POLYSOON INVESTMENTS LTD v. LAU MO KUN AND ANOTHER

DCCJ 1549/2018

[2022] HKDC 211

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

CIVIL ACTION NO. 1549 OF 2018

--------------------------

-------------------------

--------------------------

JUDGMENT

--------------------------

A.    BACKGROUND

1.  This is a water seepage case.

2.  At all material times, the plaintiff was and is the registered owner of Flat B1, 12^th Floor (“the Lower Flat”) of a building located in Shatin (“the Building”). 

3.  Mr Chow is a director of the plaintiff.  He together with his wife (Ms Kam) resided in the Lower Flat since 1990.  While they have emigrated to Australia since 2007, they would stay in the Lower Flat from time to time whenever they were back in Hong Kong.  When they were away, they would arrange a domestic helper to visit the Lower Flat once around every 2 weeks.

4.  The 1^st and 2^nd defendants were and are the registered owners of Flat B1, 13^th Floor of the Building (“the Upper Flat”), which was located immediately above the Lower Flat.

5.  It is undisputed that the layout of the Lower Flat and the Upper Flat was identical.  Each flat had 2 bathrooms and one of those bathrooms was an en-suite bathroom.  The en-suite bathroom in the Upper Flat (“the Upper Bathroom”) was located immediately above the en-suite bathroom in the Lower Flat (“the Lower Bathroom”).

6.  In around September 2010, it was found that plasters and concrete pieces had peeled off from several areas at the ceiling of the Lower Bathroom, and reinforced steel bars were exposed.

7.  On 15 September 2010, a complaint was made by Ms Kam’s sister to the Buildings Department/Food and Environmental Hygiene Department Joint Office 1 (Sha Tin) (“the Joint Office”).

8.  The Joint Office therefore conducted colour water tests at the drainage outlets at the Upper Bathroom on 25 October 2010. However, despite those tests, the cause of water seepage could not be ascertained.  Since the water seepage problem was persisting, the Joint Office engaged its contractor, Geotechnics & Concrete Engineering (“G & C”), to conduct further investigation.

9.  By letter dated 31 December 2010 which was sent to the address of the Lower Flat, the Joint Office informed that since the water seepage spots were found to have dried up, it was considered that the water seepage had ceased, and no further follow-up work would be done.

10.  On 20 January 2012, Ms Kam made another complaint to the Joint Office about water seepage problem at the Lower Bathroom.  In response, the Joint Office conducted similar colour water tests as mentioned above on 3 February 2012, and collected water samples at the Lower Bathroom.  However, the cause of water seepage still could not be ascertained.

11.  G & C was therefore engaged by the Joint Office again.  Investigation work was done on various dates in the period between April and July 2012.  G & C conducted, among other things, pond test on the floor of the Upper Bathroom, and also spray test to the peripheral walls of the bathtub thereat.  However, at the end of the day, the cause of the seepage could still not be ascertained.  It was concluded that leakage of the drainage was unlikely, rainwater leakage was unlikely, and seepage caused by water infiltration from the peripheral walls of the bathtub in the Upper Bathroom was unlikely.  Ms Kam was informed accordingly by the Joint Office’s letter dated 17 August 2012.

12.  Ms Kam made another complaint to the Joint Office on 15 May 2013. As the Joint Office could not ascertain the source of water seepage after conducting tests on 31 May 2013, it engaged Prudential Surveyors International Limited (“Prudential Surveyors”) to do further investigation, which was undertaken in the period between July and September 2013.  In Prudential Surveyors’ inspection report, it was stated, among other things, that:

(1)  “Condition of seepage: consistently all day long”;

(2)  “Moisture content varies equal and greater than 35 at the affected seepage area”;

(3)  There was “apparent water moisture”;

(4)  “The suspected premises is at upper floor”;

(5)  “Leakage of the drainage pipe was unlikely”;

(6)  “Fall infiltration leakage was not likely possible”;

(7)  “Wall infiltration leakage was not likely possible”;

(8)  “The source is unlikely to be rain water seepage”.

13.  The conclusion of Prudential Surveyors was that the source of water seepage was uncertain.  Ms Kam was notified of this result by Joint Office’s letter dated 20 November 2013.

14.  In around May 2014, the 1^st defendant inspected the Lower Bathroom for the first time. 

15.  In July 2014, the defendants engaged a contractor to demolish the bathtub and remove the tiles on the floor, the tiles on the wall, the water basin and the water closet of the Upper Bathroom (“the 2014 Work”).  It was the 1^st defendant’s evidence that the 2014 Work was done to ascertain whether the water seepage problem in the Lower Bathroom was really caused by the Upper Bathroom.  Upon confirmation that it was not, the 1^st defendant instructed his contractor to reinstate the Upper Bathroom.  On the other hand, Mr Chow queried why the defendants would have undertaken the 2014 Works without informing the plaintiff.

16.  On 6 June 2015, Ms Kam filed another water seepage complaint with the Joint Office, which conducted colour water test again on 10 July 2015.  By a letter dated 25 August 2015, the Joint Office informed Ms Kam that no colour water used in the test could be found in the Lower Bathroom, and that the moisture content at the affected area was less than 35%.  Hence, it was decided by the Joint Office that no further action would be taken.

17.  In August 2016, the plaintiff engaged Hong Kong Survey Limited (“HKSL”) to investigate into the water seepage problem. On 8 October 2016, HKSL issued a report (“the HKSL 2016 Report”) in which it was concluded that the water seepage problem at the Lower Bathroom was caused by:

(1)  a crack at the external wall surrounding a pipe outside the Upper Bathroom;

(2)  the damaged waterproofing membrane underneath the floor, the damaged walls and the damaged drainage pipes of the Upper Bathroom.

18.  On 19 October 2016, Ms Kam complained to the Joint Office again.  On 20 November 2016, the Joint Office conducted colour water tests at the drainage outlets at the Upper Bathroom.  According to the Joint Office’s letters dated 5 January 2017 and 6 January 2017:

(1)  No colour pigments used in the colour water tests could be found by the laboratory in the water samples collected in the Lower Bathroom;

(2)  the moisture content of the ceiling of the Lower Bathroom was over 35%;

(3)  the possibility of leakage of the drainage pipes of the Upper Bathroom could be excluded on a preliminary basis.

19.  On 18 February 2017, the management office of the Building caused a spraying test to be done at the external wall of the Upper Flat.  However, no leakage problem could be seen in the Lower Flat after the spraying test.

20.  As mentioned in the letters issued in January 2017, the Joint Office engaged G & C again for further investigation. Inspections had been held on 4 days in the period between February and April 2017.  Results and conclusions similar to those reached by Prudential Surveyors in 2013 were arrived at, namely:

(1)  “Condition of seepage: consistently all day long”;

(2)  “Moisture content readings are equal and greater than 35 at the affected seepage area”;

(3)  There was “apparent water moisture”;

(4)  “The suspected premises is at upper floor”;

(5)  “Leakage of the drainage was unlikely”;

(6)  “Seepage caused by water infiltration from the floor slab master bathroom in suspected premises was unlikely”;

(7)  “Seepage caused by water infiltration from the bathtub at master bathroom in suspected premises was unlikely”;

(8)  “Rain water leakage from building envelope was unlikely”

(9)  “The source of water seepage in master bathroom cannot be identified”.

21.  The defendants engaged a Mr Pun (a plumber) to replace a part of the concealed sewage outlet pipe connected to the toilet bowl of the Upper Bathroom and to seal a crack at the external wall on around 20 May 2017.

22.  On 17 July 2017, Ms Kam issued a letter to the 1^st defendant, and warned that if he failed to engage a professional to solve the seepage problem within 7 days, she would instruct her lawyer to take further legal action.

23.  On 19 July 2017, the 1^st defendant informed the management office of the Building that he would open up the floor of the Upper Bathroom within a week.

24.  On 31 July 2017, the 1^st defendant instructed a contractor to remove the floor tiles, the water closet, the wash basin and the tiles covering the side of the bathtub (“the 2017 Work”). Apart from not removing the bathtub and keeping the tiles covering the water supply pipes to the bathtub intact, the 2017 Work was similar to the 2014 Work.

25.  Upon the removal of the floor tiles, the 1^st defendant asked the management office to send someone to inspect the Upper Bathroom together with Ms Kam.  However, Ms Kam refused to do any inspection.  Be that as it may, the 1^st defendant insisted that the management office should send someone to do an inspection.

26.  According to a record dated 29 June 2018, the management office did send someone to do an inspection at the Upper Bathroom on 2 August 2017, and confirmed that no leakage problem could be seen at the floor.  No leakage problem or accumulation of water could be found at the drainage pipe beneath the bathtub either.

27.  On 20 September 2017, the management office caused a spraying test to be conducted by its contractor known as Fu Lam (“Fu Lam”) at the external wall of the Upper Bathroom.  According to the management office’s record dated 29 June 2018, no seepage problem could be found at the ceiling of the Lower Bathroom after the test.  However, the 1^st defendant alleged that there was water seeping into the Upper Bathroom through the location of the drainage pipe of the wash basin.

28.  On 4 October 2017, Fu Lam applied some waterproof coatings on the external wall outside the Upper Bathroom and sealed the connecting points between the sewage outlet pipes and the external wall.

29.  On 16 October 2017 and 23 October 2017, Mr Chow, together with a Mr Siu (a surveyor) of Silver Consultants & Engineering (“Silver Consultants”), inspected the Upper Bathroom.  A report dated 31 October 2017 (“Silver Consultants 2017 Report”) was subsequently issued, which concluded that the seepage problem at the Lower Bathroom was caused by the damaged drainage system and waterproofing membrane at the Upper Bathroom.  In the said report, Silver Consultants also opined that the repair costs of the Lower Flat would amount to $51,044.74.

30.  On 20 January 2018, the defendants engaged their contractor to reinstate the Upper Bathroom.  They alleged that they did not use the Upper Bathroom in the period between 31 July 2017 and late January 2018.

31.  By letter dated 12 March 2018, the Joint Office informed Ms Kam that no colour water used in the previous tests could be found during the inspection conducted at the Lower Bathroom on 10 January 2018, and that despite the carrying out of tests such as ponding test on the floor, spraying test at the wall next to the bathtub and monitoring of moisture content, the cause of the water seepage problem still could not be ascertained.

32.  HKSL issued another report on 4 January 2019 upon investigation and tests done on 8 November 2018 (“the HKSL 2018 Report”). It was concluded that the water seepage problem at the Lower Bathroom was caused by the damaged waterproofing membrane underneath the floor and at the walls next to the bathtub as well as the damaged drainage pipes of the Upper Bathroom.

33.  The plaintiff commenced legal proceedings against the defendants in the Small Claims Tribunal on 5 December 2017.  Those proceedings were subsequently withdrawn. 

