Chiu Yi Tung v. Lo Yue Fung Franky and Another

DCCJ 3591/2019

[2023] HKDC 1117

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

CIVIL ACTION NO 3591 OF 2019

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J U D G M E N T

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A.  INTRODUCTION

1.This action concerns a water seepage claim. The plaintiff is the registered owner and occupier of Flat A, 2^nd Floor (“Flat 2A”), Tower 3 (“Building”), Parc Regal, a residential estate in Ho Man Tin, Kowloon. She claims that damage has been caused to her property by the water seepage from the flat which is situated immediately above Flat 2A, viz. Flat A, 3^rd Floor of the Building, of which the defendants are the registered owners and occupiers.

2.The plaintiff’s claims in this action mainly relate to an alleged failure by the defendants to maintain and repair the defective waterproofing layer and flush water pipe in Flat 3A, resulting in water seepage to the bedroom (“Flat 2A Bedroom”), cloakroom (“Flat 2A Cloakroom”) and maid’s bathroom (“Flat 2A Maid’s Bathroom”) of Flat 2A, which are situated immediately below the kitchen (“Flat 3A Kitchen”), master bathroom (“Flat 3A Master Bathroom”) and maid’s bathroom (“Flat 3A Maid’s Bathroom”) of Flat 3A respectively. According to the plaintiff’s case, notwithstanding that some remedial works were done at Flat 3A, those works were insufficient to abate the water seepage problem in Flat 2A since early 2015. In these proceedings, she seeks injunctive relief, as well as general and special damages, against the defendants.

3.The defendants deny the plaintiff’s claim. According to their case, the replacement of the drainage pipe of the bathtub in Flat 3A Master Bathroom in July 2018 was sufficient to address the water seepage problem complained of by the plaintiff. Further, in August 2019, viz. shortly after the plaintiff commenced these proceedings, they engaged a contractor to extensively repair and renovate Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom.

4.The plaintiff is the only factual witness of her case, while the 1^st defendant is the only factual witness of the defendants’ case. Both parties have adduced expert evidence on the issues of water seepage and quantum of damages. The plaintiff’s expert is Mr Lau Wing Wai Patrick (“Mr Lau”), and the defendants’ expert is Mr Chung Wai Hoi Vincent (“Mr Chung”).

B.  BACKGROUND

5.In this section, I set out the undisputed background facts chronologically, specifying the more major factual disputes where they appear.

6.According to the plaintiff’s case, she first discovered water seepage in the ceiling and wall of Flat 2A Bedroom in around early 2015. Shortly thereafter, in April 2015, she also observed water seepage in the ceiling of Flat 2A Cloakroom and Flat 2A Maid’s Bathroom.

7.It is common ground that, in April 2015, the plaintiff complained to the management office of Parc Regal (“Management Office”) about the water seepage problem in Flat 2A. According to the incident log prepared by the Management Office (“Incident Log”),[1] on 15 April 2015, it issued a letter to the defendants requiring them to allow the contractors engaged by the Management Office to access Flat 3A in order to repair the communal drainage pipe, but since no consensus could be reached between the Management Office and the defendants, on 11 April 2016 (viz. almost a year after the Management Office requested the defendants for access to Flat 3A), the Management Office arranged for repair works to be done to the communal drainage pipe from the external wall by erecting scaffolding from the Ground Floor to the 3^rd Floor of the Building.

8.Meanwhile, on 27 September 2015, the plaintiff reported to the Management Office that the water seepage to the ceiling of the Flat 2A Cloakroom caused short circuit to the lighting on the ceiling. As a result, the Management Office arranged a technician to terminate the power supply therein due to safety concerns.

9.After the repair works to the communal drainage pipe were completed in April 2016, it is the plaintiff’s case that the water seepage problem in Flat 2A persisted and she complained to the Management Office from time to time, although her complaints were not recorded in the Incident Log. According to the Incident Log, the Management Office received a complaint from the plaintiff on 26 May 2017 in respect of the water seepage problem in Flat 2A which remained unresolved for two years.

10.On 2 June 2017, the Joint Office for Investigation of Water Seepage Cases (“Joint Office”) set up by the Buildings Department (“BD”) and the Food and Environmental Hygiene Department (“FEHD”) and the Management Office conducted an inspection of Flat 2A, which confirmed that there was water seepage in Flat 2A Bedroom, Flat 2A Cloakroom and Flat 2A Maid’s Bathroom. The moisture content in the seepage area in Flat 2A Maid’s Bathroom was more than 35%, thus exceeding the benchmark adopted by the Joint Office for investigation of water seepage. Thereafter, on 19 June 2017, the Joint Office conducted a colour water test to the drainage inlets of Flat 3A. Further investigation was also conducted by the Joint Office in Flat 2A between 19 June 2017 and 11 August 2017.

11.According to the Incident Log, on 3 August 2017, the Management Office received a letter from the BD informing them that the BD had issued an advisory letter to the defendants to make repairs to the damaged pipe in Flat 3A Maid’s Bathroom. It is common ground that, in around October or November 2017, the defendants replaced the U-shaped drainage pipe in Flat 3A Maid’s Bathroom.

12.By letters dated 12 October 2017, the Joint Office informed the plaintiff and the defendants respectively that the colour water test done in Flat 3A on 19 June 2017 returned a negative result and did not show that the water seepage problem in Flat 2A was related to the drainage inlets in Flat 3A, but since the water seepage problem in Flat 2A persisted, professional investigation would be carried out. The Joint Office engaged Pioneer Management Limited (“Pioneer”), an independent professional investigation company, to conduct further investigation of the water seepage problem in Flat 2A.

13.Between 1 December 2017 and 9 May 2018, Pioneer conducted visual inspection, moisture content check, a colour water test for sanitary fitments, and a pond test in Flat 2A and Flat 3A. In Pioneer’s inspection report dated 28 May 2018, Pioneer opined that apparent water moisture was found in the ceiling and wall of Flat 2A Bedroom, the ceiling of Flat 2A Cloakroom and the ceiling of the guest bathroom of Flat 2A. Visual inspection of Flat 3A showed that it was in a dry condition generally. The colour water test to the drainage inlets of Flat 3A showed that leakage from the drainage pipe was uncertain. However, the ponding test done in Flat 3A showed that there was floor slab infiltration from the bathtub of Flat 3A Master Bathroom, and the same, according to Pioneer, caused water seepage to Flat 2A.

14.Based on Pioneer’s findings, the Joint Office issued letters dated 4 June 2018 to the plaintiff and the defendants respectively informing them that the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom was found to be defective and resulted in water seepage.

