaint. The subject water leakages were found at DR and MAR. Pausing here, in the midst of giving his answers, Dr Huan confessed that there was no water leakage at the EDB in September 2016. But he later added that, leakage had stopped after completion of the Waterproofing Works, until its return in September 2016.

58.  Dr Huan agreed that for the water leakage in September 2016, only those at DR and MAR were documented. He also admitted that no water leakage was seen at the DR by the end of 2016. That being said, Dr Huan remarked that even though he did not notice any water leakage at EDB and DR, it did not mean the problems were resolved.

59.  It was agreed by Dr Huan that there was neither any photograph nor documentation showing spalled concrete inside the Plaintiff’s Flat. He also accepted that the quotation for repairing the damage dated 26 January 2018 did not include any item for spalled concrete (see §103 of this judgment).[29] Despite so, Dr Huan disagreed that it did not exist.

60.  Relying on the email from Ah Tung to Dr Huan dated 6 September 2016,[30] Mr Lee queried whether Argent had provided repair works on the Plaintiff’s Roof. Although Ah Tung had mentioned therein that Argent had completed some works on the Plaintiff’s Roof, and a reminder that the warranty for the same would not cover any damage caused by the 2^nd Defendant and Hong Dau, Dr Huan insisted that no repair was done by Argent on the Plaintiff’s Roof. He explained that Argent only performed some works on the ceiling of the EDB. He later clarified that he had no knowledge of what had or had not been done. He could not recall whether there was any repair or waterproofing works performed by Argent. Neither could Dr Huan comprehend why Ah Tung sounded so concern about possible damage that could be caused on the works that Argent had done on the Plaintiff’s Roof, citing that he was not an engineer.

61.  Ultimately, Dr Huan admitted that Argent had done some works on the Plaintiff’s Roof to stop water leakages. However, he had no recollection as to when it was performed, and the extent of the works.

62.  Finally, Dr Huan reiterated that the Waterproofing Works had worsened the water leakages in the Plaintiff’s Flat. He refused to accept that the works done by Argent could possibly brought about the same result, as he saw no such phenomenon after Argent completed the task.

His evidence under re-examination

63.  Mr Chiu started his re-examination with Dr Huan’s complaint to Mr Ng. A letter dated 15 August 2018[31] issued by the latter, in his capacity as a chairman of the 1^st Defendant, was referred. Mentioned in it was the litigation between the 1^st Defendant and Hong Dau, under which Hong Dau was suing the 1^st Defendant for withholding HK$930,590 to set-off the costs of outstanding defects, which was certified by CBRE. In addition, Mr Ng acknowledged that there were water leakage issues in all Towers within the Estate, and showed his understanding of the owners’ frustration with the lack of corrective action. Promise was given that the corrective action could be taken within 3 months. Dr Huan confirmed the contents of the same, and said that all along the 1^st Defendant was aware of the water leakage issues within the Estate, including the Plaintiff’s Flat. In fact, Mr Ng had inspected the Plaintiff’s Roof, and at the same time the roof which belonged to Dr Huan’s neighbour, and concluded that the conditions were dire. Mr Ng assured that he would discuss about this at the management committee meeting. Nevertheless, due to the present action, the management committee received legal advice that no repair work should be performed.

64.  As to the works done by Argent on the Plaintiff’s Roof, Dr Huan maintained that he did not know the scope and nature of the same. However, he concurred that if the works involved waterproofing membrane beneath the titles, Argent would have informed him and the 2^nd Defendant, and there was no such notification.

65.  On the question of spalled concrete, Dr Huan clarified what he actually meant was that there was structural damage, i.e. cracks inside the ceiling. He referred to the photographs showing the structural damage in the STOR.[32]

66.  That concludes Dr Huan’s evidence.

67.  In the sections below, I will first set the respective solo reports of Dr Lam and Mr Mak, followed by their joint expert report. Their evidence at trial will come afterwards.

DR LAM’S SOLO REPORT

68.  Dr Lam adopted his solo report dated 1 February 2018 (“Lam’s Solo Report”) [33] as part of his evidence-in-chief.

Dr Lam’s observations

69.  In Lam’s Solo Report, Dr Lam first set out the observations he had during his visits to the plaintiff’s Flat and plaintiff’s Roof. The first of which took place on 5 May 2017. He saw paint peeling-off from the ceiling of the EDB, with signs of water damage. The paint at the ceiling of DR was also peeled-off. He was given to understand that water had been dripping from the ceiling of DR, and buckets were used to collect the water. Dr Lam noticed that immediately above the EDB and DR was the Common Roof; for the latter, the Lift Motor Room 1 was directly above it.

70.  As there was no plumbing or concealed water pipes inside the roof slab, Dr Lam thought that rainwater was the source of the water leakages at EDB and DR. Furthermore, since the damage found at the ceilings of EDB and SR were in close proximity with the Common Roof, he believed that these were the likely locations where rainwater penetrated through the roof slabs and caused the water leakages therein.

71.  During the inspection, Dr Lam noticed that there should be recent replacement of some of the tiles on the Common Roof area, as the new tiles were evidently whiter in contrast with the old ones.[34]

72.  The 1^st Joint Expert Inspection brought Dr Lam back to the Plaintiff’s Flat and Roof. Apart from revisiting the EDB and the DR, he was shown the STOR, SH, and the external wall of YDB.

73.  Regarding the STOR, Dr Lam saw obvious signs of water seepage and the paint peeling off from the ceiling, edge beam above the window, and the walls that housed the DC.[35] He suspected that the water seepage could come from Bathroom 4 and/or rainwater. For the latter, it could be a result of water ingress from the external wall and/or seepage inside the DC.

74.  As to the SH, Dr Lam noticed that the internal wall under it suffered from water damage as evidenced by delamination of paint.[36] He considered the source of water seepage could be from the SH or another duct chamber at the back of the internal wall. Apart from this, he saw signs of water damage (i.e. watermarks and paint peeling off) at the SH’s wall around the roof slab level.[37] Dr Lam believed that the source of water seepage was rainwater leading to possible water ingress from the Plaintiff’s Roof, the exterior walls of SH,[38] or the roof of the SH.

75.  For the YDB, Dr Lam spotted that the upper part of the external wall was subjected to ingress of water as evidenced by watermarks and peeling off of the paint. He remarked that it was likely due to ingress of water from the external wall or the Plaintiff’s Roof immediately above the YDB.

76.  On this occasion, Dr Lam noticed from the Common Roof that there was another recent repair on various parts of the roof slabs.[39] One of them was at a corridor which was situated between the SH and Lift Motor Room 1 (“Common Corridor”). The location of the Common Corridor can be seen from Plan 3.

77.  During the 2^nd Joint Expert Inspection, photographs were taken at EDB, DR, STOR, SH, the Plaintiff’s Roof and the Common Roof.

The Flooding Test

78.  As aforementioned, the Flooding Test commenced on 6 November 2017 and ended on 15 November 2017, a span of 10 days. In Lam’s Solo Report, Dr Lam expounded on the methods adopted, schedule of works, division of works and the results of the Flooding Test. And before commencement of it, the experts had agreed on the following matters:-

(1) The Flooding Test was conducted using water without dye or tracer.

(2) The flooding and infra-red thermography were performed by Fugro Technical Services Limited – MateriaLab Division (“Fugro”), whereas the Test and Measurements (as defined in §79 below) were carried out by the experts.

(3) As there was no suitable location for infra-red thermography, exterior of the external wall was not assessed.

(4) Locations of water seepage at 33/F, internal walls under SH, and the walls of SH, were excluded from the flooding. Nevertheless, Tests and Measurements were performed.

79.  On 6 November 2017 (adopted by the experts as “Day 0”), preparations were made for the Flooding Test to be conducted at part of the Common Roof (excluding the area where the Drain is located). There was also inspection at the Plaintiff’s Flat, where readings on the surface moisture content of the ceilings and walls were obtained using protimeters and infra-red thermography (“Tests and Measurements”).

80.  On 7 November 2017 (adopted as “Day 1”), the Flooding Test started by flooding part of the Common Roof (including the lower portion of parapet walls thereon) with water to a minimum hydrostatic head measuring not less than 25 mm throughout the area, and the flooding would be maintained for 24 hours. Tests and Measurements were carried out after the minimum hydrostatic head was achieved.

81.  Tests and Measurements were again carried out on the next day, i.e. 8 November 2017 (adopted as “Day 2”). The hydrostatic head was thereafter released upon agreement of the experts.

82.  The final Tests and Measurements were taken on 15 November 2017 (adopted as “Day 8”).

83.  Dr Lam selected 13 areas for the Tests and Measurements that he conducted. They include locations 1 to 4 at the ceilings of the EDB, locations 5 (wall at the floor level of the SH) and 6 (at the interior wall of the SH), location 7 at the ceiling of DR, locations 8 to 11 inside the STOR (Location 8 at the upper part of DC facing inward from the window; location 9 at the ceiling of STOR adjacent to DC; location 10 at the upper part of DC close to the window; location 11 being the wall above the window inside the STOR), location 12 as the control point, and location 13 at the external wall of YDB. Dr Lam explained that location 12, being the control point, served as reference readings of the surface moisture content unaffected by water seepage.

84.  As we shall see later on in this judgment, Mr Mak had adopted different descriptions and numberings for mostly the same locations Dr Lam used for his Tests and Measurements. To avoid confusion, I will, from this point onward, refer to the locations used by Dr Lam collectively as Lam’s Locations (or individually, for example, as Lam’s Location 1).

85.  At each of the Lam’s Locations, points were assigned at approximately 150 mm by 150 mm grids. Surface moisture content was measured using a protimeter at 3 times per point. Dr Lam described protimeter as a handy equipment with readings from 0 to 100. Readings above 30 to 35 suggest wet areas. These would be compared to that of the control point at Lam’s Location 12.

86.  Pausing here, I wish to mention that the protimeter used by Dr Lam was an electrical resistance (conductance) meter (“ERM”), whilst Mr Mak used another type of equipment, namely electrical capacitance (dielectric) meter (“ECM”). Both the ERM and ECM were electrical moisture meter (“EMM”), which is said to be a traditional conductive type of meter that measures moisture levels in affected areas. As we shall see later on in this judgment, the difference in the type of EMM used by the experts is also a hotly contested subject in this case.

87.  Returning to the Flooding Test, Dr Lam said that it was agreed between the experts that “fine weather” was defined as daily total rainfall of not more than “trace”. By “trace”, it meant that the total daily rainfall was less than 0.5 mm. With reference to the Daily Total Rainfall (mm) provided by the HKO, Hong Kong was subjected to fine weather from 18 October 2017 to 11 November 2017. Although there were 0.3 mm of rainfalls on 4 and 7 November 2017, the same were insignificant or negligible to have any effect on the Flooding Test. It was also noted that there were 2 rainy days on 12 and 13 November 2017, with daily total rainfall at 14.7 mm and 12.5 mm respectively.

Results from the Flooding Test

88.  With the table set, Dr Lam then provided the results of the Tests and Measurements that he carried out, and the results of infra-red thermography performed by Fugro.

89. For his part, ERM readings obtained from Lam’s Locations indicated that there was no high surface moisture content recorded from Day 0 to Day 2. The same could not be said for Day 8. The ERM readings revealed that, out of the 3 Lam’s Locations (namely Lam’s Locations 1, 2 and 4) inside the EDB, 7 points was found to have high surface moisture content. The same result was found at 1 point within Lam’s Location 5. Finally, amongst the 3 Lam’s Locations (Lam’s Locations 9 to 11) inside the STOR, there were 10 points with high moisture readings.

90.  As to the infra-red thermography results, surface moisture was observed on Day 8 at the ceiling of STOR and the walls of the DC. There was no report on surface moisture at the other Lam’s Locations.[40]

Dr Lam’s views on causes of water seepage

91.  Based on the above results, Dr Lam took the view that the water seepage came from rainwater. In his opinion, the issue was whether the seepage originated from the Common Roof, the Plaintiff’s Roof and/or the external wall.

92.  For the EDB, Dr Lam concluded that the water should come from the Common Roof, as the Lam’s Locations inside EDB with high surface moisture all sat below the same, and were far away from the Plaintiff’s Roof. The ingress of water indicated that the waterproofing membrane underneath the Common Roof was defective.

93.  Regarding the DR, results of the Flooding Test was non-conclusive, as the Tests and Measurements did not indicate high surface moisture content at its ceiling. Dr Lam added that, based on the previous complaint of water dripping down from the ceiling, the ingress of water would take place within hours after the flooding on Day 1 or within hours after rainfall on 12 and 13 November 2017. Amid the lack of high moisture content, Dr Lam suggested that it could be the result of the recent repair at the Common Roof (see §76 above), in particular the repair seen at the Common Corridor, which sat almost directly above the DR. Dr Lam’s view, from hindsight, was that the water seepage at DR was a consequence of the defective waterproofing membrane at the Common Corridor. Furthermore, he eliminated the possibility of water seepage stemming from the Plaintiff’s Roof, as the same was not close to the spot of the seepage found inside the DR.

94.  As to the STOR, Dr Lam pointed out that high moisture content was found at the points in close proximity to or on the walls of DC, and the external wall above the window of STOR. He remarked that the seepage originated from ingress of rainwater via the external wall and the Common Roof. For the latter, Dr Lam expounded that the Drain sat directly on top of the DC, and when the rainwater collected from the Common Roof was discharged via the Drain, it would flow through the downpipe located inside the DC. Dr Lam came up with 3 possibilities which caused the water seepage at the DC: (1) the water leaked out from the downpipe; (2) the water leaked along the edges of the Drain; and/or (3) the water penetrated through the defective waterproofing membrane on the Common Roof in the vicinity of the Drain. Dr Lam added that he had tried to inspect the condition of the DC at 34/F. However, as the same was cladded with tiles finishes, the outcome of the inspection was non-conclusive.