34.  The present proceedings were then commenced on 18 April 2018, in which the plaintiff sought an order of injunction and damages against the defendants on the basis of the following causes of action:

(1)  Negligence;

(2)  Nuisance;

(3)  Breach of the Deed of Mutual Covenant of the Building (“the DMC”); and

(4)  Breach of section 34H of the Building Management Ordinance (Cap.344, Laws of Hong Kong).

B.    THE ISSUES

35.  Having taken into account the Agreed Statement of Issues in Dispute filed on 25 September 2020, I am of the view that the issues in the present case are as follows:

(1)  Whether there was/is water seepage to the Lower Bathroom;

(2)  Whether the water seepage was/is originated from the Upper Bathroom;

(3)  If there was/is water seepage to the Lower Bathroom, whether the defendants should be held responsible thereof; and

(4)  If the defendants are liable, what the relief should be.

C.    THE EXPERTS

36.  Pursuant to the court’s expert directions, the plaintiff engaged Ms Lau Shan La (“Ms Lau”) as its expert and the defendants instructed Mr Kan Cho Yau Kenneth (“Mr Kan”) as their expert.

37.  It is undisputed that the experts had conducted inspections and tests at the Lower Bathroom and the Upper Bathroom twice, on 20 June 2019 and 12 August 2019 respectively.  Ms Lau and her colleagues had conducted a number of tests, including:

(1)  Visual Inspection (目測法);

(2)  Infrared Scan (紅外線掃描法);

(3)  Electrical Conductivity Sensory Method (導電感應法);

(4)  Microwave Detection (微波濕度掃描法);

(5)  Flow Meter Test (流量錶測試法); and

(6)  Fluorescent Dye Test (螢光色水測試).

38.  On the other hand, Mr Kan had only conducted visual inspection, touching and tapping himself.  He did not do any other tests personally.   He accepted that all other tests conducted by Ms Lau and her colleagues had been done properly.  What he did not agree was only the interpretation of the data obtained by those tests. 

39.  Pausing here, I note that Ms Lam had, in her written closing submissions, commented that Mr Kan had only relied on the 3 methods which were referred to above as the basis of his opinion.  As I pointed out during counsel’s final submission on the last day of the trial, with respect, I hold the view that this is not a fair way to describe what Mr Kan did, because Mr Kan had made it clear at the beginning of the joint expert report that the opinion he expressed in the said report would be made on the basis of the data obtained by Ms Lau, and that all those tests were conducted in the presence of Mr Kan with his consent.

40.  When this court considers the experts’ evidence in more detail in the latter part of this Judgment, as far as those areas where the experts have come to different conclusions are concerned, I will have to take into account the reasoning provided by the experts in support so as to decide whose opinion should be accepted.  However, there may be times when the court is unable to decide which of the reasoning is more sound.  In such scenario, the court may have to take into account the reliability of the experts generally.  In this process, I will bear in mind what Lam J (as Lam PJ then was) stated in paragraphs 483 to 491 of Chinachem Charitable Foundation Ltd v Chan Chun Cheun (HCAP 8/2007, unreported, 2 February 2010).  Although his Lordship was dealing with a case in which subjective expert judgements (handwriting expert evidence) were involved, I am of the view that what he said is still instructive and applicable in the present case:

“483. […] As I observed in Best Origin Limited v Commissioner of Rating and Valuation LDGA 14 of 1998, 25 February 2008, paras. 97 to 105, one of the important criteria that the court can adopt in testing the reliability of the evidence of an expert is his impartiality and due observance of his overriding duty to the court. Though judges may not be as well qualified as experts in the areas of the latter’s expertise, we are experienced and well trained in detecting partisan and biased witnesses (both in respect of ordinary factual witnesses and expert witnesses).

484. An expert should not advance an argument or use a piece of information or data to support his opinion unless he is professionally convinced of the validity of the argument or the appropriateness of the use of that supporting material. The inclusion of something the validity of which the expert himself considered doubtful in his report inevitably undermines his credibility in the court’s assessment[1]. An independent and impartial professional expert should not resort to a tactic of putting forward some plausible arguments in favour of his client which he personally has difficulty in vouchsafing and leaving it to his counterpart to convince the court that the arguments should be rejected. In my view, such an expert has not discharged his overriding duty to the court, which is to use his own professional expertise to assist the court without regard to the exigencies of litigation.

485. Here lies the crucial distinction between an advocate and an expert witness. Even though counsel and solicitor also owes an overriding duty to the court in certain respects, the court understands that as advocates they are not impartial as they also have a duty to present the case of their respective clients. But the position of an expert witness is different. His evidence is admitted to assist the court on a subject which requires expertise he has acquired (but not the court). Therefore, what the court wishes to hear is the expert’s own independent professional opinion on the topic instead of a biased view constructed and put forward for the purpose of advancing a party’s position. Given the court’s lack of expertise on the subject which an expert gives his evidence, the strict adherence by expert to the duty of independence is important for the proper administration of justice. Whilst there might still be bona fide reasonable disagreements between two experts, the disagreements should only be based on independent professional judgments instead of being client interest driven.

486. Sometimes, the line between professional divergence in opinion and biased partisan debate may not be easy to draw. But the court is vigilant in ensuring that the integrity of the legal process would not be tainted by evidence of an expert who put a party’s interest above his professional duty to the court. If it can be shown that an expert persistently adopted a stance which he himself had obvious difficulty in sustaining, most of the time this is the hallmark of the expert’s failure to adhere to the duty of independence.

487. Further, a judge is assisted by counsel (who in turn are assisted by their own expert) at the trial. Counsel’s cross-examination of an expert witness will assist the court in forming a view as to the reliability of his evidence. Very often, the most telling indicia of the professionalism and impartiality of an expert witness is how he deals with his weakest point under cross-examination. In Best Origin,I have set out what this court expects from an expert witness when he is faced with his own mistake after he produced his report. Instead of keeping silent and hoping that the point would not be discovered, he should correct it on his own volition as soon as practicable.

488. Another acid test on the reliability of an expert witness is the way in which he deals with the arguments of his counterpart. Nowadays, the court expects expert witnesses to act responsibly and professionally in meeting the points raised by the experts on the other side. The whole point of requiring expert reports to be served or exchanged and directing meetings of experts and the preparation of joint statements/reports is to facilitate independent and frank communications between the experts in order to narrow down their differences through a dialogue on a professional level. The objective is to focus on the real issues that need to be adjudicated by the court. Unnecessary and unhelpful arguments should be trimmed down through these pre-trial procedures.

489. No matter how experienced and well qualified an expert may be, it is always possible that he misses some salient points in the preparation of his first report despite the exercise of due care and diligence. Further, with the accelerated growth and development of human knowledge, new techniques or learning may emerge. Also, especially in areas where an opinion depends a lot on subjectivity, whilst there is always scope for reasonable disagreement, every expert would appreciate that amongst the arguments he relied upon, some is of greater force than others. An impartial and responsible expert, after studying the report of his counterpart, should re-assess his own views and if there are valid points against his opinion, he should acknowledge them instead of finding other new material to salvage an exposed weakness.

490. The joint meeting is an opportunity for the experts to narrow their differences. It takes two to tango. It requires both experts to focus on the objective of the meeting and act responsibly and frankly with each other. At such meeting, an expert should bear in mind his overriding duty to the court to act independently without any fear of compromising his client’s position. Thus if his professional judgment dictates that a concession should be made in the light of arguments advanced by the other side, he should not feel inhibited from doing so due to conflicting opinion previously expressed by him in favour of his client. On matters within his expertise, an expert needs not seek instructions from his client before reaching an agreement with the other side’s expert. A self-respecting expert should not accept instructions that placed limitations on his professional judgment in the performance of his duty as an expert witness. And it is not proper for lawyers to give such instructions on behalf of his clients. In line with his duty to act independently, an expert should not be dictated by his client in respect of the substance of his expert evidence and the agreement to be reached in joint meeting.

491. Thus, instead of spending time on indiscriminant defence of one’s position, expert witnesses should give due weight to the arguments set out in their counterpart’s opinion and try to reach agreement on points which are not worthy of argument. Unfortunately, there are occasions (here I am speaking generally rather than with specific reference to what happened in this trial) where some experts jumped straight to a defensive mode instead of adopting a “step-back and look” approach in considering the other side’s arguments. In so doing, I am afraid that such expert is abandoning his impartiality and neglecting his overriding duty to the court.

492. Worse still, there are occasions where expert uses the joint meeting and reply reports as platforms for putting forward new arguments and open new fronts for debate. Confronted with such a report, the other side would retaliate by putting in further materials in the name of rebuttal. More issues are raised. A vicious cycle is perpetuated. Instead of narrowing down the differences, expert issues are proliferated. The presentation of too many (including some unnecessary) expert issues not only adds to the costs and time of a trial, it also creates a risk of diverting the court’s attention away from the central issues in a case. It is not conducive to the effective resolution of the dispute. In many instances, the proliferation of issues is the hallmark of an expert struggling to defend an indefensible position by generating new issues as smokescreen.

493. Obviously, such an approach is inconsistent with the underlying objectives under Order 1A. Even though there is no reference to the expert witness in Order 1A Rule 3, after the commencement of the rules introduced by the Civil Justice Reform, an expert giving evidence in court has to observe the Code of Conduct in Appendix D, see Order 38 Rules 37B and 37C. Paragraph 13 of the Code of Conduct highlights the importance of an expert witness exercising his independent professional judgment in relation to expert meeting and joint report.”

41.  With the above in mind, I would like to express my general impression on the experts here.

42.  Both experts have given oral evidence at the trial. 

43.  In the course of Ms Lau’s cross-examination in court, I found that, probably because she was too eager to advance the plaintiff’s case, she had on occasions refused to admit to matters suggested to her even though those matters appeared to be obvious.  For example:

(1)  When it was put to her by the defendants’ counsel that there would not be much water spilled on the bathroom floor (other than inside the bathtub) under the normal use of a bathroom, Ms Lau insisted that that would not be the case because toilet is dirty.  In my view, this answer does not make sense, and she had this insistence because she wanted to advance the plaintiff’s case that the water poured onto the floor of the Upper Bathroom had found its way down to the Lower Bathroom;

(2)  Following up on the question above, when the defendants’ counsel asked Ms Lau what would happen if the defendants only used half-wet-half-dry cloth to wipe the floor, Ms Lau said since there would still be water in the cloth, such water would still be able to seep down to the Lower Bathroom.  With greatest respect, this is a clear demonstration that Ms Lau was not an impartial expert.  She was trying to be an advocate of the plaintiff’s case, and would not concede on anything even though what she said in evidence was not sensible;

(3)  While it was Ms Lau’s opinion that the infrared scan, electrical moisture meter test and microwave leakage detection test all showed that there was water leakage problem at the ceiling of the Lower Bathroom, it is undisputed that no fluorescent dye water could be found in the Lower Bathroom after the fluorescent dye test was done. However, when it was put to Ms Lau that the fluorescent dye test had produced an inconsistent result with the other tests, she disagreed.  I have not forgotten her evidence that the dye was absorbed or filtered by the concrete slab.  However, at most this only offered an explanation as to why the result of the fluorescent dye test was inconsistent with other tests.  To deny that there was any inconsistency in the result of this test is, in my view, remarkable, and once again demonstrated her unwillingness to concede even on apparent matters for fear of prejudicing her client’s case;

(4)  In Ms Lau’s expert evidence, she opined that the water which was used to flood the floor of the Upper Bathroom on 20 June 2019 was able to find its way down to the ceiling of the Lower Bathroom after 1 hour. The defendants’ counsel therefore put to her that if water could seep down to the flat below at such a quick speed, then there must exist a crack within the floor slab.  I would have thought this would only be common sense that that was the case.  Yet, Ms Lau refused to admit, but said she did not know.