15.On 13 June 2018, the Management Office conducted an inspection of Flat 3A but it did not reveal the source of water seepage.

16.On 14 July 2018, the Management Office conducted another inspection of Flat 3A, during which water was found upon opening the access panel of the bathtub of Flat 3A Master Bathroom. According to the Incident Log, although it could not be ascertained if the same was the source of water seepage in Flat 2A, the defendants agreed to make repairs of this part first. The defendants informed the Management Office on 24 July 2018 that the drainage pipe in Flat 3A Master Bathroom had been replaced.

17.According to the Incident Log, the Management Office conducted an inspection of Flat 2A on 15 August 2018 and observed that the water seepage problem in Flat 2A continued.

18.On 20 November 2018, the Joint Office issued a letter and a nuisance notice (“Nuisance Notice”) to the defendants. The letter stated that:-

“In response to a complaint of water seepage, investigation has been conducted to [Flat 3A] by the Joint Office. The investigation result(s) indicate that [Flat 3A is] the source of seepage leading to an existence of a nuisance.

Attached herewith is a Nuisance Notice issued to you under section 127(1) of the Public Health and Municipal Services Ordinance, Cap. 132, you are required to comply with the requirements as specified in the Nuisance Notice to abate the nuisance.”

The Nuisance Notice reads:-

“1. Take notice that under the provisions of the Public Health and Municipal Service Ordinance, the Director of Food and Environmental Hygiene, being satisfied of the existence at [Flat 3A] of a nuisance, being water seepage from the master bathroom at the aforesaid premises to the premises below at [Flat 2A] and such seepage has rendered the aforesaid premises below in such a state as to be a nuisance do hereby require you, within 28 days from the service of this notice, to abate the nuisance, and for that purpose to repair satisfactorily the floor slab including enclosing walls of the bathtub of the master bathroom of [Flat 3A] to prevent water seepage to the premises below at [Flat 2A] and the said Director of Food and Environmental Hygiene do hereby require you within the said period to do what is necessary for preventing the recurrence of the nuisance and for this purpose to repair satisfactorily the floor slab including enclosing walls of the bathtub of the master bathroom of [Flat 3A] to prevent water seepage to the premises below at [Flat 2A].

2. If you make default in complying with the requirements of this notice (or if the said nuisance, though abated, is likely to recur) application will be made to a Magistrate’s Court for a summons to be issued requiring your attendance before such court to answer a complaint which will be made for the purpose of enforcing the abatement of the nuisance and/or prohibiting the recurrence thereof, or both, and for recovering the costs and penalties that may be incurred thereby.” (original emphasis)

19.There is no dispute that, despite the Joint Office’s letter and the Nuisance Notice, no repair works were done by the defendants in relation to the waterproofing layer in Flat 3A until late August 2019.

20.On 27 December 2018, the plaintiff requested the defendants, through the Management Office, for permission to allow her appointed expert to have access to Flat 3A and to make inspection thereat. The defendants replied that they would only allow access to Flat 3A after the Chinese New Year holidays.[2]

21.On 4 March 2019, the plaintiff again requested the defendants, through the Management Office, for permission to allow her appointed expert to have access to Flat 3A and to make inspection thereat. According to the Incident Log, the defendants replied to the Management Office that the plaintiff’s appointed expert shall make a written request and inquired if this was the last time for inspection at Flat 3A. The plaintiff replied that her appointed expert would not be able to make such a written request, and instead, the plaintiff issued a letter to the defendants for permission for access to Flat 3A. The defendants informed the Management Office that they would not accept the plaintiff’s letter and returned the same to the Management Office.

22.Upon the plaintiff’s further requests to the defendants through the Management Office, on 13 March 2019, the defendants replied to the Management Office that they could only arrange for inspection of Flat 3A in mid-June 2019. The defendants left Hong Kong for Canada to visit the 1^st defendant’s father[3] between 27 April and 13 May 2019.

23.Meanwhile, between 15 March 2019 and 9 April 2019, the plaintiff engaged Ms Lau Shan La of Hong Kong Survey Limited (“HKSL”) to conduct investigation of water seepage in Flat 2A.

24.On 1 April 2019, the Joint Office carried out a confirmatory water dye test at Flat 3A to ascertain whether the requirements stated in the Nuisance Notice had been complied with.

25.On 11 May 2019, HKSL compiled a survey report (“HKSL Report”) in which certain findings of the source of water seepage in Flat 2A were made. There is no dispute between the parties that the HKSL Report is not admissible as expert evidence in these proceedings.

26.On 18 June 2019, the plaintiff issued a pre-action letter, enclosing a copy of the HKSL Report, to the defendants.

27.By a letter dated 24 June 2019, the defendants replied to the plaintiff’s solicitors, stating that they had already undertaken repair works to the discharge pipes of Flat 3A Maid’s Bathroom and Flat 3A Master Bathroom. As for the flooring of Flat 3A Kitchen, Flat 3A Master Bathroom and the guest bathroom of Flat 3A, the defendants stated that the Joint Office, having conducted “colour liquid tests” over the past two years, did not make any further comment.

28.On 12 July 2019, the plaintiff issued the writ herein. The same was served on the defendants on 25 July 2019.

29.Thereafter, in August 2019, the parties’ respective solicitors exchanged correspondence in relation to the defendants’ proposed inspection of Flat 2A and remedial works to be done to Flat 3A. There is no dispute that the defendants commenced waterproofing works in Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom on around 23 August 2019. According to the defendants, their contractors conducted a 48-hour water test between 1 and 3 September 2019 after the waterproofing works were done. The repair and renovation works in Flat 3A were completed on 20 September 2019.

30.Meanwhile, the Joint Office informed the defendants by a letter dated 23 August 2019 that after the Nuisance Notice was issued, persistent water seepage was still observed in Flat 2A. However, since the confirmatory water dye test on 1 April 2019 returned a negative result, there was insufficient evidence to conclude that the water seepage problem in Flat 2A was due to the defendants’ non-compliance with the requirements stated in the Nuisance Notice, and thus no prosecution would be instituted against the defendants. Further, since the Joint Office and Pioneer had tried different non-invasive methods to detect water seepage but were still unable to effectively confirm the source of water seepage in Flat 2A, the Joint Office would cease investigation. The parties were advised to consider resorting to mediation or litigation to resolve their dispute arising from the water seepage problem.

C.  THE PARTIES’ PLEADED CASES

C1.  The plaintiff’s case

31.The plaintiff’s pleaded case is as follows. The water seepage problem in Flat 2A Bedroom, Flat 2A Cloakroom and Flat 2A Maid’s Bathroom was caused by defects in the waterproofing layers and pipes in Flat 3A.