95.  Turning to the walls of the SH which is located at the floor level of the same (i.e. Lam’s Location 5), high surface moisture content was found. Dr Lam said that the water seepage could originate from rising dampness, consequential of: (1) ineffective waterproofing, for example, at the upturn of the Plaintiff’s Roof; and/or (2) ineffective waterproofing above the SH, permitting ingress of water through the walls. For the latter, Dr Lam referred to photograph no 35 appended to Dr Huan’s witness statement as illustration of how the waterproofing was ineffective.[41]

96.  Regarding the internal wall of the SH, despite that no ERM reading was recorded as the affected area was 3 to 4 metres above the floor level and inaccessible, Dr Lam remarked that the water seepage was likely caused by ingress of water from the Plaintiff’s Roof.

97.  Finally, the cause of the water seepage to the external wall of YDB was non-conclusive. Dr Lam said that the same could stem from ingress of rainwater either via the external wall or the Plaintiff’s Roof.

Costs of repair

98.  This topic formed the last part of Lam’s Solo Report. Under this part, Dr Lam first set out the remedial works that were required.

99.  Dr Lam emphasised on the importance of having the water seepage problem alleviated before commencement of the redecoration works. To achieve this, he suggested to have the defective waterproofing membrane replaced at the Common Roof, followed by flooding, and then inspection to be conducted for signs of water seepage in order to verify its waterproofing ability. He was against patch repair (i.e. repairing only the defective area), due to incompatibility between the new and old waterproofing membranes, which could allow ingress of water at the interface. The common practice or the most effective means, he explained, was to replace all waterproofing membrane under the Common Roof.

100.  For the walls of the SH (at floor level and the internal walls) and the external wall of YDB, Dr Lam suggested that the ingress of water was neither enormous nor at a fast rate. He found it necessary to first hack off the paints to open up the concrete for inspection. In the presence of poor quality concrete, which he said would likely be found on the walls of the SH, cracks and pores would have to be sealed by epoxy grouting to block the water paths. Afterwards, a polymer modified cementitious screeding with waterproofing ability should be applied to prevent ingress of water. Paint would be applied at the end.

101.  Regarding the ceilings at EDB and DR, Dr Lam reiterated the significance of having the waterproofing membrane at the Common Roof replaced. After this, and with the flooding test showing that the seepage problem had been cured, screeding, insulation boards and roof tiles could be re-laid. The redecoration works within the Plaintiff’s Flat could commence 60 days thereafter. Dr Lam advocated that the works at the Common Roof should be performed by the 1^st and 2^nd Defendants, as they were responsible for the waterproofing membrane (amongst the Subject Common Parts), and these works might affect other owners.

102.  For the STOR, Dr Lam provided that remedial measures would have to be based on trial and error, to eliminate the possible cause of water seepage. He recommended that repair works at the Common Roof should be the starter, with the initial focus being on the Drain. If the repair at the Drain was done but seepage persisted, it would then be necessary to break open the DC to check for possible leakage from the downpipe. If there was, the same would have to be replaced. Where there was no leakage found at the downpipe, or the seepage persisted even after replacement of the downpipe, it would fortify the need to have the waterproofing membrane on the Common Roof replaced. Favourable results from the flooding test thereafter would provide the greenlight for commencement of redecoration works at the STOR and the DC therein.

103.  Based on the above, Dr Lam obtained a quotation from Southern Skies Hong Kong Ltd (“Southern Skies”) dated 27 December 2017, estimating that the costs would be HK$257,000, comprising of: (1) HK$52,000 for EDB; (2) HK$75,000 for the STOR; (3) HK$45,000 for DR; (4) wall at floor level of SH at HK$25,000; and (5) HK$60,000 for the internal walls of the SH.[42]

MR MAK’S SOLO REPORT

104.  Mr Mak’s solo report dated 20 March 2018 (“Mak’s Solo Report”) [43] was adopted as part of his evidence-in-chief at trial.

Mr Mak’s observations

105.  For the 1^st Joint Expert Inspection, Mr Mak commented that the weather on that day was fine. However, he added that just 2 days before the 1^st Joint Expert Inspection, i.e. on 24 May 2017, there was rainfall of about 273 mm pursuant to the record of the HKO. Moreover, it had been raining almost continuously for a month prior.

106.  His narratives begun with the areas that he inspected inside the Plaintiff’s Flat. Apart from the EDB, DR and the Common Roof that the experts were instructed to inspect, Ms Daisy Wong also brought them to the SR, YDB, LR2 and MAR where there were allegedly water seepage problems.

107.  At the EDB, Mr Mak saw patches of water stains or marks at the ceiling near the wardrobe and at the centre above the bed. Inside the DR, he noticed a patch of peeling paint near the centre of the ceiling and beside the fluorescent tube. Mr Mak added that the stain mark was not so obvious as compared to those seen inside EDB. Furthermore, he did not see any stain mark on the floor tiles directly underneath the stain found on the ceiling.

108.  The 1^st Joint Expert Inspection also brought Mr Mak to the Common Roof, including the Common Corridor. He noticed that the floor of the same was finished with cement roof tiles. However, the tiles on the part of the Common Roof which sat above EDB and SR were of different colour and looked newer as compared to the rest. This, he said, indicated that the roof tiles on the said portion were recently replaced. In addition, Mr Mak also provided in his solo report that the floor level of the Common Roof was about 50 mm higher than the floor level of the Plaintiff’s Roof. The tiles used on the Plaintiff’s Roof were also different from those on the Common Roof.

109.  Regarding the other areas that he visited, the following conditions were observed:-

(1) In LR2, near the window, there were patches of marks around the window frame and sides.

(2) At the wall near the window inside YDB, there were patches of marks and peeling paint at the top of the same near the ceiling. Mr Mak also saw water stains and marks along the window frames and sides.

(3) He could see paint peeling off along the internal walls of the SH.

(4) There were water stains or marks, and paint peeling patches beneath part of the air-conditioning ducts under the ceiling of 34/F.

(5) At the SR, a stain patch could be seen above the window.

(6) Water stains or marks were seen at the walls of the SH (at floor level).

(7) The ceiling around and at the side walls of the DC were full of dark marks, which he believed to be mould, water stains, and peeling paint and plaster. Mr Mak remarked that the marks were extensive from top to near the bottom.

110.  Mr Mak ended his report on the 1^st Joint Expert Inspection with a note that he saw no sign of water dripping or water seepage at the said areas.

111.  During the 2^nd Joint Expert Inspection, Mr Mak re-visited the STOR, MAR, EDB, YDB, DR, walls of the SH at floor level, the internal walls of the SH, and the Common Roof including the Common Corridor. He observed that, notwithstanding the passing of time between the 1^st and 2^nd Joint Expert Inspections, and the rainy season during the same (from June to September), there was no apparent deterioration in the conditions of these affected areas.

The Flooding Test

112.  In Mak’s Solo Report, Mr Mak gave much coverage on his communications with Dr Lam regarding the method to be adopted for the Flooding Test, which I do not find it necessary to reproduce them in this judgment. Suffice it to say they eventually agreed on the method, schedule and division of work (Fugro to do the flooding and infra-red thermography). That being said, Mr Mak had in his email to Dr Lam highlighted his disagreement to have the infra-red thermography, on the bases that it was not a standard test within the building surveying practice, and the test result would be subject to special interpretation. In fact, Mr Mak was quite critical of the infra-red thermography conducted by Fugro, in spite of its overall results being favourable to the 1^st and 2^nd Defendants.[44]

113.  Suitability to have the Flooding Test conducted at the relevant period, considering the record from HKO, was not contended.

114.  Preparations were made on Day 0 for the Flooding Test to be performed on the next day. Whilst this was going on, Mr Mak said that the experts conducted the initial Tests and Measurements. In Mak’s Solo Report, he set out the locations that he adopted for such purpose. These locations were mostly the same as those adopted by Dr Lam, but with different descriptions and numberings. The locations Mr Mak adopted are reproduced below (with Dr Lam’s numberings and descriptions contained in brackets and italicised):-

(1) Location 1: the ceiling of EDB above the entrance door (same as Lam’s Location 1).

(2) Location 2: the ceiling of EDB above the wardrobe (same as Lam’s Location 2).

(3) Location 3: the ceiling of the EDB over the passage leading to Bathroom 3 (ceiling of EDB but no specification as to its location; presumably same as Lam’s Location 3).

(4) Location 4: the middle part of the ceiling of EDB above the bed (same as Lam’s Location 4).

(5) Location 5: the top inner side of the external wall inside YDB, adjacent to the window (Lam’s Location 13).

(6) Location 6: the ceiling of DR adjacent to the fluorescence tube (Lam’s Location 7).

(7) Location 7: at the skylight well, being the walls on the two sides of the void over the ISS (not included in Lam’s Locations).

(8) Location 8: wall of SH at floor level (Lam’s Location 5).

(9) Location 9: internal walls of SH (Lam’s Location 6).

(10) Location 10: ceiling of the STOR adjacent to the DC (Lam’s Location 9).

(11) Location 11: wall above the window inside the STOR (Lam’s Location 11).

(12) Location 12: wall at the top of the DC facing the door of STOR (Lam’s Location 8).

(13) Location 13: wall of the DC adjacent to the window of STOR (Lam’s Location 10).

115.  Pausing here, aside from the difference in numberings, it could be seen from the above that Mr Mak did not adopt a control point like Dr Lam; equally the walls on the two sides of the void over the ISS underneath the skylight well was seemingly not adopted as an inspection point by Dr Lam.

116.  For clarity sake, the Lam’s Locations, including the control point at Lam’s Location 12, will be adopted in this judgment. Where reference to the walls on the two sides of the void over the ISS underneath the skylight well is required, it shall be represented by “Mak’s Location 7”.

117.  Whilst conducting the Tests and Measurements, Mr Mak identified a problem with the ceiling of the EDB, i.e. there was a false ceiling installed therein. Mr Mak said that the false ceiling used timber batten as the base underneath the concrete slab ceiling, and probably used gypsum board as the finishing face. In case there was any moisture or water seepage through the concrete slab, it was highly likely that the water would pass through the timber batten frame first, then saturated at some portions or locations and run along the timber grid before directly affecting the facing board at the bottom of the system. If there was any facial stain mark on the facing board, it might not be the direct corresponding location of the leakage spot at the concrete slab. Furthermore, in case the leakage was of sufficient quantity, the water would be difficult to drain out and might require more time than normal to fully evaporate out. Hence, the water could be trapped within the void of the grid and saturated the facing board causing a much larger area of stain mark than the spot of the leakage. There could also be a delay in detecting the leakage from the time it started dripping to the time when the stains appeared. In short, the false ceiling could be a hindrance to the proper investigation of any water seepage problem.

118.  Mr Mak also took the opportunity to criticise the method used by Dr Lam. As mentioned in §85 above, at each of the Lam’s Locations, Dr Lam assigned points at approximately 150 mm by 150 mm grids. Mr Mak expanded on this, saying that the points were marked around each patch of stain mark or peeling paint. Although he agreed that these pattern of grid points would aid in the Tests and Measurements that were repeated during the Flooding Test (i.e. the same performed on similar locations and getting the average moisture content around the area), Mr Mak said the downside of such method was that it might not be good at pin-pointing any particular spot of leakage, unless the points fell into a leakage spot.

119.  Mr Mak said he had used a protimeter to conduct the Tests and Measurements; nevertheless, the machine he used was ECM. He explained that ECM was an electromagnetic sensing, non-destructive, on-contact measuring equipment. It was capable of taking a reading range from 0% to 100% of moisture content of any material brought into contact of the sensor head. The reading of 0% represented a dry, non-contact situation after calibration (i.e. with the air); conversely, a reading of 100% represented a saturated condition of the material (e.g. at a piece of soaking wet paper) at the point of contact. The ECM would not give any reading even if the sensor head was brought very close to an object, short of contacting. Mr Mak added that the ECM was suitable for measuring any non-metal porous materials capable of capturing any moisture of water.

120.  Whilst he was conducting the Tests and Measurements, calibration was done every time when the ECM was switched on (which would show a reading of zero). After calibration, Mr Mak would use the ECM to test the background average moisture content of the walls and relevant objects in the Plaintiff’s Flat. When he tested the lower portions of the internal walls at various areas of the same, the readings obtained ranged from 40% to 47%. These walls had no obvious water stains or marks. When Mr Mak tested the ECM on a piece of paper on the deck top, the reading was about 13%, which indicated a normal dry condition.

Results of the Flooding Test

121.  Same with Dr Lam, Mr Mak conducted 4 sets of Tests and Measurements on Day 0, Day 1, Day 2 and Day 8. They were conducted at the grid points set down by Dr Lam for the Lam’s Locations. However, Mr Mak had also taken the liberty to measure a few more spots outside these grid points.

122.  Mr Mak adopted the results on Day 0 as the initial base line of the moisture content at all the locations. He said that the results gathered on Day 1 and Day 2 were critical to monitor any immediate water leakage caused by fracture or defects that might be present underneath the flood-tested areas. Results of Tests and Measurements gathered on Day 8 served to monitor any further slow seepage and migration. If the results on Day 1 and Day 2 showed immediate leakage, the results on Day 8 should reveal the regression of the same.

123.  For the EDB, YDB, DR, internal walls of the SH, wall of the SH at floor level, and the walls at the skylight well, the Tests and Measurements conducted by Mr Mak revealed that there was slight increase of moisture between Day 0 and Day 8. Based on the results, Mr Mak concluded that there was no continuing water leakage at these locations.