44.  I regret to say that Ms Lau had given this court a very strong impression that she was an advocate for the plaintiff’s case, rather than assisting the court impartially. This affects the court’s assessment of the reliability of her expert evidence.

45.  On the other hand, compared to Ms Lau, Mr Kan appeared to be much more impartial.  He had no hesitation to agree to Ms Lam (counsel for the plaintiff)’s various suggestions even if the theory or question put to him might seem to be unfavourable to the defendants’ case.  For example:

(1)  He agreed with Ms Lam when she put to him that using his bare hands to touch the ceiling was not reliable because human’s feeling of wetness was subjective;

(2)  When Ms Lam put to him that there was no basis for him to opine that the temperature difference shown by the infrared test was insignificant, he agreed that there was no scientific basis for him to do so.

46.  Furthermore, when he found that he had given an answer in court which he thought was wrong, he would correct himself immediately rather than trying to defend his earlier evidence.

47.  Moreover, when he was asked whether there was waterproofing membrane installed beneath the floor of the Upper Bathroom, he frankly accepted that he did not see that during his inspection.

48.  Before I leave the topic on general reliability of the evidence given by the experts, I should also deal with Ms Lam’s point which stated that:

“Mr. Kan confirmed that he was an architect, and not a chartered engineer, surveyor, and had no qualifications and/or certifications on the methodology of detecting water seepage.”

49.  Ms Lam did not make it clear what she wanted to achieve by drawing the court’s attention that Mr Kan was an architect rather than a chartered engineer or surveyor.  However, I should make it clear that insofar as there is any suggestion that a surveyor is a more qualified person to give expert evidence on water seepage matters over an architect, I would reject that suggestion right away.

D.   SOURCE OF WATER SEEPAGE

D1. The legal principles

50.  It is trite that the plaintiff has to prove where the water came from.  In Leung Yung Chun & Another v Chan Wing Sang & Others [2000] 1 HKLRD 456, it was held by Cheung J (as his Lordship then was) that:

“The burden of proof is clearly on the plaintiffs to show that the source of water came from Mr Chan’s flat. As rightly pointed out by Leong JA in 張秀玲及吳炳漢對鄭禮莊(CACV268/98), there is no presumption that the source of leakage would necessarily come from the flat above…” (at 461 I – J)

51.  Further, it is not for the defendants to find out or identify the real source of the water seepage or to prove that its origin did not come from the Upper Bathroom[2]. Neither is it necessary for the Court to find the real source of the water seepage problem.[3]

D2. Source of the seepage

52.  As confirmed by Ms Lam, the plaintiff’s case is that the source of the water seepage was from the Upper Bathroom, “due to its damaged waterproof membrane and leakage from its drainage pipes system”[4].

53.  She accepted that the absence or damage of the waterproofing membrane beneath the floor of the Upper Bathroom per se would not lead to any water leakage problem, because the problem was caused by water.  Hence, the plaintiff has to prove that there was water coming from the Upper Bathroom.

54.  It was because of this that Ms Lam fairly accepted that, as far as “leakage from its drainage pipes system” is concerned, the plaintiff had the burden to prove that there was leakage from at least one of the following 4 outlets in the Upper Bathroom:

(i)  The water closet;

(ii)  The water basin;

(iii)  The floor;

(iv)  The bathtub.

55.  I will first of all explain briefly about these 4 drainage outlets in the Upper Bathroom.  I will then turn to consider various reports which have been placed before the court and other relevant matters.

D2.1     The drainage outlets

56.  There is no dispute that the drainage pipes of the water closet and the floor of the Upper Bathroom went through the external wall and connected to the communal stack pipe without going through the floor slab between the Upper Bathroom and the Lower Bathroom. 

57.  As far as the wash basin drainage pipe is concerned, Mr Kan opined that its route was similar to those pipes connecting the water closet and floor drainage outlets as described above.  On the other hand, while Ms Lau knew that such a pipe went into the wall, she was not sure whether it went out directly to the outer surface of the external wall or whether it travelled to other places before going out.  As Ms Lau was not sure about it, I would accept Mr Kan’s evidence on this matter, which was also supported by various photographs taken in the Upper Bathroom.

58.  In relation to the route of the bathtub drainage pipe, Ms Lau said she was not sure about it.  On the other hand, Mr Kan told the court, by reference to a photograph taken at the bulkhead of the Upper Bathroom, that the bathtub drainage pipe of the 14^th Floor en-suite bathroom ran vertically downwards, connected to a water-seal bottle trap within the bulkhead of the Upper Bathroom, and then led horizontally to the external wall and connected to the communal stack pipe “Stack 1”.  Mr Kan also stated that even though he had not inspected the bulkhead of the Lower Bathroom, the running of the bathtub drainage pipe of the Upper Bathroom should be the same, namely, going down vertically to the bulkhead of the Lower Bathroom, and then left the Lower Bathroom horizontally to the external wall and connected to the communal stack pipe “Stack 1”.  I accept that that was the case, because this is supported by the markings on the typical floor plan: there is nothing therein which shows that the running of the bathtub drainage pipe of any individual floor was different from other floors of the Building.

D2.2     Experts’ evidence

59.  As aforesaid, both experts had inspected the Upper Bathroom and the Lower Bathroom on 20 June 2019 and 12 August 2019. Various tests had been conducted by Ms Lau and her colleagues.  Mr Kan accepted that the data obtained by Ms Lau’s team was correct.  What he disagreed on was only the interpretation of such data.

D2.2.1    Visual inspection

60.  Ms Lau accepted in court that the visual inspection conducted in the Lower Bathroom cannot shed light on the source of the water. 

61.  However, she also observed that the ceiling and beam of the Lower Bathroom were peeling, cracked, darkening, rusty, with concrete spalling and exposed metal bars. The wall tiles of the Lower Bathroom were cracked and damaged.  She therefore opined that the Lower Bathroom was suffering from persisting water seepage problem.

62.  With respect, I do not agree with Ms Lau that one can arrive at the conclusion of “persistent water seepage” by merely finding the condition of the Lower Bathroom to be bad on the day of inspection in 2019, particularly in the present case, in which there is no dispute that the Lower Bathroom had suffered from water seepage problem from 2010 onwards, and that there were photographs showing that the condition of the Lower Bathroom was not good since 2010.

63.  Indeed, it was Mr Kan’s opinion that there was no doubt that the Lower Bathroom had been subjected to water seepage in the past, and that it could be seen from various photographs that the exposed steel bars had become rusty for some years.  He stated that once the steel bars had become rusty, the affected area could gradually expand, and the concrete would spall through the years, even if there was no persistent water seepage problem. I accept Mr Kan’s evidence.

64.  I have mentioned above my acceptance of Mr Kan’s evidence that the drainage pipes of the water closet, the floor and the wash basin of the Upper Bathroom went through the external wall and connected to the communal stack pipe on the outside of the external wall of the Building.

65.  As pointed out by Mr Lee for the defendants, in relation to those parts of the drainage pipes which were exposed, any seepage could have been noticed by visual inspection.  However, no evidence had been presented to the court that any problem with those parts of the pipes had ever been found under visual inspection.

66.  In respect of the parts of the drainage pipes which were embedded within the external wall, of course no visual inspection could be done thereof unless they were removed from the external wall.  However, it was Mr Kan’s uncontradicted expert evidence that:

(1)  It is unlikely that there would be seepage at those parts of the drainage pipe which came in one piece without connection point (“駁口位”);

(2)  In the event that water did seep out from that embedded sections of the drainage pipe, water would find its way through the weakest point and escape through the cement sealing around the drainage pipes through the external wall. The chemical reaction between such water and cement would create stains on both the interior face and the exterior face of the external wall.  However, no such stain mark was reported to be found at all material times.

D2.2.2      Infrared scan

67.  At the outset, it should be pointed out that there is no dispute that infrared scan at the Lower Bathroom per se cannot tell the source of the water (if any).

68.  However, this method may indicate whether the Lower Bathroom was still subjected to ongoing water seepage problem at the time of the test.

69.  In this regard, having referred to the “exceptionally low temperature” which was detected at a number of spots in the ceiling and the beam in the Lower Bathroom, Ms Lau held the view that the water seepage problem was persistent. 

70.  On the other hand, while Mr Kan accepted that there was thermal variance in the concrete of the ceiling of the Lower Bathroom, he did not consider the difference to be significant, and it should not be described as “exceptional”. 

71.  He also opined that:

“It should also be noted that on date of the First Joint Inspections, the relative humidity was 67% - 88% as recorded in item 4.2 of the Data Report. One should expect that, inevitably, there would be water molecules present within the concrete slab, as concrete is not an impervious material, and, therefore, could have slight variations in temperature, depending on the density of the concrete and concentration of atmospheric moisture there within. Furthermore, the dilapidated condition of the concrete, with varying thicknesses at different parts of the ceiling slab, the scrapping away of some of the surface layer due to aging of the building elements, and the presence of steel reinforcements inside the concrete should also affect the scanned images.”[5]

72.  With respect, I do not accept Mr Kan’s explanation given on the basis of high humidity on the day of inspection, because if the general humidity level would have any impact on the temperature of the ceiling, such an impact should affect the entire ceiling.  It should be borne in mind that the infrared scan test was to detect the differences in temperature between different areas at the ceiling.   The factor of high humidity should only affect the temperature at the surface of the ceiling in absolute sense, but not relative sense.

73.  As to Mr Kan’s view that the results of the infrared scan would be affected by the varying thicknesses at different parts of the ceiling slab, the scrapping away of some of the surface layer due to aging of the building elements, and the presence of steel reinforcements inside the concrete, I also find it difficult to accept.  If Mr Kan was right, then I would have thought the images shown by the scan would be more or less consistent with the pattern of “scrapping away of some of the surface layer” and/or the pattern of reinforcement bars.  However, I do not find that was the case upon comparison of the scan images and the photographs taken of the actual scanned locations. 