32.The plaintiff avers that the defendants were made aware of the defects in Flat 3A but have failed to take appropriate steps to rectify those defects, including to ensure that the waterproofing layers of Flat 3A are properly installed and maintained, and to keep the drainage pipes in Flat 3A in a good repair and condition, and are thus liable under Clause 42 of the deed of mutual covenant of Parc Regal (“DMC”), section 34H(1) of the Building Management Ordinance (Cap 344) (“BMO”), and in negligence.

33.The plaintiff claims that, as a result of the water seepage from Flat 3A to Flat 2A, damage was caused to Flat 2A Bedroom, Flat 2A Cloakroom and Flat 2A Maid’s Bathroom. She therefore claims: (1) a mandatory injunction that the defendants shall carry out repair works to prevent further water seepage from Flat 3A to Flat 2A; (2) the costs of rectification works at $143,884; (3) the costs of substituted accommodation during repair works at $11,200; (4) the costs of general cleaning at $1,600; (5) the survey fees of HKSL at $40,000; and (6) damages for distress, discomfort and inconvenience at $100,000.

C2.  The defendants’ case

34.The defendants deny that they are liable for the water seepage problem in Flat 2A. They aver that such problem is not caused by any defects in Flat 3A. The first complaint they had ever received from the plaintiff was the pre-action letter dated 18 June 2019. Thereafter, even though the source of water seepage remained unidentified, they took a “robust approach” by carrying out extensive repair, waterproofing and renovation works in Flat 3A which they said would eliminate any possible water seepage from Flat 3A to Flat 2A.

35.§10 of the defence reads:-

“The Defendants’ stance is that for the purpose of saving time and costs, they admit liability to compensate the Plaintiff for damages attributable to water seepage from the Defendants’ Premises to the Plaintiffs’ Premises, subject to their right to dispute the quantum of the Plaintiff’s claim and the Plaintiff’s duty to mitigate. The Defendants also aver that the Plaintiff’s claim for fee of the Surveyor’s Report prepared for the purpose of establishing the Defendants’ liability ought to be part of the Plaintiff’s costs of this action, not a head of special damages.”

36.Mr Chau, counsel for the defendants, submits that §10 of the defence does not constitute an admission of “any of the elements of liability or quantum” by the defendants. The only admission made by the defendants in the defence was that they were under a duty, if they had notice, to take remedial action without unreasonable delay.

D.  THE ISSUES

37.The main issues to be resolved may be summarised as follows:-

(1)  what was and is the cause of water seepage in Flat 2A;

(2)  if the court finds that the water seepage in Flat 2A was and is caused by Flat 3A, whether the defendants should be held liable for the same;

(3)  if the defendants are liable, what reliefs should be granted to the plaintiff.

E.  CAUSE OF WATER SEEPAGE IN FLAT 2A

38.It is well established that the essence of a private nuisance is unreasonable user by a man of his land to the detriment of his neighbour. There is no absolute standard as to what amounts to a reasonable user, and what degree of interference, disturbance or annoyance amounts to a nuisance. The requirement that there must be a real interference with the comfort or convenience of living according to the standard of an average man, and the discomfort must be substantial to any person occupying the plaintiff’s premises, is satisfied where there is actual physical damage to the property, and this is routinely applied in water seepage cases: Loke Yuen Jean Tak Alice v Wong Kit Ying and Anor [2019] HKCFI 1895, §§49-51.

39.There is no presumption in law that the source of water leakage necessarily comes from the flat above the affected property. The burden rests on the plaintiff to prove, on the balance of probabilities, that the allegedly defective state of the waterproofing layers and pipes of Flat 3A caused water seepage in Flat 2A. It is not for the defendants to find out the real source of the water seepage or to prove that it did not come from their property. Where there are prima facie various possible sources of water which may have caused the water seepage suffered by the plaintiff, the key question is whether the plaintiff has succeeded in discharging her burden of proof: Hui Ling Ling v Sky Field Development Limited, HCA 35 of 2007 (8 May 2012), §23; Loke Yuen Jean Tak Alice (supra), §52.

40.Causation is a question of fact. The court, in applying the “but for” test, is not concerned to identify all possible causes, but with the effective cause of the resulting damage in order to assign responsibility for such damage: Clerk and Lindsell on Torts (23^rd ed, 2020), §2-09; applied in Loke Yuen Jean Tak Alice (supra), §§60-62.

E1.  The parties’ expert evidence

41.In the present case, Mr Lau and Mr Chung agree that the court may make reference to the Professional Guide to Water Seepage Investigation, Diagnosis, Testing and Reporting in Residential Buildings published by the Hong Kong Institute of Surveyors (“HKIS Guide”), which is an authoritative guide to the investigation of water seepage problems in Hong Kong.

42.Both experts also agree that the source of the water seepage problem in Flat 2A up to the time of the joint inspections (viz. in November and December 2019) was not due to (1) water leakage from the fresh water supply pipe(s), or (2) water seepage through the external wall.

E1a.  Mr Lau’s evidence

43.The plaintiff relies on the expert evidence of Mr Lau, a registered professional surveyor (building surveying) under the Surveyors Registration Ordinance (Cap 417). Mr Lau’s qualifications are not disputed, and I accept that Mr Lau has the relevant expertise to provide expert opinion on the cause of water seepage in the present case.

44.Mr Lau included the HKSL Report as an appendix to his expert report dated 10 February 2020 (“Mr Lau’s Report”) on the ground that it had been provided to him by the plaintiff as background information. As stated above, it is common ground that the HKSL Report is not admissible as expert evidence in these proceedings. No issue arises as to Mr Lau’s inclusion of the HKSL Report in his expert report,[4] and he has not been cross-examined on the same.

45.On the whole, I find Mr Lau’s expert evidence to be reliable. His opinion on the cause of water seepage in Flat 2A was based on scientific and empirical findings from a water sample analysis, electrical conductivity test, infrared thermographic scans, microwave scans and visual inspection conducted by himself. His opinion is also consistent with the findings made by Pioneer, the independent investigation company engaged by the Joint Office. I observed that Mr Lau fairly accepted some limitations in his evidence during cross-examination which, in my view, is a telling indicium of the professionalism and impartiality of an expert witness: cf. Chinachem Charitable Foundation Limited v Chan Chun Chuen, HCAP 8 of 2007 (2 February 2010),[5] §487, per Lam J (as Lam VP then was). For instance, he accepted that the electrical conductivity test results are unable to show the direction of water flow, that water seepage was no longer observed in Flat 2A Maid’s Bathroom, that no water was found dripping and no fluorescent effect was noticed under UV light after colour water dye test was conducted in Flat 2A Cloakroom, and that the differences observed in the photos of the drainage pipe of Flat 3A which were taken before and after the flooding test could be attributed to the fact that he had not pointed the UV light directly to the ceiling.