124.  As to the STOR and DC, the Tests and Measurements conducted between Day 0 and Day 2 showed that the readings were much higher than normal and as compared with the other locations. Mr Mak pointed out that this was an indication that the STOR and DC were constantly in wet condition. On Day 8, his ECM readings showed that at Lam’s Locations 8, 9 and 11, there was no increase in measurement values. Only at Lam’s Location 10, i.e. the wall of the DC adjacent to the window of STOR, experienced substantial increase of moisture, with some spots at saturation (100%). Mr Mak suggested there could be some water attack at Lam’s Location 10. Overall, Mr Mak concluded that the ceiling of STOR and the walls of DC were subject to moisture or water seepage attack. However, he added that the Flooding Test performed at the Common Roof could not provide any direct evidence for the cause or source of these problems. He recommended investigation at Bathroom 4 for possible floor or piping leakage.

Costs of repair work

125.  In light of the above, Mr Mak considered that the 1^st and 2^nd Defendants were exempted from conducting further investigation within the Plaintiff’s Flat and Roof. Probably for the same reasons, he had not provided any estimation of the costs of repair in Mak’s Solo Report.

THE JOINT EXPERT REPORT DATED 23 OCTOBER 2018 (“JER”) [45]

126.  The JER was produced after the experts’ solo reports were exchanged. It recorded their agreements and disagreements, and their views on the latter. As a preview, not much could be agreed between them. Their disagreements, so intensive and extensive, suffice as issues supplementary to those I have set out in §25 of this judgment.

127.  I will first provide the agreements hereunder:-

(1) The roof of Tower 2 of the Estate was divided into the Plaintiff’s Roof, the Common Roof, and a roof private to Flat B.

(2) For the Flooding Test:-

(a) water without dye or tracer would be used;

(b) the flooding and infra-red thermography were performed by Fugro, whereas Tests and Measurements were carried out by Dr Lam and Mr Mak;

(c) as there was no suitable location for infra-red thermography, exterior of the external wall was not assessed; and

(d) for the locations of water seepage at 33/F, the internal wall under SH, and the walls of SH, they were excluded from the Flooding Test, but Tests and Measurements were performed.

(3) The rainfalls on 12 and 13 November 2017 had caused no adverse results to the Flooding Test.

(4) Ceiling of EDB was subjected to peeling off paintwork and signs of water damage.

(5) There were signs of recent repair works on the part of the Common Roof, and these were above the locations of high surface moisture content recorded on the ceiling of EDB.

(6) Water seepage at DR had ceased by the time of the Flooding Test.

(7) There was one location at the SH walls (floor level) with high surface moisture content. As the water damage was close to the floor level, the water seepage likely originated from rising dampness as a result of: (a) ineffective waterproofing at upturn of the Plaintiff’s Roof; and/or (b) ineffective waterproofing above the SH, permitting ingress of water through the walls. Mr Mak added a third possibility, i.e. the external portion of the wall was not waterproofing and permitted water seepage.

(8) It was non-conclusive as to the cause of water seepage found at the external wall inside YDB. It could be the result of ingress of rainwater from the external wall or from the Plaintiff’s Roof.

The control point issue

128.  In the JER, Dr Lam first clarified that the control point at Lam’s Location 12 was actually Mak’s Location 7. He conceded that no infra-red thermography was performed at Lam’s Location 12, as it was unnecessary to do so. He said that the infra-red thermographic image alone could determine signs of high surface moisture content. This was rejected by Mr Mak, saying that having infra-red thermography done at Lam’s Location 12 could form a complete reference.

129.  It is appropriate to highlight at this juncture that, at trial, Dr Lam once again corrected himself on the location of the control point. Lam’s Location 12 was actually near the DC on 33/F.

The protimeter issue

130.  The experts’ arguments on how the Tests and Measurements should be conducted served as an opening for this issue. Dr Lam highlighted that the results he obtained were based on 3 measurements made at each grid point. This, he said, was not a matter of personal choice as suggested by Mr Mak, but a necessity. He commented that adhering to such protocol was imperative especially when one used the ECM for measurements. The reason being that as a non-contacting device, ECM is an inferior product that could give different readings on consecutive measurements at the same spot. To support his point, Dr Lam referred to his notes for the lectures that he gave to the officers of the Joint Office, Buildings Department and Housing Department (“JO”).[46] Mr Mak was indifferent to this, disagreeing with Dr Lam on the deficiency of the ECM and preferring on his own testing protocol.

131.  The experts took this issue further, arguing over whether the ECM could provide reliable results. Mr Mak saw no relevance in Dr Lam’s lecture notes. Dr Lam, with reference to the Professional Guide to water Seepage Investigation, Diagnosis, Testing & Reporting in Residential Buildings (the “Guide”) [47], argued that ECM could not even be regarded as a protimeter. According to the Guide, protimeter is a term specifically used to describe ERM, not ECM. Mr Mak retaliated by saying that both ERM and ECM are EMM, with the common aim of measuring moisture.

132.  To expand on his points, Dr Lam provided the catalogue specification on the CEM brand of ECM, the model (DT-128M) which was used by Mr Mak (the “Specification”).[48] He said that ECM sends out high frequency wave to an object and measures the bounce back. As a result, the reading reflects bulk properties of the object. Bulk properties change with moisture and increases the reading. Dr Lam stressed that ECM is not a commonly used equipment, and it is not used by JO to investigate causes of water seepage. In addition, as it is based on wave theory, reading is related to penetration depth. As per the Specification, penetration depth of ECM is 20-40 mm. Hence, reading is applicable to a continuum or solid object, and is questionable when applied to the ceiling of EDB which was installed with a false ceiling made of timber batten as the base with facing board, having a gap in between. The timber batten itself is also too thin, only 9-10 mm in thickness, which does not tally with the penetration depth of 20-40 mm required for ECM. Furthermore, Dr Lam said that the reading produced by ECM fluctuates when the object is inhomogeneous like concrete and finishes. As such, it is a common practice to take several readings at each and every location. Regrettably, Mr Mak had only taken one reading per spot.

133.  In Mr Mak’s lengthy replies to the preceding comments, one can reduce them to a simple point: both ERM and ECM are devices recognised and utilised within the industry, albeit they engaged application of different techniques in obtaining and analysing the moisture measurements. He underscored the importance for one to bear in mind that regardless of the types of EMM used, the readings are only approximate. Attention should be placed on the measurements obtained between Day 0 and Day 2, not the type of EMM that was used.

The readings issue

134.  Mr Mak challenged Dr Lam on the latter’s findings that there was no high surface moisture content recorded from Lam’s Locations between Day 0 and Day 2. Contrarily, Mr Mak said the results revealed that there was high moisture content at many of the Lam’s Locations during those days. For illustration, Mr Mak referred to certain grid points in Lam’s Locations with much higher reading of moisture contents as compared to other points within the same individual location. Dr Lam turned back such challenge by reiterating on the standard that only readings over 35 would be regarded as high surface moisture content. This is so notwithstanding the higher percentage of moisture or increased level of moisture at certain grid point as compared with the others within the same location was found within the first 3 days of the Flooding Test. The test is based on the common practice established by the JO.

135.  As to the results obtained on Day 8, Mr Mak re-emphasised that those recorded by him showed slight increase in the moisture content. Dr Lam disagreed with how one should look at the results. Based on Mr Mak’s Tests and Measurements on Day 8, Lam’s Locations 1, 2, 4, 6, 8, 9, 10, 11 and 13 achieved readings of 70% or more out of the maximum of 100% reading on ECM. According to Dr Lam, these readings should not carry the meaning of “slightly higher”.

136.  Dr Lam elaborated on his preceding comments by reference to the Specification again, in particular the moisture table of comparison (“ECM Moisture Table”). In it, the meanings of the readings are defined. For example, measurements taken on cement revealing result of 25% or lower is seen as “dry”. Reading between 25-50% represents a status of “risk”, whereas reading higher than 50% indicates that area is “wet”. Based on these standards, Dr Lam said it was inexplicable that when tested on the walls that were dry, majority of the readings obtained by Mr Mak using his ECM were greater than 50%, indications that they were actually wet. In fact, none of the walls that were supposed to be dry came back with readings lower than 25%. For these reasons, Dr Lam doubted the accuracy of the ECM used by Mr Mak.

137.  Dr Lam also set out the readings taken at Lam’s Location 12, i.e. the control point, which showed that the results from ERM produced consistent readings, whereas the ECM produced meaningless random values.

138.  Furthermore, the readings obtained by Mr Mak on a dry area could range between 41.6% to 68.4% giving a mean of 55%. On a wet area, the readings ranged between 66.8% to 93.4% for a mean of 80%. Dr Lam highlighted that based on these data, the reading in the 60% range could arise in both dry and wet conditions, further undermining its accuracy and reliability.

139.  Dr Lam did not stop there. He criticised Mr Mak’s data analysis for not following the common practice exercised by the JO, i.e. comparing individual data against other data obtained from the same day. Instead, his analysis was based on average, maximum or minimum values, which, according to Dr Lam, was not meaningful. Dr Lam also doubted the accuracy of the data collected by Mr Mak. He said that there were no data recorded on 20 grid points in Lam’s Locations, and data obtained from 120 unknown spots were added.

140.  Finally, the calibration method adopted by Mr Mak was called into question. As the calibration was done in the air, the ambient condition at the time of testing could affect the outcome of the readings. Dr Lam expounded that the ECM was calibrated in the air to give a “0%” reading for a “dry” and non-contact situation at each and every measurement. Such approach would give rise to different readings from different day, due to the change in the ambient condition, even though the moisture content remained the same. With these changes of the ambient condition every day, comparison with the reading at Day 0 was inappropriate.

141.  Mr Mak responded to all these by clarifying that he was not using “average”, “highest” or “lowest” measurements in search of any spot with wet condition. His adoption of taking the average measurements was to properly interpret and eliminate any background or ambient humidity effect, which was expected to be higher at the Mid-level and hill-side locations, especially during rainy seasons.

The Day 8 results issue

142.  The importance of the results obtained between Day 1 and Day 8 was another hotly contested subject for the experts. Dr Lam disagreed with Mr Mak’s comments on how one should use the results obtained on Day 8 (see §122 above). He said that the same were critical to the investigation. Dr Lam elucidated that concrete has low permeability and it would take days for water to pass through concrete and appear on the surface. As the present case involved slow rate of seepage, it was not uncommon to find no significant change to the readings in the first few days of the Flooding Test. Hence, there was the arrangement that the Tests and Measurements would be made over a period of time. Negative results obtained from Day 0 and Day 1 alone could not indicate that there was no ingress of water.

143.  Mr Mak’s reply started with the nature of concrete. He cited an alleged common knowledge within the industry that it is a porous substance. In addition, concrete slab of less than 150 mm in thickness are prone to cracks due to large differential temperature seasonal and daily cyclic changes, as well as other loading stresses and vibrations. For these reasons, Mr Mak said that any water trapped above the concrete slab would always find its way down through the cracks by gravity, with or without saturating the whole of the concrete structure. The Flooding Test would be a fast and sure way to test any roof leakage. However, none of the results on Day 1 and Day 2 showed any obvious water leakage or water dropping from the ceilings inside the Plaintiff’s Flat. It was only on Day 8 that the moisture became slightly higher, which required further interpretation.

144.  Dr Lam responded by repeating that concrete has low permeability and is not a porous substance. He also rejected the suggestion that concrete slab could easily develop shrinkage cracks and other hairline cracks. Dr Lam reiterated that the high surface moisture content obtained from the Tests and Measurements on Day 8 supported the presence of water leakage. He took the opportunity to distinguish the results of infra-red thermography performed by Fugro, claiming that the temperature differential at locations with moderate surface moisture content being too small for infra-red thermographic images to reflect effectively. Dr Lam also relied on Mr Mak’s own remarks that the results from infra-red thermography would require the data to be compared and verified by using other direct measurements, i.e. such as protimeter. Dr Lam added that, as many of the infra-red thermographic images do not correspond well to protimeter readings, direct interpretation from the same are questionable.

145.  Conceding nothing, Mr Mak argued that one could not rule out the possibility of the concrete slab on the Common Roof contained cracks and of porous status without investigation. Mr Mak remarked the fact that all roofs needed waterproofing membranes speaks for itself. Apart from this, Mr Mak disagreed that a reading of high moisture content signalled the presence of water leakage. He relied on the lack of such finding from infra-red thermography to support his point. Mr Mak placed much weight on the infra-red thermography results as it was a test insisted by Dr Lam.

146.  Dr Lam returned a jab to Mr Mak on the point of infra-red thermography, citing on the latter’s criticisms on the reliability of such test. Furthermore, Dr Lam said his proposal to carry out infra-red thermography test was only because it was “sort-of” a standard test in water seepage investigation. To this, Mr Mak scornfully expressed his disapproval, indirectly reprimanded Dr Lam for employing a test without purpose and dismissing its results lightly without examination.

The source issue

147.  Regarding the source of water seepage, Mr Mak disagreed with Dr Lam allegations that the culprit was rainwater. He also disputed that the seepage was caused by penetration of rainwater from the external wall and roof. Mr Mak criticised that by these comments, Dr Lam was actually making conclusive statement on the cause of the high moisture content points prematurely (at §5.1 of Lam’s Solo Report), without first evaluating the effectiveness of the Flooding Test, and the comparison to all the measurements, including the infra-red thermography. Mr Mak added that Dr Lam had failed to discuss on the effect of the false ceiling inside the EDB. In his replies, Dr Lam clarified that when he gave those conclusions, he had taken into account the results of the Tests and Measurements obtained on 15 November 2017, and the report of Fugro on infra-red thermography, which Dr Lam agreed with Mr Mak’s remarks that the result was subject to special interpretation. As to the false ceiling inside EDB, Dr Lam’s view was that it would not affect the outcome. He explained that if there was seepage from the concrete ceiling, the affected area would be confined to the space between the timber frameworks. Hence, the location of seepage at the concrete ceiling was close to the affected areas observed on false ceiling. In taking his last bite on this topic, Mr Mak chastised Dr Lam for inserting his conclusive statement at the middle of a discussion instead of reserving it for the conclusion section. He also repeated his criticisms of the infra-red thermography results and how the false ceiling could cloud the true location of water seepage inside the EDB.