74.  As to whether the differences in temperature at different scanned locations were significant or not, this court had not been told about any objective standard which may be made use of to come to any conclusion.   However, as I have found that Mr Kan is a more reliable expert witness than Ms Lau, I would prefer his view in this regard.

75.  On 20 June 2019, a fluorescent dye test had been done at the Upper Bathroom for 1 hour.  Infrared scan tests, electrical conductivity sensory tests and microwave detection tests had been done at the Lower Bathroom both before and after the said fluorescent dye test.  It was Ms Lau’s opinion that the source of the water seepage was the Upper Bathroom because (i) the electrical conductivity sensory tests show that after the fluorescent dye test, the ceiling had become wetter than before; and (ii) there were locations with exceptionally low temperature both before and after the fluorescent dye test.

76.  In this regard, Mr Lee for the defendants had made the following argument:

“The Infrared Scan Test is also inconsistent with the Electrical Conductivity Sensory Test:

(a) The second image in [B/162] shows that the part of the ceiling near the ceiling lamp was cooler before the Fluorescent Dye Test. Ms Lau said these were indications of water seepage. However, the moisture contents of check points 10 and 11 were respectively 27.3 and 25.6 (i.e. all below 35) [B/165]. The two test results were inconsistent with each other.

(b) After the Fluorescent Dye Test, it did not indicate that the area near the ceiling lamp had cooler temperature [B/163]. However, the moisture contents of check points 10 and 11 both increased respectively to 27.9 and 32.4 [B/165]. Again, the two test results were inconsistent with each other.

(c) Also, the third image in [B/163] depicted the corner between the two external walls (i.e. check point 17 in [B/164]). As revealed in [B/163], that part of the ceiling became cooler after the Fluorescent Dye Test. However, this is inconsistent with the Electrical Conductivity Sensory Test. In [B/165], the moisture content near check point 17 actually dropped from 22.5 to 22.3 after the Fluorescent Dye Test.”

77.  Ms Lam could not give any answer to these observations made by Mr Lee.

78.  On the basis of the above arguments, I accept that even if a particular area at the ceiling of the Lower Bathroom was shown to be blue in colour in the infrared scan images (i.e. the area with the alleged exceptionally low temperature), that does not necessarily mean that that area was subjected to ongoing water seepage problem.

D2.2.3   Fluorescent dye test

79.  Fluorescent dye test was conducted by Ms Lau on 20 June 2019 at all the drainage outlets, on the floor and at the wall next to the bathtub of the Upper Bathroom.  No colour water could be found anywhere in the Lower Bathroom on 20 June 2019 or 12 August 2019.

80.  It should be noted that, according to the Professional Guide to Water Seepage (“the Guide”) prepared by the Building Surveying Division of the Hong Kong Institute of Surveyors:

“If colour dye is not observed anywhere in or around the seepage area within three weeks of the flood test, the test should be negative.”[6]

81.  I agree with Mr Lee’s argument that the above shows that in normal cases, 3 weeks should be allowed for the colour water to reach the seepage area before negative results are declared.   However, in the present case, the experts had waited for nearly 8 weeks before they did the 2^nd inspection.  Yet, no colour water could be found in the Lower Bathroom.  There is therefore no doubt that a negative result had been returned in this test.

82.  The above supported the defendants’ case that the water seepage problem in the Lower Bathroom was not caused by any leakage in the drainage system of the Upper Bathroom.

83.  However, Ms Lau opined that such a negative result was neither here nor there because there was a possibility that the colour content of the dye might be absorbed or filtered by the concrete slabs, while the moisture could still reach the ceiling of the Lower Bathroom.  She made reference to section 4.2.1 of the Guide, in which the following was described as one of the pitfalls of the fluorescent dye test:

“Absorption or filtration of dye solutions along the cracks can result in the dye being unable to reach the damp zone.”[7]

84.  It should be noted that, according to Ms Lam, the results of the other tests conducted proved that the colour water had found its way from the Upper Bathroom to the Lower Bathroom within 1 hour.  Mr Kan opined that, if that was so, the chance of the dye solution being adsorbed while it was on its way was low.  I accept Mr Kan’s evidence, because this makes more sense to me than Ms Lau’s theory.

85.  Furthermore, I accept Mr Kan’s opinion that if water had penetrated down so readily to the bottom of the slab within 60 minutes in the manner as suggested, there should have been an obvious loss of the 20-25 mm deep puddle of water on the floor of the Upper Bathroom.  However, there was no sign of such happening.

86.  Another theory relied on by Ms Lau in supporting her conclusion that the fluorescent dye test did show that water had seeped from the Upper Bathroom to the Lower Bathroom was that since the colour water flooded the floor of the Upper Bathroom was seen to be able to seep underneath the door kerb and overflow to the Master Bedroom at which normally there was no waterproofing membrane, this demonstrated that water could be able to flow down to the Lower Bathroom through areas at the Upper Flat at which no waterproofing membrane was installed.

87.  The short answer to this theory is that after all, no colour water could be found in the Lower Bathroom, no matter whether it was after 1 hour or 7.5 weeks of the flooding test. 

88.  Furthermore, I find that it was more likely than not that there was no waterproofing membrane installed beneath the floor of the Upper Bathroom.  According to Mr Kan’s evidence, for those buildings which were constructed in the 1980s and early 1990s, waterproofing membrane would normally not be installed to cover the whole floor slab beneath the bathroom floor.  The Occupation Permit of the Building was issued in 1987, so I would infer that the Building was built in the 1980s. 

89.  That means the condition of the floor slab beneath the floor of the Upper Bathroom on one hand and that beneath the floor of the Master Bedroom on the other hand should be the same – neither was protected by any waterproofing membrane.  That being the case, whether the colour water could seep into the area of the Master Bedroom is neither here nor there.

90.  Moreover, I accept the defendants’ evidence that they would not flood the Upper Bathroom with water, but would only cause the Upper Bathroom to be cleaned by wiping it with half-dry-half wet cloth.  In such a case, I find that there would not be sufficient water to flow down through the crack of the floor tiles (even if there was any) and the floor slab.

91.  Before I leave this topic, I should also deal with two other arguments made by Ms Lam. 

92.  Firstly, she has drawn this court’s attention to a number of case authorities in which it had been held that dye tests are not always successful and negative results alone are not definite evidence against the suspected source.  That is of course correct.  However, the application of this proposition depends on the circumstances of the case.  In the present case, the fluorescent dye test was not conducted only once but many times by the Joint Office or its contractors.  I will come back to this point later in the subsequent part of this Judgment.

93.  Secondly, she submitted that, as far as the bathtub was concerned, it was possible for water seepage to occur at the connecting point of the bathtub drain and the bathtub pipe located in the wall of the Upper Bathroom due to blockage, and overflowing water would seep through the wall and flooring of the Upper Flat and run into the concrete slab between the 2 subject flats, causing leakage on the ceiling of the Lower Flat.

94.  With respect, as the plaintiff’s counsel, it is not sufficient for Ms Lam to put forward possibilities.  The plaintiff has to prove its case.

95.  Moreover, as fairly accepted by Ms Lam, if there was indeed any leakage as described by her, the water which leaked out would flow downwards to the false beam bulkhead (木廊) in the Lower Bathroom.  However, it is evident that there was no trace of water found at that location.

96.  This argument therefore cannot assist the plaintiff.

D2.2.4    Electrical conductivity sensory method

97.  Ms Lau opined that as the moisture content recorded by this method in relation to some of the locations at the ceiling of the Lower Bathroom had increased to higher than 35% after the fluorescent dye test was done, this would support her view that the ceiling and the beam of the Lower Bathroom was still persistently affected by water seepage at the time of the test.  In her own words:

“原告人物業單位主浴室天花及橫樑部份測試點的濕度讀數均於螢光色水測試後出現輕微上升情況並超過35度，表示原告人物業單位（即12樓1室）主浴室天花及橫樑仍正受滲水影響，並出現明顯滲水情況”

98.  Mr Lee for the defendants had made, among others, the following observations on the readings obtained by the Electrical Conductivity Sensory Method before and after the fluorescent dye test:

(1)  Before the fluorescent dye test, 3 out of 20 check points at the ceiling of the Lower Bathroom were found to have readings of over 35 (i.e. check points 3, 5 and 9). After the fluorescent dye test, the number of check points with readings of over 35 increased only to 5 (i.e. check points 1, 2, 3, 5 and 14);

(2)  On the other hand, 10 out of those 20 check points were found to have lower moisture content levels (i.e. check points 3, 4, 6, 8, 9, 12, 15, 17, 18 and 19);

(3)  More particularly, check point 9 had a moisture content level of 40.4 before the fluorescent dye test, but the moisture content level decreased to 33.8 (i.e. below 35) after the fluorescent dye test. If the decrease of the moisture level at check point 9 was due to external factors (e.g. different hand pressure or different contact areas), then external factors could also play a role at the check points where moisture content had increased.

99.  If the colour water could flow down within 1 hour as alleged, how come the experts could not see any such colour water at the Lower Bathroom? 

100.  Furthermore, if Ms Lau was right that the ceiling of the Lower Bathroom had been extensively affected by water seepage coming from the Upper Bathroom, how come there were only 2 out of 20 check points at which the readings were increased from less than 35 to more than 35 after the fluorescent dye test?  I should perhaps also add that out of those 2 check points, one of which had a reading of 33.5 already even before the fluorescent dye test was done.

101.  Mr Kan suggested that there were other factors which might affect the readings.  Indeed, the Guide also mentioned about this pitfall.  On my part, I am unable to say which of those factors had affected the readings obtained by Ms Lau.  What I am able to say though is that I have great reservation on the conclusion reached by Ms Lau in the way she did in relation to this test by reason of all the observations and questions mentioned above.

D2.2.5   Microwave detection

102.  Two microwave detection tests were done on 20 June 2019, before and after the fluorescent dye test.

103.  Ms Lau opined that the microwave detection tests had revealed the source of water seepage in the Lower Bathroom to be from the flooring of the Upper Bathroom as the water patterns showed that the water did flow from top to bottom, and ultimately spreading out at the Lower Bathroom’s ceiling.

104.  I do not accept Ms Lau’s conclusion.

105.  Firstly, while the images captured at 30mm, 70mm and 110mm from the ceiling of the Lower Bathroom showed different moisture content at various strata of the concrete, they did not show the movement of the water at all, particularly when the patterns of the “damp areas” at the planes of 30mm, 70mm and 110mm into the slab did not correlate with one another.

106.  Secondly, if we compare the images taken before and after the fluorescent dye test, it can be seen that the alleged water paths were quite different.  I accept Mr Lee’s argument that this is inconsistent with there being an established through crack(s) which rendered it possible for the water to travel from the Upper Bathroom to the Lower Bathroom within 1 hour.