46.Mr Chau tries to attack Mr Lau’s expert evidence on the ground that his evidence on the interpretation of the thermographic infrared images was false. As further elaborated below, I do not find that such criticism could stand in the light of the HKIS Guide and Mr Lau’s evidence as a whole. More importantly, Mr Lau’s interpretation of the thermographic infrared images is consistent with the results of the other tests, and as both experts agreed in their evidence, all test results cannot be considered in isolation but should be considered in the light of the results of the other tests. I therefore reject Mr Chau’s submission that Mr Lau gave false evidence as alleged.

E1b.  Mr Chung’s evidence

47.The IO relies on the expert evidence of Mr Chung, a registered professional engineer under the Engineers Registration Ordinance (Cap 409). I note that Mr Chung has not provided his curriculum vitae in his expert report dated 25 February 2020 (“Mr Chung’s Report”), the joint statement dated 20 July 2020 (“Joint Statement”) or at all throughout these proceedings notwithstanding that (1) it was expressly stated to be included in Appendix VI to the Joint Statement (see §2.3 of the Joint Statement), and (2) I specifically raised this issue with Mr Chung during his oral testimony and he replied that he had forgotten to include the same in both reports, upon which Mr Yan, counsel for the plaintiff, fairly indicated that he had no objection to Mr Chung producing his curriculum vitae for the court’s consideration. It is not clear why Mr Chung still fails to produce his curriculum vitae to the court. Having said that, since Mr Chung’s qualification as a registered professional engineer is not disputed by the plaintiff, I am prepared to accept on such basis that he has the relevant expertise to provide expert opinion on the cause of water seepage in the present case.

48.Further, I find that Mr Chung did not comply with the requirements stated in Order 38, rules 37A and 37C of the Rules of the District Court (Cap 336H) (“RDC”) to (1) verify his Report by a statement of truth in accordance with Order 41A of the RDC, and (2) contain a declaration in his Report that (a) he has read the code of conduct set out in Appendix E and agrees to be bound by it, (b) he understands his duty to the Court, and (c) he has complied with and will continue to comply with that duty. But since Mr Chung, in his evidence-in-chief, confirmed under oath that the contents of his Report are true and correct, and no issue has been taken by the plaintiff on this front, I am not prepared to hold his Report to be inadmissible despite his failure to comply with Order 38, rules 37A and 37C of the RDC.

49.Nevertheless, I have reservations about the reliability of Mr Chung’s evidence. In particular, I find the following aspects of his evidence to be unsatisfactory and to have diminished the weight that can be placed on his evidence as a whole.

50.First, notwithstanding that the expert directions given by Master Rita So on 24 November 2020 provided that the experts shall address, among other things, “the source/cause of water leakage/seepage which has resulted in physical damage to the Plaintiff’s premises”, Mr Chung admitted during cross-examination that (1) he simply adopted the methodology proposed by Mr Lau without analysing whether the same was sufficient to discover the cause of water seepage in Flat 2A because it was up to the plaintiff to prove the cause of water seepage, and (2) even if the tests proposed by Mr Lau were insufficient, he would not raise any issues on his own volition because his role in these proceedings is to defend the defendants.

51.It is right to point out that the stance adopted by Mr Chung in preparing his expert opinion seems to suggest that he might have placed his duty to the defendants above his overriding duty to the court, which in turn cast doubt on the reliability of his expert evidence. As Lam J (as Lam PJ then was) explained in Chinachem Charitable Foundation Limited v Chan Chun Chuen, HCAP 8 of 2007 (2 February 2010), §§483 and 485, 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. 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.

52.Secondly, Mr Chung has included a pipe water leakage test report prepared by Mr Wong Shun Tai Stewart (“Mr Wong”) dated 13 May 2020 (“Mr Wong’s Report”), based on tests done by Mr Wong (without the presence of Mr Lau and Mr Chung) at Flat 3A on 5 May 2020, as an appendix to the Joint Statement. However, his purported inclusion of Mr Wong’s Report in the Joint Statement is unreasonable and unjustifiable because:-

(1)  the defendants have not obtained leave to adduce Mr Wong’s Report as expert evidence in these proceedings or to call Mr Wong to give oral testimony at the trial;

(2)  Mr Wong’s Report was prepared after Mr Lau and Mr Chung conducted their joint inspections at Flat 2A and Flat 3A in November and December 2019 as well as their without prejudice meeting on 18 February 2020, and therefore the experts did not have an opportunity to discuss Mr Wong’s Report during their without prejudice meeting;

(3)  Mr Chung did not explain, either in the Joint Statement or in his evidence-in-chief, why he chose to include Mr Wong’s Report as an appendix to the Joint Statement;

(4)  Mr Chung admitted during cross-examination that he did not observe how the tests were done by Mr Wong, therefore he had no knowledge of what parameters were adopted by Mr Wong and whether any temperature control was put in place by Mr Wong during the tests to eliminate temperate variation as advised in the HKIS Guide: cf. Appendix 7.2 to the HKIS Guide, Part A, item 10;

(5)  Mr Chung accepted that the pressurised pipe test done by Mr Wong:

(a)  has not been considered by either himself or Mr Lau when agreeing on the methodology to be adopted for the joint inspections;

(b)  is not usually performed to the pipework in old buildings because, according to the HKIS Guide, the test may cause the pipes to burst thereby destroying internal decorations; and

(c)  in any event, such test is only used to test potable water supply pipe rather than flush water pipe as Mr Wong did: see §(3) of Mr Wong’s Report.

For the above reasons, I rule that Mr Wong’s Report is inadmissible, and I shall not give regard to any purported reliance of Mr Wong’s Report in the defendants’ evidence or submissions which I heard de bene esse.

53.As stated above, Mr Chung has not been able to satisfactorily explain why he included Mr Wong’s Report in the Joint Statement. The fact that the defendants provided a copy of Mr Wong’s Report to him does not mean that it should therefore be included in the Joint Statement, especially when it contains new matters which the experts did not have an opportunity to discuss during their without prejudice meeting and Mr Chung himself have considerable reservations about. As Lam J said in Chinachem Charitable Foundation Limited (supra), §484, the inclusion of something the validity of which the expert himself considered doubtful inevitably undermines his credibility in the court’s assessment. 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.