Remedial works and their costs

148.  Under this section, Dr Lam repeated the views and the costs quoted by Sunrise as contained in Lam’s Solo Report. For Mr Mak, he had given detail suggestions as to the remedial works that should be done, if necessary. Suffice it to say, the costs that he estimated were higher than those quoted by Sunrise, i.e. in the total sum of HK$328,125.

149.  Having in the above set out the experts’ opinions on paper, their evidence at trial are provided in the sections below.

DR LAM’S EVIDENCE

150.  I shall dive directly to Dr Lam’s evidence under cross-examination.

151.  Mr Lee started his cross-examination by getting Dr Lam to agree that the parapet wall (the “Parapet Wall”) which separated the Common Roof directly above EDB from the Plaintiff’s Roof which housed the SH (see Plan 3 for its whereabouts) was aligned with the internal wall (the “Internal Wall”) situated below at the EDB (see Plan 2 for the location of the Internal Wall). Mr Lee then made the suggestion that if water penetrated the waterproofing membrane on the Plaintiff’s Roof and entered into its concrete slab, the water could travel horizontally to the ceiling of EDB. Dr Lam did not reject such possibility, but added that the chance of this happening in our case was low. He explained that for water to travel in such a way, there must be cracks in the concrete slab which guided the water’s flow, and the water tracks would appear as stains or marks on the ceiling from the exterior all the way to the interior of EDB. He supplemented that the Parapet Wall and the Internal Wall seemed not only aligned but could even be one single continuous wall. In such a scenario, the Parapet/Internal Walls could obstruct the horizontal migration of water as suggested by Mr Lee.

152.  As to the reason for not including the Plaintiff’s Roof in the Flooding Test, Dr Lam answered that it was based on the agreement of the experts.[49] They agreed that the Flooding Test should be performed at the start only on the Common Roof, so as to prevent any confusion as to where the leakage came from if the Plaintiff’s Roof was tested at the same time. He and Mr Mak had also reached a consensus that another flooding test on the Plaintiff’s Roof could be conducted if either one of them was not satisfied with the results obtained from the Common Roof. Dr Lam was satisfied with the results he gained in the Flooding Test, hence there was no such request from him. Although Mr Mak was dissatisfied, he did not express any desire to test the Plaintiff’s Roof. Dr Lam disagreed that, in the absence of any test conducted on the Plaintiff’s Roof, the possibility that the leakage came from the plaintiff’s Roof could not be eliminated; he asserted that such possibility was too remote, and the results of the Flooding Test were sufficient to indicate where the leakage originated from.

153.  Dr Lam had no quarrel with Mr Mak’s observation during the 2^nd Joint Expert Inspection that conditions at the concerned areas within the Plaintiff’s Flats had not further deteriorated since the 1^st Joint Expert Inspection, in spite of the heavy rainfalls from June to September 2017. That being said, Dr Lam could not eliminate the possibility that water was stored up inside the materials, as visual inspection could not reveal the same. Hence Mr Mak’s comment, taking it to the highest, was superficial.

154.  Turning to the DR, Dr Lam agreed that the southwest side of it was located beneath and close to the Plaintiff’s Roof, roughly 1-2 metres between them. He also agreed that at the junction between the end of the Common Corridor and the Plaintiff’s Roof,[50] one could see that the ground level of the latter was lower than that of the former. Dr Lam estimated that the difference in height was about 10-20 mm. Due to such feature, Mr Lee suggested that when it rained, the water would flow from the Common Corridor onto the Plaintiff’s Roof, putting the latter in graver risk of water damage and leakage. Dr Lam rebuffed the idea, saying that it had no relevance to the question of waterproofing. The water would be collected everywhere when it rained, hence with or without the height difference, rainwater would be collected at the Plaintiff’s Roof.

155.  Dr Lam clarified that he had made no suggestion that the repair works at the Common Corridor had caused water to leak into the DR. What he meant was that the repair was conducted at the original leaking spot (see §93 above).

156.  Regarding the SH, Dr Lam confirmed that the Flooding Test did not cover Lam’s Locations 5 and 6, hence one could not rely on it to tell the source of the water leakage. Despite so, he did not share the view of Mr Lee that no test was conducted at those Lam’s Locations at all. Tests and Measurements were done by EMM and infra-red thermography.

157.  Mr Lee took a break from this topic and turned his focus on the Tests and Measurements. He suggested that the purpose for the same was to detect the moisture at a certain location, and the measurements themselves could not determine the source or cause of the water seepage. This was accepted by Dr Lam, with the additional comment that the measurements were used by the experts to conduct their analysis and determine the cause.

158.  Mr Lee’s ensuing proposition that there was no basis for identifying the cause of the water leakage at the SH with just the measurements was considered a misconception by Dr Lam. Dr Lam expounded that when one talked about the source of water seepage, it meant where the water came from. And for Locations 5 and 6, rainwater was the sole source and no test was required to validate this.

159.  The follow-up questions raised by Mr Lee were accepted by Dr Lam, namely that the water seepage at Locations 5 and 6 could come from the roof of the SH, the Plaintiff’s Roof or the walls of the SH. Mr Lee challenged that Dr Lam had failed to conduct any test to identify the sole leakage point, which was refuted by Dr Lam with reference to his comments in the JER (see §127(7) above). Nevertheless, he conceded that he could not single out the most likely cause of water seepage.

160.  When Mr Lee persisted in his point about no test was being performed at the SH, I interposed with the question as to whether this would be necessary when Mr Mak had expressly agreed with Dr Lam’s views. Mr Lee replied that this was a crucial point, citing that there was no test conducted at the external wall of the STOR, and Dr Lam had to identify the cause by deduction. I am baffled by this reply; I do not understand how the condition at the STOR could be compared with that at the SH.

161.  The STOR and DC received much attention from Mr Lee in his cross-examination of Dr Lam. There was no dispute from Dr Lam that the Flooding Test on the Common Roof did not extend to the part where the Drain was situated. He agreed that there was a small door at the top of the DC inside the STOR[51], and when the door was opened, one could see a pipe located inside it. [52] There was no denial from him that the pipe could be the downpipe he described which was connected to the Drain at the Common Roof, or some other pipe, but the best estimation was that it was the former. He disagreed that it was a vent pipe connected to the refuse chute as Mr Mak suggested in the JER. In support of his view, Dr Lam first referred to where the pipe was located. On the 33/F, it was inside the STOR (and hidden in the DC), whereas on the 34/F, the pipe was embedded inside the tiled wall of Bathroom 4 adjacent to its door (see Plan 2).[53] He remarked that there was no use of a refuse chute and therefore a vent pipe at these locations. Hypothetically, if the vent pipe of the refuse chute was connected to the pipe inside the DC, and there was water leakage from the same, it would bring out not only water but the foul smell from the refuse chute, and there would also be colours on the affected walls inside the STOR. Dr Lam therefore eliminated such possibility from his consideration.

162.  Dr Lam conceded that he did not inspect the downpipe by conducting any test on it. Despite so, he emphasised that the source was rainwater, therefore the possibility that the water seepage at DC and STOR was caused by water escaping from the downpipe.

163.  On the chance that the seepage at DC and the STOR could come from Bathroom 4, Dr Lam maintained his view that the latter was not in use before, during and after the Flooding Test. He had checked and confirmed the bathtub inside Bathroom 4 had not been used for quite some time. In fact, as informed by the Filipino maid of the family, Bathroom 4 had been used as a storage.[54] Amid water was still supplied to Bathroom 4, and with the water closet and the water basin inside remained usable, Dr Lam opined that the likelihood of Bathroom 4 causing the water leakage at DC and STOR was very low. He reasoned that there were days when the DC was dry (i.e. on Day 0, Day 1 and Day 2), which would be impossible if the water closet and/or the water basin were regularly used by the family.

164.  Mr Lee then brought Dr Lam to the water marks seen on the wooden floor just outside the door of Bathroom 4.[55] Mr Lee suggested that the same were clear indication that the water came from Bathroom 4 rather than the Drain on the Common Roof and via the downpipe. Dr Lam answered in the negative. He explained that water would sometimes run in a mysterious way, so it might not be the case that the water marks would appear around the wall of Bathroom 4 where the downpipe was embedded.

165.  The protimeter issue was the next dish served to Dr Lam. Mr Lee referred to the tables appended to the Guide to illustrate that both ERM and ECM are reliable and applicable when used to conduct measurements at the roof, wall and floor made of concrete.[56] Notwithstanding what the Guide had stated, and there is no literature to support his view, Dr Lam persevered with his crusade to advocate how inferior the ECM is. He repeated the reason that he had provided in the JER (see §130 above) but this time he also used the DC, which was made of thin boards (less than 20 mm), to illustrate how the ECM was not suitable for measuring the same. He also repeated on the inaccuracy of readings using the ECM (see §136 above). On this point, Dr Lam rejected Mr Lee’s recommendation that ECM Moisture Table is not applicable to ECM. Dr Lam emphasised that the same came from the Specification set for the brand and model of ECM which was used by Mr Mak.

166.  Relying on Mr Mak’s comments on the history of ERM[57], Mr Lee suggested that the same should be used on timber rather than concrete. This was rejected by Dr Lam. He also disagreed with the proposition that EMM would require corrections when used on different materials,[58] as he had used a control point for comparison with readings from other locations.

167.  Mr Lee made further suggestions that the results obtained by Dr Lam using ERM to conduct his Tests and Measurements were inaccurate. With no disrespect to Mr Lee, I think it is redundant to set them out in this judgment, as Mr Mak had, at trial, confirmed the reliability of the readings recorded by Dr Lam (see §185 below).

His evidence under re-examination

168.  Dr Lam was referred to Lam’s Solo Report, where he indicated with blue stars on a photograph and a floor plan of the Common Roof (see Plan 3 for their whereabouts; defined as Blue Stars 1, 2 and 3 for clarity). He confirmed that these were the spots where he found high moisture content at the ceiling of EDB, and they were located quite far away from the Parapet Wall. He estimated that Blue Star 3 was the closest spot to the Parapet Wall, approximately 3-4 metres between them.[59] Dr Lam added that, if the water came from the Plaintiff’s Roof as suggested by Mr Lee, there would be marks appearing on the ceiling of EDB along the tracks of water migrating to Blue Stars 1 to 3.

169.  Upon the request of Mr Chiu, Dr Lam marked on the floor plan the spot where the paint was peeled off on the ceiling of DR, and the location where repair was done near the Common Corridor. These were marked as “Leakage Point” and “Repair Point” on Plans 2 and 3 respectively.

170.  As to the SH, Dr Lam’s attention was brought to some photographs contained in Lam’s Solo Report. Specifically, a photograph depicting the exterior of the cylindrical part of the SH on the Plaintiff’s Roof was shown to him.[60] It could be seen from it that there was a bulge on the wall of the same. Dr Lam supplemented that this being the indication that the water came from the top of the SH, leading to the water bulging out thereat (see §127(7) above). He clarified that this was the second possibility that he had highlighted in the JER, and it was actually the same as the third possibility as suggested by Mr Mak. Dr Lam agreed that this was a structural defect of the SH’s wall.

171.  Mr Chiu invited Dr Lam to elaborate on the first possibility, i.e. ineffective waterproofing at the upturn of the Plaintiff’s Roof. What he meant, Dr Lam explained, was that when waterproofing membrane was laid on the roof, the same would also cover the edge of the ground and turned upward to any vertical structure, in this case the external wall of the SH. In other words, the waterproofing membrane would cover the bottom of the wall, hence creating some protection against ingress of water from that point. The height of the upturn would normally be around one foot, i.e. 300 mm up the wall.

EVIDENCE OF MAR MAK

172.  Mr Mak was tendered for cross-examination immediately after he had adopted Mak’s Solo Report and JER as his evidence-in-chief.

173.  Mr Chiu’s first point of challenge was Mr Mak’s experiences as expert witness. To make a long story short, he acted as single expert witness in 3 previous court cases (the action numbers were not provided in his Curriculum Vitae). He could not recall his evidence being contested, nor could he recollect whether his evidence was accepted by the court as he left immediately after his testimony was completed. His clients did not report to him the results of the cases. Mr Mak admitted no judgment could be found to show that his evidence as an expert was accepted by the court.

174.  Mr Mak accepted that, based on the Guide, ECM is not a protimeter. For the first time, Mr Mak denied that the ECM he used was CEM model DT-128M. As such, he doubted the applicability of the ECM Moisture Table.

175.  As to his method of calibration, since it was done in the air, Mr Mak accepted that the temperatures at the time of calibration on Day 1 to Day 8 should be recorded down, but he had not done so. He agreed that the temperatures and humidity varied on the days when the calibration was done before Tests and Measurements, but since they were not recorded, it was unknown whether the same would have any effect on the readings. However, he disagreed that the “0%” reading on each day would be different, thereby rendering the results unreliable.

176.  Regarding the test on a piece of dry paper (see §120 above), Mr Mak clarified that the same was not simply on the paper, but the desk where the paper was placed on. This would satisfy the minimum testing depth of 20 mm for ECM.