107.  Thirdly, as Mr Kan observed, in both sets of images captured before and after the fluorescent dye test, the so-called “damp areas” mainly concentrated at the plane of 30mm from the ceiling of the Lower Bathroom. The water/moisture found at the planes of 70mm and 110mm respectively (in other words, closer to the floor of the Upper Bathroom) was less.  He opined that this is illogical, given that the Upper Bathroom was flooded with colour dye water for 60 minutes. He held the view that if the floor finish of the Upper Bathroom could allow water to seep through, water or moisture should have concentrated much nearer to the floor level of the Upper Bathroom, but not further away from it. Hence, he took the view that there is no reason to conclude that there was water seepage from the Upper Bathroom.

108.  Ms Lau explained that since the water had flowed from the top to the bottom of the slab due to gravity, it would be easier for water to gather at the 30mm plane than at the 110mm plane.

109.  I do not accept Ms Lau’s evidence in this regard, for her theory was made on the assumption that by the time the second microwave detector test was done on 20 June 2019, the seeping process of the colour water had completed.  However, if there was really water from the Upper Bathroom floor seeping through the floor slab, I would have thought the seeping process was a continuous one.  In other words, water should be found not only at the location near the Lower Bathroom but also near the Upper Bathroom.

110.  Furthermore, if Ms Lau’s theory was a valid one to explain why there was less water at the 110mm plane than the 30mm plane, then I do not understand why she would assume that the water would somehow gather at the 30mm plane but not flowed further downwards.  She did not explain further on this.

111.  Fourthly, Ms Lau’s theory is also inconsistent with the result of the test in that it was shown that the 70mm plane had consistently less water/moisture than the 110mm plane and the 30mm plane. 

112.  Fifthly, if Ms Lau was right, then the concentration of water/moisture at the 30mm plane after the fluorescent dye test should be higher than that before the fluorescent dye test was done.  However, it was shown not to be the case.

113.  Sixthly, I agree with Mr Kan that the test only showed that there was water/moisture at the planes of 30 mm, 70 mm and 110 mm from the ceiling of the Lower Bathroom, but not where the water/moisture came from.    Given Ms Lau’s admission in court that she did not know the thickness of the floor slab, she could not comment on whether the 110 mm plane was close to the floor of the Upper Bathroom enough that it could be inferred that the water/moisture was more likely than not to be coming from the Upper Bathroom. In other words, the test could at most show that water had flowed from the 110mm to the 30mm plane.  However, as explained above, I do not think the result herein could even support this.

D2.2.6   Flow meter test

114.  The flow meter test was done to check whether there was any leakage to the water supply pipe.  Since the plaintiff’s case, as confirmed by Ms Lam in her final submissions, was that the water seepage problem of the Lower Bathroom was only caused by the drainage pipes but not fresh water pipe of the Upper Bathroom, the result of the flow meter test is irrelevant for our purpose herein.

D2.2.7   The external wall

115.  In the joint expert report, Ms Lau opined that the external wall was not the source of the water seepage problem of the Lower Bathroom because, according to the infrared scan conducted on 12 August 2019 (the date when the experts conducted their second joint inspection), there was no thermal difference detected at the external wall. 

116.  No infrared scan was conducted at the external wall when the experts carried out their first inspection on 20 June 2019.

117.  However, it is noted that:

(1)     There had been a total of 102.1mm rainfall within the 7-day period before the day when the experts conducted their first joint inspection at the premises on 20 June 2019 (i.e. from 13 June 2019 to 19 June 2019);

(2)     There was only a total of 1.1mm rainfall within the 7-day period before the second joint inspection carried out on 12 August 2019 (i.e. from 5 August 2019 to 11 August 2019).

118.  Given that there was very little rainfall within the 7-day period before the infrared scan was done on 12 August 2019, I seriously doubt the probative value of such a test. 

119.  In any event, it is trite that the court does not have to find the real source of the water seepage. 

120.  As I pointed out to Ms Lam at the trial, for the sake of argument, the position may be different if it is evident that there were only two possible sources of water, and hence the exclusion of one may entitle the court to infer that the remaining one was the source of the problem. However, there is no expert evidence in this regard.

121.  What we have in Mr Chow’s evidence in fact indicated that there might well be another source of water.  In paragraph 45 of Mr Chow’s witness statement, he stated that:

“On 16^th October 2017, the Second Surveyor also noticed a large hole on the internal wall between the Upper Bathroom and the master bedroom which was fully covered up by wallpaper/plastic tapes which the 1^st Defendant did not remove for our inspection. The 1^st Defendant said water was seeping out of the internal wall some years ago. He said he did not do anything but the seepage somehow just stopped. On 29^th November 2017, high moisture content levels of about 50% were detected by me along the internal wall close to the aforesaid large hole. The location of the hole was in line with the most affected spots on the ceiling of the Damaged Bathroom. Rust/water stains were also found on the Upper Bathroom’s exposed concrete slab and nearby areas. These indicated that the Upper Bathroom and/or the Defendants’ Premises were, and still are being affected by water seepage, and were possibly the source of the water seepage affecting the Damaged Bathroom below.”

122.  I do not think there can be any dispute that any water within the internal wall referred to by Mr Chow could not come from the drainage system of the Upper Bathroom. 

123.  Ms Lam submitted that the plaintiff’s case was that such water came from the external wall.  We have no expert evidence in this regard.

D2.3    The Joint Office’s fluorescent dye tests

124.  On 25 October 2010, 3 February 2012, 31 May 2013, 10 July 2015 and 20 November 2016, the Joint Office had caused fluorescent dye tests to be conducted at the drainage system (i.e. water closet, water basin, floor and bathtub) of the Upper Bathroom.  All test results were negative.

125.  Samples of tissue and plaster obtained from the ceiling of the Lower Bathroom on different occasions in 2012, 2016 and 2018 respectively had been sent to the Government Laboratory for analysis.  It was confirmed that no colour dye could be found.

126.  Moreover, pond tests to the floor and spray tests to the wall next to the bathtub had also been conducted on 17 April 2012, 30 July 2013 and 4 March 2017 by contractors engaged by the Joint Office with negative results.

127.  I have dealt with Ms Lau’s view that the dye solution might well have been absorbed by the floor slab in the previous part of this Judgment, and I will not repeat that here. 

128.  What I should supplement here is that fluorescent dye tests had been conducted not only once, but many times in all these years.  In my view, it cannot be a coincidence that fluorescent dye was nowhere to be found in the Lower Bathroom on all those occasions.  The consistent test results show that the water at the ceiling of the Lower Bathroom did not come from the Upper Bathroom.  It is because of this unique feature in the present case that I hold the view that the case authorities referred to by Ms Lam (such as Lam Ting Kwan & Another v Teamwell Corporation Limited [2019] HKDC 1593) to the effect that “negative dye test results are not definite evidence against the suspected source” should be distinguished.

D2.4    The HKSL 2016 Report

129.  The HKSL 2016 Report was issued on 8 October 2016.  It was concluded therein that the water seepage problem at the Lower Bathroom was caused by:

(1)  a crack at the external wall surrounding a pipe outside the Upper Bathroom;

(2)  the damaged waterproofing membrane underneath the floor, the damaged walls and the damaged drainage pipes of the Upper Bathroom.

130.  What should be particularly noted here is that water droplet(s) was/were found at the ceiling of the Lower Bathroom at a location which was near the external wall.  Coupled with the crack found referred to above, there was prima facie evidence that the source of the water seepage problem was the external wall.

131.  At this point, we should be reminded of Mr Kan’s evidence (which has been accepted by this court) that it could be seen that the exposed steel bars at the ceiling of the Upper Bathroom had become rusty for some years, and that once that was the case, the affected area could gradually expand, and the concrete would spall through the years. 

132.  This, in my view, had provided a possible reason why the condition of the Lower Bathroom had become worse despite the fact that the source of the water seepage was not found to be the Upper Bathroom or the external wall in 2019. 

133.  In Ms Lam’s reply submissions, she argued that:

“Even if any External Wall defects was indeed one of the causes of water seepage into the Upper Flat and/or Upper Bathroom at some unknown point in time as alleged (of which is not admitted), the fact that the Upper Bathroom had lacked a waterproof membrane (or that it was damaged or defective) would still have been the reason for the seepage in the Damaged Bathroom. If that is the case, Ds clearly knew about the leakage in the Upper Flat as well as the fact that they lacked waterproof membrane (or that it was damaged or defective) but having failed to take any action to remedy or stop the water seepage would still render the Ds’ negligent.”

134.  I have made a finding that there was no waterproofing membrane installed beneath the floor of the Upper Bathroom when the Building was constructed in the 1980s.  That being the case, I do not think the defendants can be blamed as suggested by Ms Lam.  If it was the external wall which was the source of the problem, then I do not think the defendants should be required to install a waterproofing membrane beneath of the floor of the Upper Bathroom for the purpose of protecting the occupiers below.

135.  I should also point out that the above conclusion in the HKSL 2016 Report against the Upper Bathroom was reached without any inspection/test done at the Upper Bathroom, and it was arrived at by relying primarily on the test result of microwave detection.  However, from the images captured, it could be seen that the 30mm plane was much “wetter” than the planes at the depth of 70mm and 110mm, and the 110mm plane was also drier than the 70mm plane.  These, in my view, do not support the conclusion that water was flowing down from the Upper Bathroom to the Lower Bathroom. 

136.  It should also be added that the result of this test is consistent with that done in 2019, in that the 30mm plane was much “wetter” than the 70mm plane.  Ms Lau’s theory that water was flowing from the top to the bottom is simply not supported.

D2.5     Silver Consultants 2017 Report

137.  The Silver Consultants 2017 Report was prepared by a Mr Leung Ka Chun.  No leave had been granted by the court to admit this report as an expert report as such.  I will therefore not give any weight to the opinion expressed therein.

138.  What I would deal with here is the allegation in the Silver Consultants 2017 Report that certain pink stains were found at the ceiling of the Lower Bathroom on 16 October 2017, and it was said that those were colour dye which was used in fluorescent dye test(s) conducted previously. 

139.  I do not accept this allegation because no laboratory test had been done to prove the allegation. 

140.  In her reply submissions, Ms Lam argued that:

“33(3) During cross examination, Mr. Chow explained the mechanism of the laboratory tests that are run by the Joint Office in regards to the nature of the color dye based on information he obtained from his telephone call to the Joint Office. He submitted that the Joint Office explained, the FEDH and the Buildings Department, although are both under the Joint Office, would appoint different contractors who will use different types of color dye to conduct the relevant test. The Joint Office however, would only be able to conduct laboratory tests on color dyes that are used by their own office, and not that of their contractors (in this case for instance, Prudential or Geotechnics). Therefore, the aforementioned laboratory tests are at most inconclusive as to whether the pink stains are from color dye used by the contractors of the Joint Office; and

33(4)    P submits that it is more likely than not that color dye from the color dye tests explain the cause for the appearance of pink stains on the ceiling of the Damaged Bathroom.”