54.Thirdly, Mr Chung raised for the first time during cross-examination, and sought to repeat the same in his re-examination, that the possible causes of water seepage in Flat 2A Bedroom and Cloakroom were (1) water coming from the flat above Flat 3A (viz. Flat 4A) and (2) water seeping from the communal pipe. However, these possible causes were never mentioned in his own Report or the Joint Statement, and it is not clear how they are supported by the scientific and empirical findings therein, bearing in mind that no tests were ever done by any of the experts at Flat 4A or in relation to the communal pipes during the joint inspections. Mr Chung sought to explain away his failure to mention these possible causes up till his cross-examination by referring to a sentence written by Mr Lau in the Joint Statement (in the context of addressing water seepage in Flat 2A Bedroom) as follows:-

“I do not agree that the water seepage in the Plaintiff’s Property was caused from the flat above the Defendant’s Property as [Mr Chung] did not invite me to carry out any inspection and/or in the flat above the Defendant’s Property to clarify the situation.”

55.To my mind, the above opinion expressed by Mr Lau seems to suggest that the question of whether Flat 4A was a possible cause of water seepage in Flat 2A Bedroom was floated among the experts during the without prejudice meeting, but given that Mr Chung himself did not put forward Flat 4A as a possible cause of water seepage in any of his written opinion submitted to the court, the fact that Mr Lau briefly mentioned the same in the Joint Statement cannot, in my view, assist Mr Chung. In any event, it begs the question of why Mr Chung himself did not address this matter at all in either his own Report or the Joint Statement if he considers it to be material to his expert opinion.

56.I am of the view that there is no justification for Mr Chung to belatedly raise two additional possible causes of water seepage in his cross-examination, when he is well aware that the issue of the cause of water seepage is at the heart of his expert opinion in these proceedings: see §5.1(a) of the Joint Statement. As Lam J observed in Chinachem Charitable Foundation Limited (supra), §492, 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. In my judgment, Mr Chung sought to engage in a proliferation of expert issues in his oral evidence with a view to defending the defendants’ position that they should not be held liable for the water seepage problem in Flat 2A. If there were any substance in these new issues, Mr Chung should and could have raised them in his Report, and in any event, in the Joint Statement rather than staying silent until his cross-examination.

57.Fourthly, Mr Chung sought to cast doubt on the reliability of the results of the electrical conductivity test during cross-examination by suggesting for the first time that environmental factors such as air flow, temperature and humidity would affect the test results. However, his evidence in this regard does not sit well with his acceptance that (1) the HKIS Guide does not provide that any of these environmental factors constitute limitations to an electrical conductivity test, (2) the electrical conductivity test is accepted by the BD, the FEHD, the Housing Department and the Architectural Services Department as a methodology to investigate water seepage,[6] (3) there is no evidence suggesting that any of these environmental factors affected the test results obtained during the joint inspections, and (4) the relevant test results have been verified and adopted by himself as part of his analysis in his own Report and the Joint Statement.[7] This appears to me to be yet another attempt by Mr Chung to engage in a proliferation of expert issues as smokescreen with a view to defending the defendants’ position.

58.Fifthly, in relation to the discovery of chloride in the water sample collected from the ceiling of Flat 2A Bedroom which, according to Mr Lau’s opinion, was salt water which was used as flushing water at the Building, Mr Chung sought to explain away the test result by suggesting in both his own Report and the Joint Statement that the water sample had been influenced or contaminated by rust.[8] However, after hearing Mr Lau’s oral evidence explaining that rust (or ferrous oxide) does not contain any chloride, Mr Chung finally admitted during cross-examination that iron, when oxidised, would not give rise to chloride content. However, no explanation has been given by Mr Chung as to the basis upon which he all along maintained that the water sample had been contaminated by rust until cross-examination, and why he has changed his opinion on this issue under cross-examination. If 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: Chinachem Charitable Foundation Limited (supra), §486, per Lam J.

59.Overall, I consider it necessary to take a guarded approach to Mr Chung’s evidence.

60.With the above analysis of expert evidence, I shall now turn to analyse the respective causes of water seepage in Flat 2A Bedroom, Flat 2A Cloakroom and Flat 2A Maid’s Bathroom.

E2.  Flat 2A Bedroom

61.It is common ground between Mr Lau and Mr Chung that, during the joint inspections:-

(1)  Flat 3A Kitchen, which is situated immediately above Flat 2A Bedroom, is fitted with kitchen cabinets, a sink unit and a refrigerator, with no floor drain found;

(2)  signs of some continuing water leakage or seepage were observed on the structural ceiling of Flat 2A Bedroom;

(3)  stain marks, damp patches and peeled off paint were found on the surface of the structural ceiling of Flat 2A Bedroom;

(4)  the exposed junction box with wiring mounted to the structural ceiling of Flat 2A Bedroom (“Junction Box”) was stained, with white crystals found around the Junction Box;

(5)  water drips were found on the ceiling of Flat 2A Bedroom near the Junction Box, such that a plastic bucket had to be placed underneath to collect the dripping water;

(6)  the water sample collected at the Junction Box contained chloride, suggesting that it was flush water.

62.According to Mr Lau’s opinion, it is highly likely that the water seepage problem in Flat 2A Bedroom was and is caused by (1) water leakage of the concealed flush water supply pipes of Flat 3A, and (2) water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Kitchen. Mr Chung, whilst accepting that Flat 2A Bedroom has suffered and still suffers from “some minor water seepage problem”, opines that there is no evidence to prove that such water seepage originated from Flat 3A.

63.First, I agree with Mr Lau’s opinion, which has since been accepted by Mr Chung during cross-examination, that the discovery of chloride in the water sample collected in Flat 2A Bedroom suggests that the water dripping from the ceiling of Flat 2A Bedroom is highly likely to be salt water which was used as flush water at the Building.

64.Mr Lau also opines that the white crystals around the Junction Box of Flat 2A Bedroom were likely salt coming from the flush water supply pipes of Flat 3A. Mr Chung disagrees on the ground that no flush water supply or discharge pipes pass through Flat 3A Kitchen.

65.During cross-examination, both experts accept that the plumbing plan of Flat 3A is not available to them and thus neither of them knows exactly how the flush water supply pipes pass through Flat 3A. Nonetheless, Mr Lau has pointed out that it is more likely than not that the flush water supply pipes in Flat 3A, serving both Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom, would have passed through Flat 3A Kitchen because Flat 3A Kitchen is situated along the two most direct routes between Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom. Mr Chung, whilst making the point that the flush water supply pipes unlikely pass through the floor slabs of Flat 3A, accepts that they likely go through the walls of Flat 3A Kitchen.