177.  Mr Mak confirmed that when he was conducting the Tests and Measurements on Mak’s Location 7, he selected his checking points randomly. There was no grid point set by Dr Lam at that location. Mr Mak did not record down the random points that he adopted thereon, although he said he would check the same random points on other days when Tests and Measurements were performed. Such approach was not limited to Mak’s Location 7, but extended to other Lam’s Locations when he performed the Tests and Measurements beyond the grids points set up by Dr Lam.

178.  At trial, Mr Mak confessed that the use of random points and venturing out from the grids points set by Dr Lam were done on his own initiative, and without informing Dr Lam of the same. He also found it unnecessary to keep a record of the random points that he had measured, say on Day 0, because on the days that followed, he would adopt different random points for measurements so long as they were around Lam’s Locations.

179.  As to the Tests and Measurements, Mr Mak reiterated that he only took one measurement per spot. Nevertheless, he later on uttered that in order to get the mean of the moisture level at each spot, numerous measurements would be required. He added that different spots would produce different moisture level, as they might contain diverse material compositions, even though those spots sat on the same piece of concrete ceiling. Hence there was the need to perform the Tests and Measurements at various spots within the same Lam’s Locations. Ensuing on this, Mr Chiu suggested that it actually lent importance on the usage of the same spots for Tests and Measurements on each day so as to achieve consistency in the results. Mr Mak agreed with this but stressed that it was unnecessary.

180.  Mr Mak agreed that the reading of 98% at Lam’s Location 4 on Day 8 reflected that the spot was very wet. When he was asked why then he concluded there was no water leakage at the EDB, Mr Mak answered that he did not rely on any data when he made the said conclusion.[61] I followed-up on this by asking what formed the bases for his conclusion at the earlier part of Mak’ Solo Report where he said there was slight increase of moisture at EDB on Day 8,[62] Mr Mak simply replied that he did rely on the data for such conclusion. Unable to understand how he reached such conclusion with the 98% wetness reading, I queried if that indicated there was leakage at that point. Mr Mak disagreed, repeating his view that the Flooding Test was done on Day 1, and any leakage would have surfaced immediately or almost immediately (like on Day 2). He compared the situation with a hole in a water-containing plastic bag. The leakage would be instantaneous. The 98% wetness reading, he expounded, could stem from a metal nail which was used to secure the false ceiling with the concrete or timber frame; the metal nail would attract more moisture, hence the higher reading. Mr Mak added that as it had rained on 12 and 13 November 2017, it could have caused the metal nail to absorb the humidity in the air leading to the higher moisture reading.

181.  Mr Mak denied that he gave no specification as to what reading would be considered high in Mak’s Solo Report. Mr Mak said he had already explained, that for any reading above 47%, it would mean there was higher moisture content; and it was considered “wet” if the reading was close to 100%. In a nutshell, Mr Mak said he found there were high moisture content in Lam’s Location 4, but not to the extent of “wet”. This led to his conclusion that there was no continuing leakage therein. When Mr Chiu pressed on with the question as to why 98% reading was regarded as mere “slight increase of moisture” in his dictionary, Mr Mak refuted that the said remark was referring to the general condition in the EDB, i.e. Lam’s Locations 1 to 4, not just on the latter.

182.  Unimpressed with the above answers, Mr Chiu besought an answer from Mr Mak as to what fell within his meaning of slight increment, and how he would interpret a reading of over 60%. Mr Mak responded that only if there were many points within the same location came back with readings of 90% or above would he consider there was leakage at that location. Interestingly, Mr Mak supplemented that experts would not use statistic to find water leakage, in spite of the extensive Tests and Measurements conducted, and results from the same being recorded and studied. Mr Mak said the statistics were aimed solely to provide easier understanding for the readers.

183.  Exclusively for Lam’s Location 4, since the reading of 98% at one point was insufficient to justify a finding of leakage, I asked Mr Mak what readings must be present to change his mind. He answered, only if it could be shown that areas surrounding the spot where 98% reading was recorded also came back with readings of high moisture contents. This would show, Mr Mak explained, that the water coming from the 98% spot spread out to its encompassing areas, thus fortifying the possibility that there was continuous water leakage.

184.  Seeing from his record on Lam’s Location 4 on Day 8 that there were two other spots with readings of 64.7% and 63.1%,[63] and adopting the standard he referred to at §§ 119 and 181 of this judgment, I inquired whether this would be an indication of the “spread-out” that he mentioned in the preceding paragraph of this judgment. When Mr Mak said he had no way to know whether the said two spots were close to the spot of 98% reading, I felt much deflated. I was amazed when he used this to justify his request for further investigation into the water damage seen in the EDB (i.e. whether it could have been caused by water migrating horizontally from the Plaintiff’s Roof). When I suggested to Mr Mak, if he had recorded down the spots that he had conducted his Tests and Measurements, including the grid and random points, he would already have the answer; he agreed.

185.  At this juncture, Mr Mak agreed with Mr Chiu’s suggestion that the readings obtained by Dr Lam were reliable.

186.  Mr Mak gave us another surprise when Mr Chiu commented that we would never know whether the 98% reading was really due to there being a metal nail. Hearing this, Mr Mak dramatically revealed that, all along, he had kept his own archive as to where the readings were taken, in the form of some photographs.

187.  As to Stars 1 to 3, Mr Mak refuted Mr Chiu’s suggestion that Star 3 was about 4 metres away from the Parapet Wall. Mr Mak said that the distance should be 2.5 metres only. In the midst of his response, he also said that Lam’s Location 1 should be closest to the Parapet Wall.

188.  Mr Mak could not eliminate the possibility of the water damage seen in EDB being the product of water seepage from the Plaintiff’s Roof, since no test was performed thereon. He had in the past seen water travelling horizontally for up to 2.5 metres, hence the possibility that the high moisture at Star 3 could be coming from the Plaintiff’s Roof. Mr Mak remarked that the Parapet Wall provided no obstruction to the horizontal movement of water from the Plaintiff’s Roof to the Common Roof, as the same was just laid on the surface of the roof without going through the concrete slab. He also opined that works on the Plaintiff’s Roof could have impact on the conditions of EDB’s ceiling, if the waterproofing membrane of the former was damaged.

189.  Regarding the SH, Mr Mak agreed that Dr Lam’s second possible cause was the same as his third possible cause (see §127(7) above). As to Lam’s Location 6, water leakage at the internal walls of SH, Mr Mak could not say whether it was caused by the defective waterproofing membrane at the upturn of the Plaintiff’s Roof with the wall of SH. The upturn, according to his knowledge, would cover up to a height of 150 mm on the wall. He therefore considered water coming in from the external walls of SH as the more likely cause. Nevertheless, water ingress from the external wall of the cylindrical part of the SH was equally unattractive, as the bulge seen on it was at the top end of the structure. Hence the chance of it causing the damage at the bottom of the internal walls of SH was slim. Conversely, he considered the grey area seen at the skirt of the external wall of SH as the probable spot of water ingress.[64]

190.  As to DR, Mr Mak clarified that it was situated directly beneath Lift Motor Room 1. The water damage was located at the middle of DR. Although he agreed that the area which was repaired on the Common Corridor would be very wet when it rained, as there was a downpipe directly above it, there was no information before him as to whether that was the cause of water leakage into DR. It was impossible for him to say whether the repair on that part of the Common Roof brought the leakage to a halt, as the extent of the repair remained a mystery.

191.  Mr Mak confirmed his view in Mak’s Solo Report that there was water leakage at STOR and DC, and the same was continuous. However, the cause of it could not be ascertained. The water could come from Bathroom 4 or via the Drain in a way as suggested by Dr Lam. For the latter, the preliminary question was whether it was indeed the downpipe of the Drain which was located inside the DC, when the plans showed there were the vent pipe of the refuse chute and some other pipes within the vicinity. In light of Dr Lam’s view had long been revealed, Mr Chiu questioned why Mr Mak did not investigate what pipe lied inside the DC; this was left unanswered by Mr Mak.

192.  For alleged leakage from Bathroom 4, Mr Mak agreed that the moisture contents at STOR and DC on Day 0 to Day 2 were not as high as those recorded on Day 8. He said that there was a significant increase in the moisture content on Day 8, and it could be caused by the rainfalls on 12 and 13 November 2017. That being said, Mr Mak emphasised that the possibility of leakage coming from Bathroom 4 could not be disregarded, when the water closet and water basin could still be used.

193.  Mr Mak refused to say whether he agreed with Dr Lam’s proposed methods of repair, recommending Mr Chiu to read the JER to find the answer. His answer to the question whether new waterproofing membranes should be laid on the whole roof was simply this: new membranes would be required. However, he finally agreed that there should not be partial replacement, as there could be leakage from the interface between the new and old membranes.

Evidence under re-examination

194.  Based on his estimation, Mr Mak said Location 1 inside EDB was about 2 metres away from the Parapet Wall.

195.  As to the grey area at the skirt of the external wall of SH (see §189 above), Mr Mak said something had been hacked off from the location, therefore the grey contents were revealed. When asked what kind of work would require such procedure, he replied that there could be many, for examples re-tiling, re-roofing and etcetera. What could be certain is that it could not be a finished state of the external wall. He supplemented that, in order to find the upturn of waterproofing membrane, one would have to hack into the original concrete wall. Mr Mak could not say for sure whether the work that was captured in the photograph was to replace the upturn membrane, but it was possible.

196.  Having reproduced the salient evidence from Dr Huan, Dr Lam and Mr Mak, I will now provide my analysis below.

ANALYSIS

197.  Both counsel have cited numerous authorities in support of their respective submissions and to undermine the opposition’s. I do not intend to set them out in detail. Where necessary, reference to them will be made whilst I render my views. That being said, I have given myself the obligatory reminder there is no presumption that the water leakage was necessarily cause by the flat (or in our case the roof) above, and the Plaintiff bears the burden of proof to establish the source of water on a balance of probabilities. It is not for the 1^st and 2^nd Defendants to find out or identify the correct source of water leakage or to prove that its origin did not come from the common parts.[65]

198.  Apart from the above, I also note that the duties imposed on incorporated owners and managers under a deed of mutual covenant are not absolute duties.[66] The overall duty imposed is one of proper management, which entails doing all that is reasonably required of a manager in the circumstances. Furthermore, despite the duties prescribed under section 18(1) of the BMO, the incorporated owners do not provide an insurance to the extent that if some part of the building becomes in disrepair, the same would be liable automatically. Liability may arise if there was fault, and if, having been made aware of a defect which requires remedy, the incorporated owners failed to take appropriate steps.^[67] The building management duties under common law, e.g. in the tort of negligence, is no wider than those under the deed of mutual covenant.^[68]

199.  In the sections below, I will adopt the deduction method; by excluding some issues, questions and evidence from my consideration, in hope of focusing on the heart of the matter.

The infra-red thermography results

200.  Despite infra-red thermography was performed by Fugro, neither expert placed much reliance on the results. Although the same showed no moisture at other Lam’s Locations save the STOR and DC, Dr Lam had questioned the reliability of the same (see §144 above). Likewise, as I have highlighted in this judgment (see §112 above), Mr Mak was against the use of the infra-red thermography since the very beginning, and remained critical to the results, doubting their accuracy and reliability despite the same are largely favourable to his client’s case.

201.  For these reasons, and notwithstanding Mr Lee’s enthusiastic reliance on them, I shall disregard the results of the infra-red thermography. It follows that Mr Mak’s criticisms under the readings issue (see §128 above) requires no consideration from this court. It is redundant for me to rule on whether Dr Lam should have arranged for infra-red thermography to be taken at his control point, when the results from infra-red thermography conducted by Fugro are considered to be inaccurate and unreliable by the experts.

Unpleaded points

202.  In Kwok Chin Wing v 21 Holdings Ltd,^[69] Ma CJ rehearsed on the importance of pleadings:-

“21. It should by now really be quite unnecessary to issue yet another reminder on the rationale behind pleadings. The basic objective is fairly and precisely to inform the other party or parties in the litigation of the stance of the pleading party (in other words, that party’s case) so that proper preparation is made possible, and to ensure that time and effort are not expended unnecessarily on other issues:- Wing Hang Bank Limited v Crystal Jet International Limited. It is the pleadings that will define the issues in a trial and dictate the course of proceedings both before and at trial. Where witnesses are involved, it will be the pleaded issues that define the scope of the evidence, and not the other way round. In other words, it will not be acceptable for unpleaded issues to be raised out of the evidence which is to be or has been adduced. As the Court of Appeal remarked in Wing Hang Bank Limited v Crystal Jet International Limited:-

“(2) In a trial, particularly where evidence is given by witnesses, it becomes extremely important that each side knows exactly what are the live issues. Where issues are sought to be introduced that have not been adequately or properly pleaded, amendments must be sought unless the consent of the other party or parties has been obtained. It will simply not do for unpleaded issues to be ‘slipped in’ when evidence is being given in the hope that the other side is not sufficiently alert to object.” (emphasis added)

203.  In another Court of Final Appeal judgment,^[70] Ribeiro PJ reminded litigants on the need to raise all issues in their pleadings:-

“30. The fact that the plaintiff was unprepared to argue an essential aspect of its unpleaded alternative indicates just how unacceptable it was to allow this purported alternative to be run. A party must raise all the issues he wishes to raise to be dealt with at the trial. Parties are not entitled to have issues recently thought up dealt with separately and piecemeal. The other party is entitled to know from a clear pleading what is the entire case he has to meet so that he can decide whether particulars should be sought; how he should plead in response; what discovery he is entitled to; what evidence he should adduce to meet it; and what points of law should be taken. Notions like “the entire quantity of the mud dredged from the CT9 project” might be studded with arguable questions as to how such quantity should be ascertained dependent on the evidence. If there was room for exceptions regarding bad weather or anything else, the scope and effect of such exceptions could no doubt throw up factual and legal questions.