141.  With respect, taking the plaintiff’s case to the highest by reference to what Mr Chow’s said that he was told, the laboratory tests are at most inconclusive.  It would be a quantum leap to say it is more likely than not that the “color dye from the color dye tests explain the cause for the appearance of pink stains on the ceiling of the Damaged Bathroom”.

D2.6    The HKSL 2018 Report

142.  Relying on the result of the microwave detection test, the HKSL 2018 Report concluded that the source of the water seepage problem was the Upper Bathroom. 

143.  Again, no test or inspection had been done at the Upper Bathroom for the purpose of this report. 

144.  Similar to the result obtained for the purpose of the HKSL 2016 Report, it could be seen from the images that the 30mm plane was much “wetter” than the planes at the depth of 70mm and 110mm.  As I explained above, these do not support the conclusion that water was flowing down from the Upper Bathroom to the Lower Bathroom.

D2.7    Use of the Upper Bathroom between 31 July 2017 and late January 2018

145.  It is the evidence of the 1^st defendant that he had caused the 2017 Work to be done at the Upper Bathroom on 31 July 2017.  To recap, such work included the removal of the floor tiles, the water closet, the wash basin and the tiles covering one side of the bathtub.  The extent of such work was supported by photographs taken at the material time.  The 1^st defendant had also invited the plaintiff and the management office of the Building to do an inspection at the Upper Bathroom, which the management office (but not Ms Kam) did so on 2 August 2017.

146.  It was also the evidence of the defendants that they did not use the Upper Bathroom for half a year (i.e. up to late January 2018).  Although the bathtub had not been removed and theoretically the defendants could still use it during the said 6 months’ period, there is no reason why this court should doubt the defendants’ evidence in this regard. Indeed, it had never been put to either of the defendants that they were lying about their usage of the Upper Bathroom during the said period.

147.  However, despite the fact that the Upper Bathroom was not in use from 31 July 2017 to late January 2018, the plaintiff still complained about water seepage at that time.  On 27 January 2018, Mr Chow sent the following WhatsApp message to the 1^st defendant, in reply to the latter’s enquiry as to whether water seepage was still continuing:

“[…] 如果你冇做過維修，滲水又點會停呢?事實亦冇停止[…]”

148.  Mr Chow also stated the followings in his witness statement:

“The Defendants alleged that they had stopped using the Upper Bathroom for the period from 31^st July 2017 to the end of January 2018. Even if the Defendants stopped using the Upper Bathroom during the said period, which is uncertain and denied, water seepage to the [Lower] Bathroom continued even with the prolonged fine weather conditions during the said period.”

149.  I should perhaps add here that according to the WhatsApp messages placed before the court, Mr Chow had sent a message to the 1^st defendant on 1 February 2018 and put on record thereby that he (Mr Chow) heard that there was noise coming from ongoing work (工程) at the Upper Flat at 11:50am.  Similar messages had been sent on 2 February 2018 and 5 – 8 February 2018.  These, in my view, support the defendants’ evidence that they did not use the Upper Bathroom up to late January 2018 because it seems that the reinstatement work of the Upper Bathroom was only started in early February 2018.

150.  If the water seepage problem continued even though the Upper Bathroom was not in use at all, that would be an indication that the source of the problem was not the drainage pipe of the Upper Bathroom as alleged. 

151.  When Ms Lau was asked to explain why the Lower Bathroom would still suffer from water seepage problem despite the defendants’ said suspension of use of the Upper Bathroom, she initially answered that she did her test in November 2018.  In my view, she was avoiding the question, because it is naturally a point which is unfavourable to her client.  When it was further put to her by Mr Lee that the continuation of the water seepage problem showed that the water was coming from a source other than the Upper Bathroom, she stated that the water which found its way down to the Lower Bathroom might probably be the water previously drained away from the Upper Bathroom.  In her own words:

“我都唔知道當其時係咪真係無人用過水，所以我都好懷疑係咪水尾呀其實，無論你點講都好啦”

152.  I was most surprised that such an answer would come from the mouth of an expert.  Again, this has demonstrated that Ms Lau was not impartial at all:

(1)  She had assumed the role as an advocate and challenged a factual matter which was put forward by the defendants (which, as aforesaid, even the plaintiff’s counsel did not challenge);

(2)  In fact, such an answer was self-contradictory. If the defendants were really still using the Upper Bathroom during the said 6-month period, then if Ms Lau was right that the source of water was the Upper Bathroom, such water would not be “水尾” at all;

(3)  On the other hand, if the defendants had suspended their use of the Upper Bathroom during the said 6-month period, a question would arise as to why the alleged “水尾” could go on to affect the Lower Bathroom even by the end of those 6 months.  This is in fact also contrary to Ms Lau’s own evidence that the water could seep from the Upper Bathroom to the Lower Bathroom within 1 hour;

(4)  She basically was saying that she would not change her opinion “no matter what the defendants’ counsel said”. 

153.  Ms Lam argued that there was no data put forward by either party as to the extent of the water seepage during the said 6-month period. She suggested that it could have been possible that water seepage had lessened during this period, and increased after normal usage was resumed.  With greatest respect, this is pure speculation without the backing of any evidential basis, which must be rejected.

D2.8    Conclusion

154.  Having taken all the above matters into account, it is my finding that the plaintiff has failed to prove, on the balance of opportunities, that the water seepage problem which affected the Lower Bathroom was caused by the defective drainage system of the Upper Bathroom as alleged. Neither am I satisfied that the Lower Bathroom is still suffering from persistent water seepage problem.

155.  Even though the plaintiff could prove that the Lower Bathroom had suffered from water seepage problem in the past, as I pointed out at the earlier part of this Judgment, this per se is not enough for the purpose of establishing liability herein, for it is trite that the plaintiff is also obliged to prove the source of the water.  The plaintiff cannot simply assume that the water must come from the flat above.  However, unfortunately, the plaintiff (and its expert) had, in a way, made such an assumption all along without concrete proof.

156.  The plaintiff’s action herein should therefore be dismissed.

157.  For the sake of completeness, in case I am wrong, I would proceed to consider whether the defendants have taken reasonable actions in response to the plaintiff’s complaint of the water seepage problem and also on the relief claimed below.

E.    REASONABLENESS OF THE DEFENDANTS’ ACTION

E1.   The legal principles

158.  Ms Lam has referred this court to the case of Loke Yuen Jean Take Alice v Wong Kit Ying and others [2019] HKCFI 1895, in which M Ng J, having considered a number of authorities, had the following to say on the duty to abate nuisance:

“Thus, the defendant’s duty is a ‘measured’ duty, which is determined by what is fair, just and reasonable as between two neighbours, having regard to all the circumstances, including the extent of the foreseeable risk, the available preventive measures, the cost of such measures and the resources of both parties. In my view, the above observations in Goldman and Leakey & ors are directed to what a reasonable person in the shoes of the defendant would have done, so the label of nuisance or negligence has no real significance. The common law is concerned in working out the fair and just content/incidence of a neighbour’s duty rather than affixing a label and inferring the extent of the duty from it.” (at paragraph 59)

159.  I will therefore consider the question of “reasonableness” in respect of the defendants’ action below.

E2.   2010 – 2014

160.  The first complaint about water seepage problem at the Lower Bathroom was made on behalf of the plaintiff to the Joint Office on 15 September 2010.

161.  As a result, the Joint Office had caused colour water test to be done at the Upper Bathroom.  However, the source of water seepage could not be ascertained.

162.  Repeated complaints had been made to the Joint Office subsequently. Upon the receipt of each complaint, the Joint Office had arranged inspections and tests to be done at the Upper Bathroom.  When the Joint Office was unable to find out the source of the water seepage itself, it would engage a contractor to do more investigation work.  It is undisputed that whenever there was any request made by the Joint Office or its contractor to enter the Upper Bathroom to do investigation, the defendants had been cooperative.

163.  The defendants stated that they did not know who had actually made the complaint until 2014.  They said they were not curious about it and they never asked.  On my part, I find this difficult to believe. It is inherently improbable that a flat owner, who had been repeatedly asked to allow the Joint Office to do tests and inspection in his premises, would not feel the need to ask who actually was complaining about water seepage.

164.  Be that as it may, the fact remains that the defendants had been cooperative and did allow the Joint Office and its contractors to enter their flat as and when it was considered necessary by the Joint Office. 

165.  Even if the defendants knew in the period between 2010 and 2014 that it was the occupants of the Lower Flat who were complaining about water seepage, I do not think the law would impose a more stringent requirement on them in terms of taking reasonable actions.  The defendants had allowed the Joint Office to do tests, and in my view, they could reasonably expect that if it was found by the Joint Office that it was the Upper Bathroom which was causing water seepage problem downstairs, they would be informed accordingly.  On the other hand, if it could not be shown by those tests caused to be done by the Joint Office that the Upper Bathroom was the source of the problem, I do not think the defendants should be expected to do further investigation themselves.  Hence, I do not think it matters as to:

(1)  whether the defendants had asked the Joint Office for the identity of the complainant; nor

(2)  whether the defendants had taken the initiative to find out the results of the tests undertaken.

166.  The situation in the present case must be distinguished from other cases in which the first complaint of water seepage was made directly by the complainant to the owner of the suspected flat (whether through the management office or not).  In such a case, the owner of the suspected flat would be under a duty to find out whether his flat is the source of the problem.

E3.   The 2014 Work

167.  It is undisputed that the 1^st defendant only inspected the Lower Bathroom for the first time on 6 May 2014.  According to his evidence, as he found that the condition of the Lower Bathroom was quite bad, he started to worry and wonder whether there was really any seepage of water from the Upper Bathroom.  He therefore instructed his contractor to carry out the 2014 Work.

168.  In relation to the 2014 Work, Ms Lam had made the following arguments.

169.  First of all, she alleged that the defendants had caused the 2014 Work to be done secretly.  I do not accept this allegation.  I accept the 1^st defendant’s evidence that he had informed the management office about such work beforehand because permission had to be sought from the management office for any such work to be done.

170.  Ms Lam then drew the court’s attention to a photograph taken during the 2014 Work which showed that the concrete flooring of the Upper Bathroom was wet.  The 1^st defendant explained that that was the “leftover” water (水尾) spilled onto the ground upon the removal of the water basin and the water closet.  I accept his explanation. 

171.  Ms Lam submitted that the concrete flooring was wet because of the defective (or lack of) waterproofing membrane in the Upper Bathroom.  As I have mentioned above, I take the view that there was no waterproofing membrane installed on the floor of the Lower Bathroom because the Building was constructed in 1980s.  However, I cannot see the relationship between the waterproofing membrane and the wetness of the concrete floor.  If the tiles on the floor had been removed, the concrete floor would be unavoidably wet if water was spilled thereon. 