66.Based on the above expert opinion on the possible routing of the flush water supply pipe in Flat 3A, I am satisfied on the balance of probabilities that the flush water pipe in Flat 3A probably passes through Flat 3A Kitchen. In the absence of any suggestion by the experts in the Joint Statement that the salt water collected at the Junction Box of Flat 2A Bedroom comes from the flush water supply pipe of another flat or the communal flush water pipe, it is more likely than not that the source of such salt water is the flush water supply pipe of Flat 3A which passes through Flat 3A Kitchen.

67.I am also satisfied on the balance of probabilities that the white crystals discovered around the Junction Box of Flat 2A Bedroom, where salt water was collected, are probably salt, and the existence of salt supports Mr Lau’s opinion that the source of water seepage in Flat 2A Bedroom is more likely than not to be the flush water supply pipe of Flat 3A which passes through Flat 3A Kitchen.

68.Turning to the electrical conductivity test conducted on the ceiling of Flat 2A Bedroom, which results were agreed by both experts, I find that those results support Mr Lau’s opinion that active water seepage was detected in Flat 2A Bedroom at the time of the joint inspections and the cause of such water seepage is more likely than not to be Flat 3A because:-

(1)  the average moisture content of the 50 test points on the ceiling of Flat 2A Bedroom increased from 20.6% to 22.4% after a ponding test which involved the flooding of the floor of Flat 3A Kitchen was conducted;

(2)  out of the 50 test points, the moisture content of 36 test points increased after the ponding test;

(3)  in particular, the moisture content of point 1 increased from 82.2% to 99.9%, which is the highest reading detectable by the protimeter used for the electrical conductivity test;

(4)  the moisture content of four test points after the ponding test was above 35%, which exceeds the benchmark adopted by the Joint Office for investigation of water seepage.

69.According to Mr Lau’s opinion, the increase in moisture content of the ceiling of Flat 2A Bedroom after the ponding test can be explained by the absence[9] or failure of the waterproofing layer in Flat 3A, causing water to flow through the weak points in the floor slabs of Flat 3A and move downwards to the ceiling of Flat 2A Bedroom. Had the waterproofing layer in Flat 3A been intact, it would have served as an aquarium to contain the water used in the ponding test within the confines of the four walls and floor of Flat 3A and to prevent the same from flowing elsewhere in the Building, including to Flat 2A. Mr Chung agreed in cross-examination that, generally speaking, if a waterproofing layer is defective and has cracks, it would cause water to move in all directions during a ponding test.

70.I am of the view that Mr Lau’s opinion in this respect is reasonable and accords with the explanation given in the HKIS Guide as to the movement of water, which can be horizontal, vertically downwards, or even upwards, as it is aided by gravity or capillary action: see §2.1 of the HKIS Guide. In particular, his aquarium analogy of a sound waterproofing layer is consistent with the requirement laid down by the Joint Office in the Nuisance Notice that the defendants shall “repair satisfactorily the floor slab including enclosing walls of the bathtub” (emphasis added) of Flat 3A Master Bathroom, which seems to me to suggest that a waterproofing layer, in order to be effective, should be put in place not only in the floor slab but also in the enclosing walls so as to contain the water within the confines of Flat 3A.

71.In the Joint Statement, Mr Chung stated that the water dripping from the ceiling of Flat 2A Bedroom is unlikely originated from Flat 3A because (1) during the joint inspections, the washing machine, toilet and drain hole in the maid’s room and Flat 3A Maid’s Bathroom were situated away from the area of water seepage on the ceiling of Flat 2A Bedroom; and (2) the moisture content readings taken between these two areas were relatively dry at 9% to 25% with no water dripping. In my view, this part of Mr Chung’s opinion does not take into account the undisputed fact that water can move horizontally: see §2.1 of the HKIS Guide. During cross-examination, Mr Chung accepts as a general proposition that if there is a horizontal crack in the floor slabs, water can flow through such horizontal crack to other places away from the source of water seepage. Therefore, even based on Mr Chung’s evidence, one cannot conclude that the water seepage in the ceiling of Flat 2A Bedroom is not originated from Flat 3A simply because the washing machine, toilet and drain hole in the maid’s room and Flat 3A Maid’s Bathroom were situated away from the area of water seepage in Flat 2A.

72.As for the thermographic infrared scans of the ceiling of Flat 2A Bedroom, Mr Lau and Mr Chung took their respective infrared images during the joint inspections, based on which they have given different interpretations of those images in support of their respective opinion on the cause of water seepage in Flat 2A Bedroom. My views on the thermographic infrared scans are as follows.

73.First, the infrared images taken by Mr Lau before and after the ponding test show that the blue area is significantly larger after the test. According to Mr Lau’s opinion, this shows that the temperature measured on the ceiling of Flat 2A Bedroom was lower after the ponding test, suggesting that there is an increase in dampness of the ceiling.

74.On the other hand, the infrared images taken by Mr Chung before and after the ponding test show that the area remained green both before and after the test, suggesting that there is no significant difference in the temperature, and thus dampness, of the ceiling of Flat 2A Bedroom.

75.In my view, it is not easy to reconcile the differences in the infrared images taken by both experts at the same area and at around the same time. Nonetheless, I note that both experts agreed in their evidence that all test results cannot be considered in isolation but should be considered in the light of the results of the other tests. On such basis, it seems to me that the infrared images taken by Mr Chung, which show no significant difference in dampness in the ceiling of Flat 2A Bedroom before and after the ponding test, do not sit well with the agreed electrical conductivity test results showing that the average moisture content on the ceiling of Flat 2A Bedroom increased from 20.6% to 22.4% after the ponding test, as well as the other test results (to be further discussed below). In my view, on balance, Mr Lau’s infrared images are more consistent with the agreed results of the electrical conductivity test, and I would prefer the same over Mr Chung’s infrared images.

76.According to the opinion of both experts, if the waterproofing layer is sound, it would serve as an aquarium to contain the water used in a ponding test, and thus the infrared images taken before and after the ponding test should be more or less the same. Thus, the increase in dampness in the ceiling of Flat 2A Bedroom after a ponding test is done in Flat 3A Kitchen, as shown in Mr Lau’s infrared images, would suggest that the waterproofing layer in Flat 3A Kitchen is more probable than not to be defective, thus causing water used in the ponding test to flow into the ceiling of Flat 2A Bedroom.