31. Where a late attempt is made to introduce a new case, it is doubly important that the other side should have a clearly pleaded draft amendment so that proper consideration can be given as to whether objections should properly be made to such amendment and whether an adjournment should be sought.

……

34. Pleadings are not mere formalities. They impose a necessary discipline and are fundamental to enabling every procedural facet of the adversarial system to operate fairly.” (emphasis added)

204.  Mr Chiu, in his closing submissions, heavily criticised the 1^st and 2^nd Defendants for not adhering to these rules.  He highlighted the allegations put forth by them that were never pleaded:-

(1) The alleged works on the Plaintiff’s Roof undertaken by Argent (see §60 above).

(2) The water leakage at EDB was caused by ingress of water from the Plaintiff’s Roof, which then travelled horizontally to the ceiling of EDB.

(3) Leakage found at the STOR and DC was caused by the bathroom pipes of Bathroom 4.

(4) The water leakage at DR was caused by ingress of water from the Plaintiff’s Roof.

205.  I agree with Mr Chiu that the Plaintiff suffered prejudice when these allegations were either hinted in Mak’s Solo Report or raised by Mr Lee at the trial. As I have said at the very beginning of this judgment, the 1^st and 2^nd Defendants’ pleaded stance is to put the Plaintiff to strict proof on the essential allegations. But by making these suggestions, the 1^st and 2^nd Defendants are no longer taking a passive approach (whilst retaining the right to challenge on Dr Lam’s Tests and Measurements and the methods he adopted in reaching his conclusion, and the conclusion itself); conversely, they are putting forward some very positive cases. If these cases were pleaded clearly in the defence, they would definitely become issues in this case which entailed answers from the Plaintiff. In the quest for these answers, for example, the Flooding Test should be extended to the Plaintiff’s Roof, and extensive inspection of the pipes at Bathroom 4 could have been conducted. Evidence as to whether there was any work performed on the Plaintiff’s Roof by Argent apart from the alleviation works in 2013 (see §30 of this judgment), if so what, when, where and how the work was performed, could have been adduced by the Plaintiff.

206.  In particular, the suggestion of water ingress at the Plaintiff’s Roof and travelling horizontally to the ceiling of EDB did not find its way to Mak’s Solo Report and the JER. Neither did the suggestion of water ingress at the Plaintiff’s Roof causing water leakage to DR appeared in Mak’s Solo Report and the JER. They appeared out of the blue during cross-examination of Dr Lam. Mr Lee did not even bother to cover this with Mr Mak during the in-chief stage. His evidence on these topics came only during Mr Chiu’s cross-examination. Moreover, if Mr Mak was convinced that this would be a probable cause of leakage in EDB and DR, he should have requested for the Flooding Test to be extended to the Plaintiff’s Roof. He had every right to do so under the consensus reached between the experts (see §152 of this judgment; the said consensus was not disputed by Mr Mak at trial) and in compliance with the court’s direction.[71] He never did.

207.  Apart from the above, information about the alleged work performed by Argent could have come from the 1^st and 2^nd Defendants, as entry of workers from Argent into the Estate and the purpose for the same must have been informed to the staff of the 2^nd Defendant and likely recorded in the occurrence book. It is also highly possible that before they could commence any repair or maintenance of the Plaintiff’s Roof permission from the 2^nd Defendant would be required. Armed with such information, there is no lack of bases for the 1^st and 2^nd Defendants to put forward a positive case in their defence.

208.  For these reasons, it is wrong and unfair for me to consider and rely on these allegations to cast a negative light on the Plaintiff’s case.

209.  Assuming I am wrong on this, I shall briefly deal with them below.

210.  First, regarding the alleged works conducted by Argent on Plaintiff’s Roof, I shall repeat there is no evidence on what, when, where and how the work was performed, save for the urgent alleviation works performed in 2013. Dr Huan was pressed by Mr Lee to give his answers on these; Dr Huan’s unimpressive showing whilst doing so is understandable, given the element of surprise and the fact that he had to recollect what happened, if anything of the sort actually happened, 3 years ago in 2016.

211.  I have also considered whether it was the alleviation works in 2013 conducted by Argent which caused the leakage, and based on the evidence before me, I think it is unlikely. Dr Huan said the same was warranted because water leakage had appeared, not the other way around. There is nothing to contradict what he said. And at the material time, the Renovation Works were on-going. If the Renovation Works had caused vibration to Tower 2, then based on Mr Mak’s opinion (see §229 below), the same could lead to cracks on the concrete slab of the Common Roof and Plaintiff’s Roof, exposing the vulnerable waterproofing membrane embedded thereunder. I am not saying that the water leakage in 2013 was caused by the Renovation Works, but blaming the water leakage in 2016 on the Argent’s work in 2013 against such background is chronologically improbable.

212.  As to the point about water travelling horizontally from the Plaintiff’s Roof to the ceiling of EDB, both experts agreed on its possibility. However, whether this was really what happened in our case still require more answers. For example, were there indeed cracks in the concrete slab on Plaintiff’s Roof as suggested by Mr Mak? If so, did the cracks extend to the Common Roof directly above EDB? Would the Parapet Wall obstruct such migration? Why was there no water mark seen on the ceilings directly beneath the Common and the Plaintiff’s Roofs which might show the tracks of water migration into the EDB? And assuming Mr Mak was right that the water could horizontally migrate for up to 2.5 metres, hence the high level of moisture found at Star 3, then what about the moisture found at Stars 1 and 2? Were these 2 spots more than 2.5 metres away from the Parapet Walls? If so, how could cracks at the Plaintiff’s Roof brought about them? Moreover, Mr Mak’s explanation was that Star 3 was about 2.5 metres away from the Parapet Wall, and water could travel horizontally for 2.5 metres. If this was correct, would that mean the water ingress was at the Parapet Wall, or at the Common Roof side or Plaintiff’s Roof side of it? For water ingress to the Plaintiff’s Roof, it would exceed the distance of 2.5 metres. These questions created doubts not on the Plaintiff’s case, but the proposition itself.

213.  Regarding the suggestion that water leakage found at the STOR and DC originated from the bathroom pipes of Bathroom 4, there is not much debate that the same was rarely used albeit water was still supplied to it. As Bathroom 4 is located inside the SR, and with lavatories inside every bedroom on 34/F of the Plaintiff’s Flat, rarity of its use is fathomable. Photograph showing mattresses, luggage and board stored therein lends further support to it. And if there was leakage from the pipes of the water closet, it could be foul water that seeped into the STOR and DC, and predictably the STOR would be filled with dreadful smell. None of the experts has reported on this being the case.

214.  In addition, Dr Lam’s records showed that the STOR and DC had higher moisture levels as compared to other Lam’s Locations on Day 0, with slight increase on Day 1. However, the same fell generally and slightly on Day 2. Overall, the moisture content was maintained at a stable level during these 3 days, again supporting the Plaintiff’s case that Bathroom 4 was unused. Of course, one could argue that there was significant increase in the moisture level on Day 8, and rely on the same to speculate that Bathroom 4 had been used between Day 3 and Day 8, but this is a speculation and nothing more.

215.  What is certain, however, is that there were significant rainfalls on 12 and 13 November 2017, just 2 to 3 days before Day 8. This gave rise to Dr Lam’s opinion that this was the cause of the leakages found at the STOR and DC on Day 8. One would expect, if the rainfalls could cause damage to the DC and STOR, some damage could be spotted at Bathroom 4. This might be the case, as one could see that there were water marks on the floor tiles just outside its entrance. Mr Lee argued otherwise, relying on this to support that the water leakage found at STOR and DC came from Bathroom 4. I do not share the same confidence. The water marks were close enough to the duct chamber inside Bathroom 4. From the photographs[72], the walls of the duct chamber and floor tiles inside Bathroom 4 were white in colour. Water could have spread to the floor encompassing the duct chamber therein or on the walls of the same but veiled by the white tiles. Moreover, water damage could be seen at the ceiling of the STOR encompassing the DC. The area sits directly underneath the floor slab of Bathroom 4 surrounding the duct chamber located inside it.

216.  Overall, I am not persuaded that the leakage found at the STOR and DC came from the pipes of Bathroom 4.

Mr Mak’s evidence

217.  I am at my wit’s end in understanding the method he adopted in the Tests and Measurements, if there was. I do not follow his reason for using random points when performing the Tests and Measurements, deliberately venturing out of the grid points established by Dr Lam, and not informing Dr Lam about it (see §178 above). It is incomprehensible why the random points adopted by Mr Mak were not recorded, enabling the same random points to be checked subsequently on Day 1, Day 2 and Day 8, for the purpose of detecting any differences in their moisture level and to track the progress of water seepage after the Flooding Test. On this matter, Mr Mak said at trial he would check the same random points on the days subsequent to the Flooding Test (see §177 of this judgment). But without them being recorded, how was it possible to ensure that the same random points were tested? Mr Mak added that different points would produce different moisture level, as their material compositions could be different, even though those points sat on the same piece of concrete ceiling. This, he expounded, justified the need to perform the Tests and Measurements at various points of the same Lam’s Locations (see §179 above); this was exactly what Dr Lam did (adopting the same grid points) and Mr Mak did not (adopting unrecorded random points outside the grid points). Such contradiction between his words and acts is inexplicable.

218.  Further to the above, one would also query how it could be ascertained that reasonable or appropriate intervals were adopted by Mr Mak for these random points?[73]

219.  The problem with the lack of records of the random points that Mr Mak had performed his Tests and Measurements at was magnified when Mr Chiu and myself inquired about the point in EDB where 98% moisture level was found (see §180 above). In his answers, Mr Mak gave all sorts of reasons that could produce the high moisture level found at that spot, ranging from humidity in the air, rainfalls on 12 and 13 November 2017, and a nail inside the ceiling. In my view, all these are empty speculations when there is no information as to where exactly the spot that read 98% was. Without such information, it is impossible to check whether the same spot on Day 0, Day 1 and Day 2 already had higher level of moisture as compared to the others, or there was gradual increase of moisture at that spot which could suggest the presence of water seepage. Moreover, the said explanation from Mr Mak suggests that his measurements (and the results from them) would be affected by the humidity in the air. As such, was it not imperative to have a record of the temperature and humidity on the days when the Tests and Measurements were done? Inexplicably, Mr Mak had failed to do so.

220.  The same problem can also be illustrated when I sought clarification from Mr Mak as reproduced in §§183-184 above, leading to his concession that he should have recorded down the tested spots.

221.  Mr Mak attempted to salvage his omission by suggesting, close to the end of cross-examination, that he had actually taken photographs of the random spots that he had tested. I do not believe him. If he had, there is no reason why he refused to share the same in Maks’ Solo Report or the JER. It is equally curious for him not to mention about this when he was battered by Mr Chiu on this topic during cross-examination, not to mention when I sought consequential clarifications from him.

222.  Aside from the above, I find it mindboggling that Mr Mak only took one measurement at each spot, when he also volunteered at trial that in order to get the mean of the moisture level at each spot, numerous measurements would be required.

223.  It is most frustrating when one read Mak’s Solo Report; his conclusion that there was no water leakage (save STOR and DC) was not explained with reference to the moisture readings that he produced in appendices J and K. A reader is left in the dark as to what percentage will be regarded as wet, high moisture level, low moisture level, or dry, and therefore the grounds that Mr Mak had relied on to reach his conclusion.

224.  Dr Lam brought light to the darkness when he provided the ECM Moisture Table, which showed that many of the readings recorded by Mr Mak using the ECM actually reflected “wet” condition (see §136 above). Seeing this, one would anticipate either agreement or detailed rebuttal from Mr Mak, but he had some other ideas. Mr Mak chose to enlighten us with the history of ERM and etcetera in his lengthy reply (see §§3.6-3.13 of JER) to Dr Lam’s criticisms (see §3.2 of the JER).

225.  It was not until trial that Mr Mak pulled out a shield so impenetrable that one would wonder why it did not appear in the JER or his evidence-in-chief: Mr Mak was not using the model of ECM as suggested by Dr Lam, and the ECM Moisture Table is simply inapplicable. Interestingly, Mr Mak had decided to keep the brand and model of ECM that he used a secret. He was also determined to keep the court guessing as to what percentage of moisture level would be regarded as “wet” for his device (see §181 above). In particular, I am still left wondering how close it has to be to 100% to be regarded as “wet”. And what would the reading between 48% to 99% represent? I am still at a lost to understand why, when a reading of 98% was seen at Lam’s Location 4, he had to average out all the readings obtained in Lam’s Locations 1 to 4 and came to a conclusion that there was no continuous water leakage in the EDB. Could there be water leakage at Lam’s Location 4, but not at Lam’s Location 1 to 3? I am puzzled as to why leakage at one point should be disregarded because there was no leakage at other locations.

226.  Perhaps sensing my confusion as to the statistics, Mr Mak commented that experts would not use statistics to find water leakage, and they were produced only to provide easier understanding for the readers. I disagree. Such suggestion made all Tests and Measurements redundant. Moreover, the statistics could also be used to justify an expert’s final opinion, and this is exactly the missing link between Mr Mak’s conclusion and the statistics he produced.

227.  As to his views on the false ceiling in EDB and how it could hinder proper investigation of any water seepage problem, and the shortcomings of using grid points for the Tests and Measurements, it is most singular that Mr Mak had seemingly went along with them without giving a hint on what should have been done otherwise. For the latter, if his alternative method was to adopt unmarked random points, I would reject it.