172.  Ms Lam also argued in her written closing submissions that the defendants had replaced the fresh water pipes in the Upper Bathroom.  Given the plaintiff’s case that the seepage was not caused by any leakage of the fresh water pipe in the Upper Bathroom, whether there was such replacement is totally irrelevant for our purpose.

173.  Ms Lam criticised that the 2014 Work was “unreasonable, unnecessary and did not serve any remedial purpose”[8] because:

(1)  Despite having removed the entire toilet and concrete surface of the Upper Bathroom’s flooring, the defendants did not invite any expert or third party to inspect or test whether the Upper Bathroom was the source of water seepage or carry out any remedial actions;

(2)  The act of entirely demolishing the tiles of the Upper Bathroom and removing the toilet would inevitably damage the waterproof membrane (if any) on the flooring;

(3)  There is clearly no evidence that the 2014 Works included reinstatement of the waterproof membrane on the floor of the Upper Bathroom.

174.  I accept the 1^st defendant’s evidence that the whole purpose of the 2014 Work was to find out whether the Upper Bathroom was really the source of the water seepage problem of the Lower Bathroom.  That was why he engaged a renovation contractor to remove everything and check thoroughly whether there was any leakage in the drainage pipes.  Although there is no evidence that such a renovation contractor was a professional as such (e.g. a surveyor).  I do not think a professional is needed to check whether there was any problem with the drainage pipes.  I have no hesitation in rejecting Ms Lam’s first criticism referred to above.

175.  As I have found that there was no waterproofing membrane beneath the floor of the Upper Bathroom, the rest of Ms Lam’s criticisms are irrelevant.

176.  I note that Mr Chow had the following to say in his witness statement:

“33. The 2014 Work was a destructive, extensive and costly undertaking. Put simply, it is a ‘break up everything and take a look’ method. They had to engage workmen to smash the bathtub, the floor tiles and wall tiles, remove the water closet, the wash basin, all the pipes, and break up and remove the top layer of the concrete slab (together with the water-proofing membrane underneath) to expose the pipes and joints. They would then try to look for water stains with their naked eyes. As they purportedly did not see any water stains with their naked eyes, they then installed a new bathtub, new floor tiles, new wall tiles, new water closet and new wash basin and reconnected all the pipes and accessories. They also had to stop using the Upper Bathroom for a considerable period of time. Hence, all these elaborate work and considerable expenses just for a visual check with their naked eyes. The 1^st Defendant refused to disclose how much he spent on the 2014 Work. The Defendants also did not offer any evidence to support their claim that no water stains or defects were found. They just reinstated the Upper Bathroom and kept silent until August 2017.

34. In my view, such an extensive, expensive and destructive work was not a sensible or effective way to investigate the cause of the seepage.  There are many tests that can be performed to investigate the cause of water seepage.  Some tests are non-destructive, meaning they will not harm the materials, structure and serviceability of the facility being tested, e.g., pond test, pressure test, electrical resistance (moisture meter) test, infra-red scan, microwave scan, etc.”

177.  It is easy to criticise.  However, with respect, these criticisms are quite unfair.  In my view, when we consider the reasonableness of the defendants’ action, we need to put ourselves in their shoes at the material time, and bear in mind what information they had at that point of time: at that time, on one hand, the 1^st defendant had seen that the Lower Bathroom was affected by water seepage problem, but on the other hand, the defendants also knew that although several tests had been undertaken by the Joint Office, they had never been informed that the Upper Bathroom was the source of the problem.  In my view, the defendants could reasonably assume, at the very least, that even the Joint Office could not confirm that the water came from the Upper Bathroom, because otherwise the defendants would have been informed accordingly.  In this regard, it must be noted that the first test done by the Joint Office was undertaken back on 25 October 2010 (i.e. nearly 4 years before the 2014 Work).

178.  As Mr Chow recognised, the 2014 Work must have brought a lot of inconvenience to the defendants.  It would probably be expensive too.  Yet the defendants decided to cause such work to be carried out.  On my part, I have no doubt that what the defendants had done must have passed the test of reasonableness.

E4.   2015 – 2017

179.  In the course of these 3 years, in the light of the plaintiff’s repeated complaints, the Joint Office had caused further tests to be done in July 2015, November 2016 and March 2017 at the Upper Bathroom. 

180.  On top of that, the plaintiff had also engaged Silver Consultants to look into the problem, and as a result, an inspection was conducted at the Upper Bathroom on 16 October 2017.

181.  There is no evidence that the defendants had been uncooperative, despite the fact that they had basically redone the Upper Bathroom in 2014, and confirmed (at least from their point of view) that there was no leakage from their drainage pipes. 

182.  For the sake of argument, even if the defendants had been told in 2014 by their renovation contractor who was responsible to carry out the 2014 Work that there were leakage problems with the drainage pipes of the Upper Bathroom (it should be reiterated that there was no such evidence), I think it must be more likely than not that the defendants would have asked their contractors to remedy such problems rather than reinstating everything without doing any remedial work to the drainage system, because, even from a selfish point of view, it would not do any good to the defendants if they knew that they would continue to be subjected to a lot of water seepage complaints from their neighbours living in the flat below. 

183.  In other words, no matter whether anything wrong was found upon the opening up of the floor of the Upper Bathroom, when the 2014 Work was completed, the defendants were entitled to be confident that their flat was not causing any (further) seepage problem to the Lower Bathroom.  Yet, they had allowed various inspections and tests to be done at the Upper Bathroom.

184.  I am therefore satisfied that the defendants had taken reasonable steps on their part during this period of time.

E5.   Mr Pun’s Work

185.  Upon receipt of the HKSL 2016 Report, the defendants engaged Mr Pun, a plumber, to do certain work in 2017, in the hope of solving the water seepage problem of the Lower Bathroom.

186.  To recap, the HKSL 2016 Report concluded that the water seepage problem was caused by a crack at the external wall and the damaged waterproofing membrane underneath the floor, the damaged walls and the damaged drainage pipes of the Upper Bathroom.

187.  In this regard, Ms Lam had made the following submissions:

“In 2017, albeit continuous urging of the Ds for remedial action, the Ds only hired Mr Pun to do works which were obviously inadequate, if not irrelevant, to rectifying and eliminating the source of water leakage from the Upper Bathroom. D1 also admitted that Mr Pun was not an expert in the field, and merely a plumber.”[9]

188.  She elaborated further:

“Despite continuous urging of the Ds for remedial action, the Ds only hired a plumber, Mr. Pun (“Mr. Pun”) of whom Ds averred did the following in 2017:

(1)  Replace a water closet outlet pipe (“D’s WC Outlet Pipe”) connecting to the external main sewage pipe, and filled up a gap between the Ds’ WC Outlet Pipe and the external wall of the Upper Flat in May 2017 […]

(2)  Conducted a spray test by spraying water on the external wall of the Upper Bathroom for 1 hour in attempts to allege that the water seepage was caused by the external wall and not by the Damaged Flat. […]

(3)  Opened a hole near the entrance of the Upper Bathroom at a spot corresponding to the Concrete Beam of the Damaged Bathroom below […].”[10]

189.  In relation to the work under items (1) and (2) above, such work (apart from the D’s WC Outlet Pipe which was not found to be leaking) was done at the external wall.  I do not think there can be any dispute that if the external wall was really the source of the problem, it should be the management office (and the Incorporated Owners of the Building) which should have the obligation to cause remedial work to be done.  By engaging their contractors to do work at the external wall, the defendants had done more than what they were obliged to do.

190.  In relation to item (3) of the work, Ms Lam submitted that:

“(a) D1 claimed that he saw with his bare eyes that the inner space of the floor slab had no water marks or signs of water seepage on 15 June 2017 [A/134/§22], but neither Mr. Chow, Ms. Kam nor the Management Office were invited to inspect this hole;

(b) The photograph of this hole revealed it to be shallow and does not correspond with the leakage spot by which the HKSL 2016 Report identified [C3/624-625]; and

(c) It was also admitted by D1 at trial that (i) no professional tools or expert were used to inspect the moisture content of this hole, and that (ii) Mr. Pun had no expertise to find out any cause of water seepage.”

191.  My views are as follows:

(1)  Whether Mr. Chow, Ms. Kam or the management office had been invited to inspect the hole is irrelevant as far as “reasonableness” is concerned.  The main point here is that there is no dispute that the defendants did as a matter of fact instruct Mr Pun to carry out the work;

(2)  It is unreliable to look at the photograph in the trial bundle for the purpose of judging whether the hole was shallow or deep.  On the other hand, in the 1^st defendant’s witness statement, he did say that the hole was of the depth of 10cm.  This part of his evidence was not challenged by Ms Lam in court.  On the other hand, according to Mr Kan, the thickness of the floor slab between the two bathrooms was 150mm[11].  That being the case, the hole which was dug by Mr Pun must be deep enough to do the necessary inspection, because the 110mm plane of the microwave detection test was only 4cm from the floor of the Upper Bathroom;

(3)  Ms Lam’s submission that the hole was dug at the wrong location was probably made on the basis of the photograph at the bottom of page 53 of trial bundle B at which Ms Lau marked one of the leakage points at the left bottom corner (next to the wall of the store room).  However, it seems to me that Ms Lau had inadvertently marked the leakage points at the wrong place in that photograph.  This can be seen by comparing that photograph with the markings which she made on the floor plan (see the middle of page 53 of trial bundle B) and the image of the water/moisture at the 110mm plane (at page 55 of trial bundle B).  The markings on the floor plan and the said image show that the water leakage point was not at the left bottom corner but slightly to the right of the bottom middle point of the Lower Bathroom, on the side of the Master Bedroom; 

(4)  Mr Pun was not asked to find out the cause of the water seepage but whether the alleged location of seepage was really wet.  As a plumber, he should be capable to do that.

192.  I therefore do not accept Ms Lam’s arguments above.

193.  Ms Lam further reminded this court that according to the WhatsApp messages between Mr Pun and Ms Kam, Mr Pun had said that he would advise the 1^st defendant to do pond test for at least 24 hours because in his view the pond test conducted by the Joint Office might not be sufficient for detecting small seepages.  However, this was never done by the defendants.  Ms Lam also stated that Mr Pun had proposed other inspection methods such as opening up the Upper Bathroom bathtub access window, spray test and pressure test.  However, she said the 1^st defendant had unreasonably ignored these suggestions, and he only agreed to conduct a spray test on the external wall for one hour.