77.Secondly, the defendants take issue of Mr Lau’s interpretation of the infrared images, and in particular, his oral evidence that the same colour on the infrared images indicates the same temperature, on the ground that the bar on the right hand side of those images, known as the spectrum (“Spectrum”), was different before and after the ponding test. According to Mr Chau’s submission, if the two Spectrums were to be divided into equal intervals by way of linear scaling, it would show that the same colour does not indicate the same temperature, and therefore Mr Lau’s evidence is demonstrably false.

78.I note that this point was only raised in the defendants’ closing submissions. It is pertinent to note that the gist of Mr Lau’s oral testimony is that one should primarily look at the “overall trend” of the infrared images, rather than the Spectrum, to ascertain if there is any change in the temperature of the structure examined over time. His evidence in this regard is amply supported by §4.2.2 of the HKIS Guide, stating, among other things, that:-

“The temperature difference should be clearly demonstrated by variations in the colour of the digital images of the parts of the structure examined. The process is essentially comparative and should not be considered capable of giving absolute values of moisture”.[10]

This commentary of the characteristics of an infrared thermographic scan in the HKIS Guide makes it clear that:-

(1)  the comparative exercise is done by way of comparing the variations in the colour of the digital images; and

(2)  the images do not give absolute values of moisture but only qualitative (as opposed to quantitative) data.[11]

79.For the above reasons, it seems to me that the argument raised by the defendants in relation to the Spectrum is very much a red herring. On the whole of the evidence, I do not accept the defendants’ criticism of Mr Lau’s interpretation of the infrared images on the ground of the Spectrum.

80.Thirdly, it is Mr Chung’s evidence that, after both himself and Mr Lau conducted their respective infrared scans in respect of Flat 2A Bedroom, his team asked Mr Lau’s team whether they observed any difference in temperature that suggested any significant increase in dampness, and their answer was negative. On the other hand, Mr Lau denies to have any knowledge of such alleged conversation.

81.In my view, Mr Chung’s claim in this regard, even taken at its highest, would not have affected the veracity of Mr Lau’s infrared images because:-

(1)  No issue has been raised as to the authenticity of the infrared images taken by Mr Lau during the joint inspections.

(2)  Mr Chung has never identified the persons involved in the alleged conversation. No witness with direct knowledge of such conversation has come forward to give evidence on the same.

(3)  During cross-examination, Mr Chung accepts that he himself did not have any communication with Mr Lau during the joint inspections as to their respective infrared images. Therefore, he did not verify with Mr Lau at the spot whether there was any difference in their respective infrared images.

(4)  According to §4.2.2 of the HKIS Guide, infrared images “must be interpreted by experienced professionals” and “may be processed by specialised software to provide further off-site analysis along with a graphics package to display or print the results”, whilst the “specification and calibration record of the equipment shall be submitted to the project officer for approval and inspection”.

(5)  Therefore, the interpretation of infrared images is not simply a matter of comparing the raw data obtained at the spot as Mr Chung seems to suggest, but requires detailed analysis by an experienced professional with reference to the specification and calibration record of the equipment. Further processing by specialised software may also be required.

In the premises, on balance, I do not think that Mr Chung’s evidence on the alleged conversation is substantiated, but even if it did, it would not have affected the veracity of Mr Lau’s infrared images.

82.Turning then to the microwave leakage detection scans performed by Mr Lau and Mr Chung at the ceiling of Flat 2A Bedroom, they took their respective microwave scan images during the joint inspections, based on which they have given different interpretations of those images in support of their respective opinion on the cause of water seepage in Flat 2A Bedroom. My views on the microwave scans are as follows.

83.First, the microwave scan images taken by Mr Lau before and after the ponding test show that the distribution of moisture content changed at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Bedroom. Also, the moisture content at the depth of 30 mm (viz. the level closest to the ceiling surface of Flat 2A Bedroom) generally increased.

84.As for the microwave scan images taken by Mr Chung before and after the ponding test, they also show that the distribution of moisture content changed at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Bedroom. Having compared the images taken by Mr Chung, I do not accept his opinion in the Joint Statement that “the Microwave Scan results before and after the water tests show no obvious changes or diffusion of moisture content at the depth of 30mm, 70mm and 110mm”.[12]

85.In my view, it is significant that the moisture content distribution at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Bedroom changed after a ponding test is performed at Flat 3A Kitchen. According to the opinion of both experts, if the waterproofing layer is sound, it would serve as an aquarium to contain the water used in the ponding test, and thus the microwave scan images taken before and after the test should be more or less the same. On such basis, the change in moisture content in the ceiling of Flat 2A Bedroom after a ponding test is done in Flat 3A Kitchen would suggest that the waterproofing layer in Flat 3A Kitchen is more probable than not to be defective, thus causing water used in the ponding test to flow through the floor slabs of Flat 3A downwards into the ceiling of Flat 2A Bedroom at different levels.

86.Insofar as the microwave scan images taken by both experts showing different levels of moisture content before and after the ponding test, I bear in mind that all test results should be considered in the light of the results of the other tests: see §75 above. On such basis, it seems to me that the microwave scan images taken by Mr Chung, which show no significant difference in dampness in the ceiling of Flat 2A Bedroom before and after the ponding test, does not sit well with the agreed electrical conductivity test results showing that the average moisture content on the ceiling of Flat 2A Bedroom increased from 20.6% to 22.4% after the ponding test. In my view, on balance, Mr Lau’s microwave scan images are more consistent with the agreed results of the electrical conductivity test, and I would prefer the same over Mr Chung’s microwave scan images.

87.Secondly, it is Mr Chung’s evidence that, after both himself and Mr Lau conducted their respective microwave scans in respect of Flat 2A Bedroom, his team asked Mr Lau’s team whether they observed any difference in index readings that suggested any significant increase in dampness, and their answer was negative. On the other hand, Mr Lau denies to have any knowledge of such alleged conversation.

88.In my view, Mr Chung’s claim in this regard, even taken at its highest, would not have affected the veracity of Mr Lau’s microwave scan images because:-

(1)  No issue has been raised as to the authenticity of the microwave scan images taken by Mr Lau during the joint inspections.

(2)  Mr Chung has never identified the persons involved in the alleged conversation. No witness with direct knowledge of such conversation has come forward to give evidence on the same.

(3)  During cross-examination, Mr Chung accepts that he himself did not have any communication with Mr Lau during the joint inspections as to their respective microwave scan images. Therefore, he did not verify with Mr Lau at the spot whether there was any difference in their respective microwave scan images.