228.  Regarding the readings issue, Mr Mak challenged on how the results obtained by Dr Lam should be read (see §134 above). His emphasis was that there were areas with higher moisture contents as compared with the others between Day 0 and Day 2. What he was trying to point out, if I understood correctly, was that the wetness was already there before the Flooding Test. However, I do not follow this logic. First, Dr Lam was using the ERM and there was the standard guide as to what score would indicate presence of water leakage. To displace this, Mr Mak must have referred to some other guides or journals in support, but the same was lacking. Second, Mr Mak had not enlightened us on what score, using the ERM, would be required to constitute high moisture content. Third, Mr Mak’s suggestion seemingly relied upon a comparison between points, not on the moisture level at a certain point. Adopting his method, what would be the result if both points increased their moisture contents together and reached the same level? Would that be taken as no seepage at both points? Once again, Mr Mak presented us with another unsolved mystery.

229.  I am also not with Mr Mak’s stance as to the Day 8 results issue. In my view, the results obtained on Day 1, Day 2 and Day 8 are equally important. Where there was immediate return of a “wet” reading on Day 1 or a slightly delayed “wet” reading on Day 2, they could be a reflection of serious cracks in the concrete slab and damage at the waterproofing membrane. Nevertheless, one should not dismiss the possibility that there was no or only small crack in the concrete slab, but once water penetrated slowly through the same and met with a waterproofing membrane which was not serving its purpose, it could take time for the seepage to show its face at the ceiling. This, to me, is common sense. In fact, it could be seen in the readings produced by Dr Lam that the level of moisture increased gradually from Day 1 to Day 8 at the EDB. There is no need for me to consider the nature of concrete, i.e. low permeability or porous substance, where neither expert provides any authority to support their respective argument.

230.  Moreover, there are a number of prerequisites that must happen in Mr Mak’s proposition. He said that concrete slab of 150 mm thickness or less are prone to cracks due to large differentiate temperature seasonal and daily cyclic changes, as well as other loading stresses and vibrations. First, Mr Mak had not provided to this court what other loading stresses and vibrations he was referring to when what we are concerned with here are the Common Roof and Plaintiff’s Roof. Second, there is no information as to the thickness of the concrete slab on the Common Roof and the Plaintiff’s Roof, hence I do not know whether it was prone to cracks. Third, I am also not enlightened as to how large the differentiate temperature seasonal and daily cyclic changes must be to bring about the cracks, and how they would affect the number and seriousness of cracks. Fourth, with seasonal temperature change being a natural phenomenon, this should have already been taken into account when the concrete slab was laid, and hence the need and importance to have a working waterproofing membrane. As a matter of fact, the key question in our case is whether the waterproofing membrane was defective. Ignoring this and focusing instead on the nature of concrete is simply putting the cart before the horse.

231.  Overall, Mr Mak’s evidence produced not clarity but puzzlement. I can appreciate that, by putting the Plaintiff to strict proof of its case, the 1^st and 2^nd Defendants are bound to challenge and doubting the findings coming from Dr Lam, but it is clear that the challenges and doubts Mr Mak created are not on the Plaintiff’s case, but on his very own opinions.

232.  For the above reasons, and applying the principles laid down by Lam J (as Lam PJ then was) in Chinachem Charitable Foundation Ltd v Chan Chun Chung,[74] I reject Mr Mak’s evidence based on the Tests and Measurements that he had performed.

233.  Before moving on to another topic, I shall mention in passing that I have considered Dr Lam’s extensive criticisms on the accuracy of ECM. With no disrespect to his interesting and forceful analysis, any ruling on this from the court is unnecessary in light of my findings above.

Issues 3A and 3B: has the source of water leakage been proved?

234.  Rejection of Mr Mak’s evidence does not automatically put over the Plaintiff’s case. Its burden to prove that there was water leakage and the source of the same is entrenched. As Mr Lee put it, the key contention is whether the source came from the Subject Common Parts or the Plaintiff’s Roof/Flat. Considering all evidence adduced by the Plaintiff, I am persuaded that it has successfully discharged the burden in showing that it was the former. I find that the source of the water leakage came from the Subject Common Parts. My reasons are provided below.

235.  Complaints of water leakage at Plaintiff’s Flat were documented since May 2016, which led to the 1^st and 2^nd Inspections. Representative of the 2^nd Defendant, Mr Li, had never disputed the presence of water leakage, and went so far as to ask the contractor to conduct the Waterproofing Works on the roof between 20 June 2016 and 9 July 2016. Unfortunately, leakage resumed in September 2016, and complaint was again lodged by Ms Daisy Wong by her email dated 6 September 2016. In his reply email of even day, there was no denial of the same by Mr Li of the 2^nd Defendant, and with the promise that the matter would be passed to Hong Dau for follow up. Interestingly, without any documented inspection by Hong Dau or the staff of the 2^nd Defendant, denial came from the 2^nd Defendant’s insurer[75] via its letter dated 30 September 2016.

236.  Pausing here, despite the lack of documentary evidence showing that water leakage at the Plaintiff’s Flat started in 2013 as alleged by Dr Huan, there is nothing to contradict his verbal evidence on this. I accept that water leakage had started in 2013, and it had stopped in 2015, but re-surfaced in May 2016. There was another halt of water leakage after the Waterproofing Works, but it lasted only until September 2016.

237.  Coming back to the water leakage since September 2016, I also note that water leakage was not a problem exclusively suffered by the Plaintiff, as Mr Ng, the Chairman of the 1^st Defendant, openly admitted in his letter dated 15 August 2018 that all Towers of the Estate suffered from the same fate, and promised to procure corrective works. The 1^st and 2^nd Defendants have not disclosed to the court whether Mr Ng had lived up to his promise on this, but if he had, the Plaintiff’s Flat was obviously not a beneficiary.

238.  What is telling from the above is that, in spite of the Renovation Works, which Mr Lee suggested and Dr Huan agreed to include repair works at the roofs (see §51 above), all Towers of the Estate continued to suffer from water leakage problems. On this point, it was also reported by Mr Ng that there was a litigation between the 1^st Defendant and Hong Dau over payment withheld by the former from the latter due to costs of outstanding defects which should be off-set. These are hints that the Renovation Works, if not being the creator of the leakage problems, did not cure the same.

239.  Returning to the Plaintiff’s case, it is supported by the findings of Dr Lam. Visual inspections revealed that there was water damage seen at the EDB, DR, STOR, DC and SH. Flooding Test conducted on the Common Roof showed that there was water leakage at the ceiling of EDB. DR was unaffected by the Flooding Test. Whilst the Flooding Test did not cover the Drain and its vicinity, leakage was found at STOR and DC on Day 8. Similarly, leakage was also found at Lam’s Location 5, i.e. on the floor level of the SH.

240.  I observe that the method adopted by Dr Lam is one conventionally adopted by the JO. Mr Mak’s attempts to undermine it has been rejected by me in the above. What is more, Mr Mak had expressly agreed at trial that the readings obtained by Dr Lam are correct. This is so notwithstanding Mr Lee’s attack on the lack of adjustment of the ERM by Dr Lam when it was used to test surfaces made of different materials as suggested in the Guide. On this point, I observe that neither expert actually took this as an issue in their respective solo report and the JER.

241.  Overall, I accept Dr Lam’s evidence. In particular, I am persuaded that there was water leakage at the ceiling of EDB. I accept and I do find that the source was rainwater seeping through the concrete slab and penetrating a defective waterproofing membrane embedded inside the floor of the Common Roof which sits directly above the EDB. There is no plumbing or concealed water pipes inside the roof slab which could have caused the leakage. For reasons stated in §212 above, I reject the 1^st and 2^nd Defendants’ proposition that the water leakage was caused by water ingress at the Plaintiff’s Roof which then migrated horizontally to the ceiling of EDB.

242.  As to the DR, there is no dispute that by the time of the Flooding Test, water leakage had stopped. This could have been cured by the repair work spotted at the Common Corridor (see §76 of this judgment), which should have occurred sometime between Dr Lam’s first visit on 5 May 2017 and the 1^st Joint Expert Inspection. Mr Mak had also accepted that the repaired spot could be very wet during rainy days, as there was a downpipe directly above it. As such, there is every reason to believe that something had been done to bring about the cessation of leakage; miracle has nothing to do with this. I do not believe it is a mere coincidence that the leakage had stopped after such work was done.

243.  At trial, Mr Lee tried to argue that the leakage point at the ceiling of the DR was close to the Plaintiff’s Roof, hence the possibility of it being the point of water ingress. I disagree. From Plans 5 and 6, the leakage point inside the DR is somewhere in-between the Common Corridor and Lift Motor Room 1. Not only is the leakage point close to the repaired spot on the Common Corridor, it is some distance away from the Plaintiff’s Roof. I shall reiterate that Mr Mak never suggested in his evidence that the leakage at DR was caused by water ingress from the Plaintiff’s Roof and migrate horizontally to DR’s ceiling.

244.  I find that the water damage at the ceiling of DR was caused by rainwater seeping through the concrete slab and penetrating a defective waterproofing membrane embedded inside the Common Corridor which sits above and close to the DR. I also find that water leakage from that spot to the ceiling of DR ceased after and due to the repair work between 5 May 2017 and the 1^st Joint Expert Inspection.

245.  Pausing here, relying simply on the above, and adopting the views of both Dr Lam and Mr Mak, this would warrant replacement of the waterproofing membrane not only over the affected area, but for the Common and Plaintiff’s Roofs, so as to avoid the possibility of faulty connection at the interface of waterproofing membranes, which could lead to water leakage thereat. Mr Lee’s submissions that any repair should be localised so as to reduce any inconveniences to other users of the Common Roof are against the experts’ united opinions. There is no evidence before me as to how other occupants of Tower 2 would be affected by the repair of both the Common and Plaintiff’s Roof, and the extent of inconvenience if any, as compared with localised repairs. I therefore reject his submissions on this.

246.  I must say the source of water leakage at the STOR and DC is most challenging to resolve. The leakage could be caused by water ingress from the external walls of Tower 2, or from the Common Roof via the Drain as suggested by Dr Lam. For the latter, Mr Mak agreed that it could have been caused by the rainfalls on 12 and 13 November 2017. Nevertheless, there is the question as to whether the downpipe from the Drain was indeed the pipe seen inside the DC. Mr Lee said it could be the vent pipe of the refuse chute, which appeared in Plans 1 and 2 (on 33/F and 34/F) and photographs 32 and 33 of Mak’s Solo Report.[76] If this was accepted, then it is unlikely that the water same from the Common Roof.

247.  In my view, the location of the Drain is close to the top of the DC for the downpipe to be contained therein. One could see from the said photographs that the Drain is located beside the top of the refuse chute. There must be a downpipe for the water to escape via the Drain. There is nothing to show where the downpipe could be found other than inside the DC. Conversely, the vent pipe seems to be totally embedded with no opening save there are pipes connected horizontally to the chamber which housed the vent pipe. In the circumstances, if water was to run down from the Common Roof to the STOR and DC, it would more likely be via the Drain, be it along the edges of it or through the defective waterproofing on the Common Roof in the vicinity of the Drain.

248.  Come what may, as I have excluded leakage from Bathroom 4 as a possible cause, what remains (i.e. the external walls or the Common Roof) are both within the Subject Common Parts.

249.  Moving on to the SH, both experts agreed that the leakage could be caused by the defects at the roof or external walls of SH, facilitating water to ingress from them. I accept their views. The readings provided by Dr Lam showed that there was no water leakage until Day 8, coinciding with the rainfalls on 12 and 13 November 2017.

250.  Mr Lee, in his submissions, tried to dissuade me by reference to the lack of testing done at that location, citing the case of Vast Team (Hong Kong) Limited v Hong Kong Marine Contractors Limited.[77] Peculiarly, it is also his submissions that after the Flooding Test, only Lam’s Location 5 was found to have high level of moisture. The latter is clearly inaccurate, as no Flooding Test was conducted at that part of the roof. Coming back to the Vast Team case, I do not see how it could advance Mr Lee’s argument under this head. The learned judge dismissed the plaintiff’s case not because there was a lack of testing done; he rejected the suggested locations where water leakage allegedly came from the defendant’s flat after considering the evidence before him. Conversely, the court in Leung Yung Chung & Anor v Chan Wing Sang & Ors[78] had accepted the views of the expert although no test was conducted, as there was factual basis from which the conclusion could be reached. Cheung J also found that whilst there was other possible cause of leakage, majority of the problem was caused by the leakage in the piping system at the flat above.

251.  There is of course the question of whether the SH, its external walls and roof, falls within the common parts of Tower 2. It is obviously not, as it situates on top of the Plaintiff’s Roof. That being said, following the definition set out in clause 19(d)(i) of the Principal Deed, the SH being a structure on the Plaintiff’s Roof does seem to fall within the jurisdiction of the 2^nd Defendant to repair, and the expenses for the same shall be borne by all owners. Mr Lee has not argued otherwise in his submissions. Neither has the 1^st and 2^nd Defendants denied this in their pleadings.

252.  Mr Lee, in his submissions, argued that where there is more than one possible cause of water leakage to a single location, it does not satisfy the standard of proof required from a claimant. I disagree. As I have held in the above, all the possible causes are within the Subject Common Parts or within the 2^nd Defendant’s jurisdiction to repair. I shall also repeat the decision in Leung Yung Chung case above.

253.  In summary, I find that there are continuing water leakages in EDB, STOR, DC and SH. There was water leakage at the DR which had been cured. All these water leakages come and/or came from the Subject Common Parts and on the Plaintiff’s Roof which is within the jurisdiction of the 2^nd Defendant to repair under clause 19(d)(i) of the Principal Deed.

Issues 1 and 2: are the 1^st and 2^nd Defendants in breach of the Principal Deed, Supplemental Deed, Management Agreement, and/or the BMO? Whether the 1^st and/or 2^nd Defendant have/has failed to maintain the Subject Common Parts in a state of good and serviceable repair?