194.  My views on these matters are as follows:

(1)  As a matter of fact, even Ms Lau, the plaintiff’s own expert, had decided to do the pond test for one hour only on 20 June 2019, even though she was well aware that there had been various unsuccessful attempts made on the part of the Joint Office.  That being the case, there is no basis for the plaintiff to suggest now that the defendants should have allowed a longer ponding test in 2017;

(2)  Since even the experts engaged in the present case had not inspected the Upper Bathroom bathtub access window, there is no basis to say that such an inspection was necessary;

(3)  The spray test was proposed to be done at the external wall, which should be responsible by the management office and the Incorporated Owners of the Building.  Furthermore, according to the evidence of the 1^st defendant (which I accept), it was the management office which allowed spray test to be done for one hour only;

(4)  According to paragraph 15 of Mr Chow’s witness statement filed for his claim started in the Small Claims Tribunal, the pressure test was proposed to be done to the fresh water pipe.  Since the plaintiff’s case herein has nothing to do with fresh water supply, it is irrelevant to take such pressure test into consideration here.

195.  I therefore refuse to accept Ms Lam’s further arguments.

E6.     The 2017 Work

196.  By letter dated 17 July 2017, Ms Kam warned the 1^st defendant that if he failed to give a positive reply within 7 days, and engage an expert to solve the water seepage problem, she would instruct lawyers to take legal action and make a substantial claim against him.

197.  The defendants then instructed another renovation contractor (Mr Lee) to do the 2017 Work on 31 July 2017.

198.  In relation to the 2017 Work, Mr Chow stated in his witness statement that:

“47. The most profound consequence of the 2017 Work, whether intended by the Defendants or not, is the total removal/destruction of the water-proofing membrane beneath the Upper Bathroom so that it would no longer be possible to check its integrity or otherwise. I was completely unaware of this aspect of the 2017 Work as a layman until after the Second Surveyor had performed his inspection on 16^th October 2017. On the other hand, the Defendants were well aware of the findings in the First Report that the water-proofing membrane was damaged. It would be to the Defendants’ advantage if this finding cannot be substantiated by a subsequent pond test. In June 2017, Mr Pun suggested a pond test but the 1^st Defendant refused. The complete removal of the water-proofing membrane in the 2017 Work had rendered it impossible to test the integrity of the water-proofing membrane now.

48. I subsequently learned that the removal/destruction of the water-proofing membrane is a common ploy used by defendants in similar cases to evade liability by removing/destroying completely ant evidence that would reveal defects in the water-proofing membrane. They would also stop using the bathroom so that the seepage (in most cases) would stop completely, thus preventing the plaintiff from conducting further investigation or pursuing his claim.

49. The Defendants alleged that they had stopped using the Upper Bathroom for the period from 31^st July 2017 to the end of January 2018.  Even if the Defendants stopped using the Upper Bathroom during the said period, which is uncertain and denied, water seepage to the [Lower] Bathroom continued even with the prolonged fine weather conditions during the said period.”

199.  Insofar as there was any hint made by Mr Chow that the defendants had carried out the 2017 Work as a “ploy” to evade liability, I would reject that groundless allegation right away without hesitation.  The defendants had caused work to be done so as to check whether there was any seepage problem within the floor slab beneath the Upper Bathroom twice in around 3 years.  As I mentioned above, if they had discovered that there were any seepage problem in 2014, they would have instructed their contractors to remedy the problem already back then.  They did not have to deploy any “ploy” as such in 2017.  The 2017 Work must have caused them much inconvenience, not to mention the costs involved.  What the defendants did again in 2017 could not be anything but reasonable.

200.  Furthermore, if the plaintiff still complained about water seepage problem despite the fact that the defendants had stopped using the Upper Bathroom, that would only reinforce the defendants’ belief at the material time that the Upper Bathroom was not the source of the problem. The court has to assess the reasonableness of the defendants’ action by taking this into account.

E7.   The Eastwin investigation

201.  The plaintiff eventually commenced legal proceedings against the defendants in the Small Claims Tribunal on 5 December 2017. 

202.  For the purpose of that claim, the defendants engaged Eastwin Professional Consultants (“Eastwin”) to prepare an expert report.

203.  Ms Lam submitted that for the purpose of preparing that report, Eastwin only conducted a visual inspection of the Upper Bathroom and an infrared survey in the Upper Bathroom, and that that was wholly inadequate.

204.  With respect, given the fact that the Eastwin investigation was done for the purpose of preparing expert evidence to be used in court, I do not think the court should take that into account when considering whether what the defendants did was reasonable.

E8.   Conclusion

205.  It is therefore my conclusion that the defendants had acted reasonably.

F.    THE RELIEF

F1.   Injunction

206.  The plaintiff claims for the following injunction orders in the Statement of Claim against the 1^st and 2^nd defendants whether by their servants or agents or any of them:

(1)  restraining each of them from causing, allowing or continuing with the water seepage from the Upper Bathroom to the Lower Bathroom; and

(2)  requiring each of them to forthwith effect repair to the Upper Bathroom and/or take remedial action so as to stop the water seepage from the Upper Bathroom to the Lower Bathroom.

207.  Mr Lee has referred this court to the case of Chiu Hung Shun Paul & Another v So Ka Tai & Another (CACV 136/2005, unreported, 5 December 2005).  In that case, Ma CJHC (as his Lordship then was) held that:

“(1) Injunctions are an equitable remedy and as such therefore subject to equitable principles. They are to be granted only where necessary, appropriate and just. For example, where damages provide an adequate remedy, an injunction will not generally be granted. Where one is to be granted, the same principles also dictate that an injunction should not be made any wider than necessary; otherwise, for example, the party subject to the injunction may find himself in contempt of court (for this is in many ways the prime remedy for a breach) of an order that goes beyond what the party benefiting from the injunction could realistically have expected or have been entitled in the first place.

(2) In the present case, the Plaintiffs’ complaint was that of a leakage from the Defendants’ premises. The obvious remedy, in the absence of any special circumstances, was simply a mandatory injunction to effect due repairs, no more. This was precisely what the Judge ordered.

(3) I have already mentioned the aspect of a contempt of court. If a permanent injunction were to be granted as the Plaintiffs wish, the Defendants might find themselves facing contempt proceedings even when they had repaired the leakage, should another leakage occur in the future. Mr Chong submitted that if another leak did occur in the future, the Plaintiffs could only succeed on a motion for contempt if they proved a contempt beyond reasonable doubt. This was the protection, he submitted, to prevent an innocent breach from being treated as a contempt. I regret I cannot agree with this submission. The relative ease or difficulty of securing a finding of contempt is not really to the point : a party should not be subjected unnecessarily to an order with penal consequences.

(4)  […]”

208.  Mr Lee submitted that only the second limb of the injunction order (i.e. a mandatory injunction) should be made herein should the defendants are liable.

209.  Ms Lam has not argued otherwise.

210.  I accept Mr Lee’s submissions.  I would therefore only have made a mandatory injunction order even if I were satisfied that the plaintiff had successfully established liability against the defendants.

F2.     Damages

211.  The plaintiff claims against the following items of damages herein:

1)     Estimated repair and reinstatement costs of the Damaged Bathroom
i.   Insurance and protection works	$5,000.00
ii.   Demolition and clearance works	$2,365.55
iii.   Concrete and metal works	$35,881.84
iv.   Lighting installation works	$7,797.34
Sub-total:	$51,044.74
2)     Investigation costs
i.   Costs of the HKSL 2016 Report dated 8 October 2016	$15,000.00
ii.   Costs of the Silver Consultant 2017 Report dated 31 October 2017	$8,500.00
iii.   Costs of the HKSL 2018 Report dated 4 January 2019	$10,000.00
iv.   Costs of the GE Protimeter BLD 2000 mini moisture meter	$1,377.72
v.   Cost of the infra-red camera Flir One Pro Thermal Imaging Camera	$2,365.05
Sub-total:	$37,242.77

F2.1     The estimated repair and reinstatement costs

212.  The plaintiff claims $51,044.74 as the estimated repair and reinstatement costs of the Lower Bathroom.

213.  This figure was adopted from the Silver Consultants 2017 Report, in which it was explained that:

“綜合以上所有檢測結果，可推斷上層單位令勘察單位客廳、睡房天花及牆身、儲物閣仔出現滲漏情況。由以上現象可見，勘察單位內包括睡房天花燈、睡房天花及牆身、儲物閣仔損毁及受浸水破壞。而根據滲漏情況所需的損失及維修更換費用大約為: $51,044.74”

214.  It can thus be seen that Silver Consultants had taken damages caused to some other parts of the Lower Flat into account when arriving at the above figure.

215.  However, it has never been alleged herein that the damages to those other parts of the Lower Flat, including the living room, bedroom, etc., were caused by water coming from the Upper Bathroom. 

216.  I should make it clear that I have not lost sight of the fact that the plaintiff did plead in the Statement of Claim that the costs of repair claimed are costs of repair “of the ceiling of the Damaged Flat including Damaged Bathroom”.  Literally that includes ceiling of the whole Lower Flat.  However, it must be remembered that, in the Statement of Claim, only damage to the Lower Bathroom (but not anywhere else in the Lower Flat) had been alleged.  That was also the way the whole action was handled by the plaintiff’s legal team.  For example, the experts (Ms Lau and Mr Kan) had never been asked to inspect other parts of the Lower Flat other than the Lower Bathroom.

217.  I will therefore reject this claim.

218.  Instead, I will allow the sum of $16,697.6 which has been agreed by both experts to be the estimated repair costs, in respect of which Mr Lee has raised no objection.

F2.2    The investigation costs

219.  If liability had been established, I would have awarded the plaintiff with reasonable investigation costs in the total amount of $23,500 comprising:

(1)  Costs of the HKSL 2016 Report dated 8 October 2016 in the sum of $15,000; and

(2)  Costs of the Silver Consultants 2017 Report dated 31 October 2017 in the sum of $8,500.

220.  However, I would not allow the costs incurred for the HKSL 2018 Report dated 4 January 2019.  By the time when the inspection was conducted for the purpose of this report on 8 November 2018, the action herein had already been commenced.  As no leave had been granted for the obtaining of this expert report, no costs in relation thereto should be allowed.

221.  Neither am I minded to allow for the costs of the moisture meter or the infrared camera purchased by Mr Chow.  It is unnecessary for him to purchase the equipment.  I agree with Mr Lee that the data obtained by Mr Chow by virtue of those gears would not carry much weight. Further, as admitted by Mr Chow, at the end of the day, the infrared camera was not of much use to him.

G.   ORDER

222.  To conclude, although I have much sympathy on the plaintiff, I have to dismiss its action herein for the reasons explained above.

H.   COSTS

223.  I make a costs order nisi that the plaintiff shall bear the costs of the defendants, with certificate for counsel, to be taxed if not agreed.

224.  If any party wishes to vary the costs order nisi:

     i.  Such a party shall lodge and serve written submissions within 14 days hereof;

     ii.  The other party shall lodge and serve written submissions within 14 days thereafter;

     iii.  The applying party shall lodge and serve written submissions in reply within 7 days thereafter;

     iv.  The application shall then be disposed of on papers.

225.  The above order nisi shall become absolute in the absence of application to vary within the first 14-day period mentioned above.