254.  In his opening statement, Mr Lee submits that by retaining the 2^nd Defendant, a professional management company, to carry out the duties under section 18(1) of the BMO, the 1^st Defendant has discharged its duties. He further submits that the 2^nd Defendant has discharged its duties under the Management Agreement, Principal DMC and Supplemental DMC by employing a maintenance contractor to maintain the Estate and carry out necessary repair. Interestingly, Mr Lee has not revisited on this in his closing submissions.

255.  In my view, the 1^st and 2^nd Defendants had not done enough to discharge their duties, be it under section 18(1) of the BMO, Principal DMC or Supplemental DMC. My findings above clearly showed that there are defects in the waterproofing membrane embedded in the Common Roof, and the water leakages were recurrent. They had acknowledged such complaint from Dr Huan, Ms Wong and Ah Tung at least since mid-2016. It is true that there were the 1^st and 2^nd Inspections and the Waterproofing Works, they had however provided no reason why there was a lack of action after D2’s 6.9.2016 Email, when the water leakage at EDB, STOR and DC have reappeared.

256.  Based on the observation of Dr Lam, some works had been done on the Common Roof directly above EDB and the Common Corridor, the latter having the effect of stopping the leakage at the DR. There is no suggestion from the 1^st and 2^nd Defendants that the same were works conducted by the Plaintiff. Equally, there is no denial from them that the said works were conducted by their contractor, Hong Dau or others. If the latter was true, the works could point to the 1^st and 2^nd Defendants’ (or Hong Dau’s) concession that the water leakages had not been resolved in spite of the Waterproofing Works. Nevertheless, the same are not relied upon by the 1^st and 2^nd Defendants to show how they had discharged their duties regarding the leakage problems. They have not rendered any detail as to what, why, how, when and by whom the repairs were done, and the extent of the repairs. I am therefore unable to treat these repair works as actions from the 1^st and 2^nd Defendants in discharging their duties. For the same reasons, no weight will be given to the Repair Works.

257.  I find that the 1^st and 2^nd Defendants have failed to discharge their duties under the BMO, the Principal DMC and the Supplemental DMC.

258.  As to the alleged nuisance on the 1^st and 2^nd Defendants’ part, Mr Lee in his opening statement argued what the Plaintiff has pleaded falls short of a claim for common law nuisance, hence there could be no claim for loss of enjoyment. I do not quite follow Mr Lee’s submissions on this. The Plaintiff has clearly set out the duties of the 1^st and 2^nd Defendants under the BMO, Principal Deed and the Supplemental Deed (at §§5, 7 to 10 of the Re-Amended Statement of Claim), pleaded the facts leading to the breach of these duties (at §§11A to 12C of the Re-Amended Statement of Claim), and relying on the same also to a claim of nuisance against them (at §13 of the Re-Amended Statement of Claim). This is pleaded separately from the breach of statutory and contractual duties. Mr Lee has not edified me with reference to authorities and the White Book as to how nuisance must be pleaded in this case to enable reliance on this by the Plaintiff. Come what may, this is not a topic that Mr Lee has continued to pursue in his closing submissions.

259.  I have considered the case of Lam Suk Yee & Anor v The Incorporated Owners of Kam Kin Mansion^[79]:-

“155. Private nuisance is basically unlawful interference with a person’s use or enjoyment of land, or some right over, or in connection with it. Generally, the essence of nuisance is a state of affairs that is either continuance or recurrent, a condition or activity which unduly interferes with the use of enjoyment of land.”

260.  In addition, I also accept Mr Chiu’s submissions based on the ruling of Woo JA in the case of Cheung Sau Ling & Anor v Cheng Lai Chong.[80] For seepage of water to constitute nuisance at common law, the defendant must be shown to have actual or constructive knowledge that the leakage of water originated from the defendant’s property. Under this test, “knowledge” can be what the defendant actually knew, or what the defendant should have known with normal or reasonable diligence. If the defendant can be shown to have actual or constructive knowledge that the water seepage originated from the defendant’s premises, the defendant will be liable unless remedial action is taken without reasonable delay. Failure to do so will render the defendant liable for damages and to be restrained by injunction.

261.  Based on the above authorities and based on what I have said in §255 of this judgment, I find the Plaintiff’s claim against the 1^st and 2^nd Defendants for nuisance is proved.

Issue 4: Whether the Plaintiff has suffered loss and damage as pleaded, and if so, whether the 1^st and/or 2^nd Defendants are/is liable for such loss and damage and the amount thereof

262.  I will deal with the costs of repair first. Before diving into the discussions below, I shall mention in passing that Mr Lee did not cross-examine Dr Lam on the costs set out in Southern Skies’s quotation. As such, I shall not consider his submissions under this head, even though he has not actually said much.

263.  For the EDB, a lump sum of HK$52,000 is claimed based on the quotation from Southern Skies. I note from the evidence before me that the main areas of damage are limited to the ceiling, but the quotation included repairs to the floor titles and walls. I cannot see from the photographs taken by Dr Lam and Dr Huan or Argent showing that the walls suffered from discolouration or have their paint peeled-off. There is nothing to show that there is erosion of floor tiles due to water droplets falling onto them. In fact, out of the 6 items of work listed in Southern Skies’ quotation, only 1 concerned with the ceiling, with 4 items being works on the walls and floor tiles. I do not think that the Plaintiff has successfully proved that these repairs are warranted. And for the remaining item being protection for the wooden boards therein, I can appreciate that the EDB was subject to much humidity attack due to the persistent water leakage problem and the last item of work is to reinforce the wood inside the room. I will allow this to be claimed.

264.  It is most unhelpful that Southern Skies has not provided a breakdown of the costs for each item of repair under this head. Doing the best that I can, I will adopt the suggested costs of HK$14,000 by Mr Mak for the repair of the ceiling, and add another HK$6,000 for providing protection to the wooden boards in the EDB. The total awarded for the repair of EDB is therefore HK$20,000.

265.  As to the DR, a lump sum costs of HK$25,000 is claimed, covering repairs to the floor tiles, ceilings and protection to the wooden boards inside the room. Mr Mak estimated that the costs should be HK$3,000. There is however no quotation provided by him to justify his view. I also observe that he has mentioned nothing about replacement of the floor tiles, despite there being evidence to show that water droplets had been falling from the ceiling onto the floor causing erosion to the wooden floor tiles. I accept the quotation from Southern Skies on this, and award the sum of HK$25,000 as the repair costs for DR.

266.  Regarding the STOR and DC, costs of repair are quoted at HK$75,000, whilst Mr Mak countered with the sum of HK$23,500. One could see from the photographs that the extent of damage suffered at the locations are serious and the conditions are dire. Again, Mr Mak has not adduced any quotation to support his estimation. I award the sum of HK$75,000 under this head, adopting the quotation from Southern Skies.

267.  Finally, for the SH, both counsel agreed that costs for repair of the external walls and roof of the same shall be excluded if the repair works were subject to the mandatory injunction, i.e. to be performed by the 1^st and 2^nd Defendants. As to the internal walls of the SH, I note the price quoted by Southern Skies (HK$3,000) is actually lower than that estimated by Mr Mak (HK$4,000). I see no reason to reject the lower amount. I shall award HK$3,000 to the Plaintiff for this item.

268.  In summary, I award to the Plaintiff a total sum of HK$123,000 for costs of repair.

269.  For the claim of loss of enjoyment, Mr Lee queried in his opening statement as to how the Plaintiff, being a body corporate and with no individuals joined as co-plaintiffs, is entitled to the same. I have, at the first day of trial, supplemented on this point by providing to counsel a copy of the judgment of HH Judge Carlson in Formalex Limited v Abdoolally Ebrahim & Co. (HK) Ltd,[81] where the learned judge questioned how a limited company could be compensated for the physical discomfort suffered by its nominated occupant (at §§17-19). At the end of the day, the learned judge held that this type of inconvenience could not be suffered by a limited company, hence his refusal to include any element of compensation for distress and inconvenience. The learned judge then adopted the principles in Calebar Properties Limited v Stitcher[82] in considering and assessing the loss of amenity value of the flat to the tenant due to the breach of covenant by the landlord.

270.  Mr Chiu’s reply to this is the case of Hunter v Canary Wharf Ltd[83] which was not cited to and considered by HH Judge Carlson. In the Hunter case, it was held by Lord Hoffman, in a nutshell, that in the case of nuisances, productive of sensible person discomfort, the action is not for causing discomfort to the person, but for causing injury to the land. Albeit the land has not suffered sensible injury, its utility has been diminished by the existence of the nuisance, for which the possessor or occupier of the land is entitled to compensation. Relying on this, Mr Chiu submitted that by pleading loss of enjoyment, the Plaintiff is in reality seeking to recover for the loss arising from the injury to the amenity value of the Plaintiff’s Flat due to the persons upon it (i.e. Dr Huan and his family) are liable to suffer inconvenience, annoyance or illness.

271.  Be that as it may, Mr Chiu has not provided to this court any calculations under this head. The case of Larbons Limited v Kuo You Weaving Factory Ltd[84] illustrated what information would be required for the court to make an assessment of damages for loss of amenity value. The Plaintiff has adduced no evidence to establish any actual loss or damage apart from the costs of repairs. Dr Huan and his family were not joined as plaintiffs to seek any relief. In the absence of these, the court can still award nominal damages of HK$100 as recognition of the Plaintiff’s legal right being infringed[85], however, such claim is not pleaded in the Re-Amended Statement of Claim.

272.  For these reasons, I make no award for the claim for loss of enjoyment.

Issue 5: Whether the Plaintiff should be granted mandatory injunction against the 1^st and/or 2^nd Defendants, and if so, the scope of such mandatory injunction

273.  In light of the above discussions, a mandatory injunction is warranted. However, question remains as to the scope of the same. I have raised requisitions with counsel at the closing submissions stage as to the terms of the mandatory injunction, if one should be granted, in light of the various possible sources of water leakage at the STOR and DC (see §94 of this judgment), and the trial and error approach as suggested by Dr Lam (see §102 of this judgment). Counsel were invited to file supplemental submissions on this topic only.

274.  In his supplemental submissions, Mr Chiu pointed out mandatory injunction shall be granted notwithstanding that the exact cause of the water leakage to STOR and DC could not be ascertained. [86] He suggested that the terms of the order shall read as “The 1^st and/or 2^nd Defendants to effect due and effective repair to stop and rectify the water seepage problems within [time], including but not limited to the replacement of the entire waterproofing membrane on the roof of Tower 2 of the Estate, with certificate of satisfaction to be issued by an independent authorised person to be appointed by the parties with liberty to apply if the parties could not agree on the candidate”.

275.  Mr Lee opposes to the terms suggested by Mr Chiu, citing the need to have finality, proportionality[87], precision[88] and the terms shall not be wider than it is necessary[89]. He also argued that the terms of the mandatory injunction as pleaded in the Re-Amended Statement of Claim would require the 1^st and 2^nd Defendants to investigate on the source of the water leakage, which in effect would be shifting the burden from the plaintiff to the 1^st and 2^nd Defendants.

276.  In my view, a mandatory injunction requiring the 1^st and 2^nd defendants to repair the rooftop of Tower 2 by replacing the waterproofing membrane embedded therein is justified (see in particular §245 above). I see nothing disproportional about this, when both experts agreed this to be the proper course to take. And with my findings that the possible sources of water leakage in STOR and DC originated from those suggested by Dr Lam, I disagree with Mr Lee that the burden has been shifted to the 1^st and 2^nd Defendants. I agree that the terms of the mandatory injunction shall be precise, hence I will adopt the terms suggested by Mr Chiu with minor variation to include references to the relevant parts of Lam’s Solo Report. I shall also impose a deadline for completion of these works. Mr Lee estimated that 4 months will be required for repairing the waterproofing membrane over the whole Common Roof and the whole Plaintiff’s Roof. The repair of external wall to the SH and the Drain and its downpipe will take 3 months. I think some of the works could be done concurrently. I will therefore set the deadline at 150 days from the date of this judgment.

CONCLUSION

277.  I make the following order for the Plaintiff against the 1^st and 2^nd Defendants:-

(1) There be mandatory injunction to direct the 1^st and/or 2^nd Defendants to effect due and effective repair to stop and rectify the water seepage problems at the Plaintiff’s Flat within 150 days from the date hereof, including but not limited to:-

(a) the replacement of the entire waterproofing membrane on the roof of Tower 2 of the Estate;

(b) inspections and repairs to the STOR, DC, Drain and its downpipe as stated in §§6.11 and 6.12 of Lam’s Solo Report;

(c) inspections and repairs to the external walls of the SH as stated in §6.4 of Lam’s Solo Report;

with certificate of satisfaction to be issued by an independent authorised person to be appointed by the parties with liberty to apply if the parties could not agree on the candidate.

(2) The 1^st and 2^nd Defendants shall jointly or severally pay the Plaintiff costs of repair in the sum of HK$123,000.

(3) The Plaintiff’s claim for loss of enjoyment be dismissed.

278.  There be interest on the sum of HK$123,000 at judgment rate from the date of this judgment until payment.

279.  The Plaintiff is largely successful in its claim against the 1^st and 2^nd Defendants. However, minor reduction in costs shall be made to reflect on its claim for loss of enjoyment being dismissed. I think a reduction of 10% is sufficient to achieve such purpose. I will therefore make an order nisi that the 1^st and 2^nd Defendants do jointly or severally pay 90% of the Plaintiff’s costs of this action, including all costs previously reserved, and such costs to be taxed if not agreed with certificate for counsel. Such order will become absolute in the absence of any application to vary the same within 14 days from the date of handing down of this judgment.

280.  Lastly, I thank counsel for their assistance.

Floor Plan