(4)  According to §4.2.5 of the HKIS Guide, “[i]nterpretation of the data in the form of the wet weight moisture so taken … requires experienced personnel”.

(5)  Therefore, the interpretation of microwave scan images is not simply a matter of comparing the raw data obtained at the spot as Mr Chung seems to suggest, but requires detailed analysis by experienced personnel.

(6)  Indeed, it is Mr Chung’s opinion in the Joint Statement that “an overall picture showing relative moisture distributions could only [be] obtained when the indices were fed into the computer in the office”.[13] This, in my view, is tantamount to an admission that an off-site analysis is required for a proper interpretation of microwave scan images.

In the premises, on balance, I do not think that Mr Chung’s evidence on the alleged conversation is substantiated, but even if it did, it would not have affected the veracity of Mr Lau’s microwave scan images.

89.Thirdly, Mr Chung raised an issue in the Joint Statement that the microwave scan images do not show any signs which indicate that there was seepage moving from Flat 3A Maid’s Bathroom to the direction of Flat 2A Bedroom. It seems to me that Mr Chung puts undue emphasis on Flat 3A Maid’s Bathroom by assuming that it is the only possible cause of water seepage in Flat 2A, without addressing the likely causes of flush water supply pipes and defective waterproofing layer of Flat 3A as suggested by Mr Lau.

90.For completeness, the experts also conducted a colour dye test in Flat 2A Bedroom during the joint inspections, which returned a negative result. According to §4.2.1 of the HKIS Guide, a failure to record the presence of dye colour after a dye test is performed in the damp zone cannot be taken as definite evidence against the suspected source, and the test is “weak in showing the colouring effect without surface cracks, such as embedded waterproofing membrane defects”. There is also no suggestion by Mr Chung that such test result is conclusive. In the circumstances, I consider that the negative result of the colour dye test done in Flat 2A Bedroom is only one of the matters, which is by no means determinative, that I should take into consideration in determining the cause of water seepage in Flat 2A Bedroom.

91.On the whole of the scientific test results and analysis performed by both experts as discussed above, I find that it is more probable than not that the water seepage problem in Flat 2A Bedroom was and is caused by (1) water leakage of the concealed flush water supply pipes of Flat 3A, and (2) water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Kitchen, as opined by Mr Lau.

E3.  Flat 2A Cloakroom

92.It is common ground between Mr Lau and Mr Chung that, during the joint inspections:-

(1)  the only pipe duct in the entire Flat 3A, which housed the drainage pipes and flush water supply pipe of Flat 3A, was found to be located in Flat 3A Master Bathroom, which is situated immediately above Flat 2A Cloakroom;

(2)  the original bathtub in Flat 3A Master Bathroom was found to have become a shower tray with a sliding glass door;

(3)  signs of some continuing water leakage or seepage were observed on the structural ceiling of Flat 2A Cloakroom;

(4)  stain marks, damp patches and peeled off paint were found on the ceiling and high-level beam of Flat 2A Cloakroom;

(5)  the lighting on the false ceiling of Flat 2A Cloakroom had been uninstalled;

(6)  there were stain marks on the timber floor finishes of Flat 2A Cloakroom.

93.According to Mr Lau’s opinion, the water seepage problem in Flat 2A Cloakroom is highly likely caused by water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Master Bathroom. Mr Chung, whilst accepting that signs of some continuing water seepage are observed on the ceiling of Flat 2A Cloakroom, opines that there is no evidence to prove that such water seepage continued to come from Flat 3A Master Bathroom.

94.First, the electrical conductivity test conducted on the ceiling of Flat 2A Cloakroom, which results were agreed by both experts, shows that active water seepage was detected in Flat 2A Cloakroom at the time of the joint inspections and the cause of such water seepage is more likely than not to be Flat 3A because:-

(1)  the average moisture content of the 25 test points on the ceiling of Flat 2A Bedroom increased from 25.4% to 26.5% after a ponding test which involved the flooding of the floor of Flat 3A Master Bathroom was conducted;

(2)  out of the 25 test points, the moisture content of 15 test points increased after the ponding test;

(3)  the moisture content of five test points after the ponding test was above 35%, which exceeds the benchmark adopted by the Joint Office for investigation of water seepage.

95.I agree with Mr Lau’s opinion that the increase in moisture content of the ceiling of Flat 2A Cloakroom after the ponding test can be explained by the failure of the waterproofing layer in Flat 3A Master Bathroom. If the waterproofing layer in Flat 3A Master Bathroom were intact, there should not have been any increase in the moisture content of the ceiling of Flat 2A Cloakroom after the ponding test. I also repeat my observations at §§69-70 above as to the importance of a waterproofing layer in preventing water from flowing elsewhere in the building.

96.In the Joint Statement, Mr Chung pointed out that the moisture content at points 9, 21 and 24 after the ponding test was less than 35%, and that there was no significant increase in the moisture content at other points. In my view, it is not clear why Mr Chung focused on points 9, 21 and 24 whilst disregarding the undisputed fact that the moisture content at points 13, 14, 18, 19 and 23 was above 35%. It is also incorrect to state that there is no significant increase in the moisture content at other points: for instance, the moisture content at point 13 increased from 37.6% to 49.3%, whilst the same at point 19 increased from 31.1% to 37.0%. For the above reasons, I do not accept Mr Chung’s opinion on the results of the electrical conductivity test.

97.Turning to the thermographic infrared scans of the ceiling of Flat 2A Cloakroom, my views are as follows.

98.First, the infrared images taken by Mr Lau before and after the ponding test show that the blue area is significantly larger after the test. According to Mr Lau’s opinion, this shows that the temperature measured on the ceiling of Flat 2A Cloakroom was lower after the ponding test, suggesting that there is an increase in dampness of the ceiling.

99.On the other hand, the infrared images taken by Mr Chung before and after the ponding test show that the area remained green both before and after the test, suggesting that there is no difference in the temperature, and thus dampness, of the ceiling of Flat 2A Cloakroom.

100.Again, I find that the infrared images taken by Mr Chung and his opinion on the same do not sit well with the agreed electrical conductivity test results showing that the average moisture content on the ceiling of Flat 2A Cloakroom increased from 25.4% to 26.5% after the ponding test. It is right to point out that the increase is relatively small, but such increase cannot be said to be de minimis. On balance, Mr Lau’s infrared images are more consistent with the agreed results of the electrical conductivity test, and I would prefer the same over Mr Chung’s infrared images.

101.In my view, the increase in dampness in the ceiling of Flat 2A Cloakroom after a ponding test is done in Flat 3A Master Bathroom, as shown in Mr Lau’s infrared images, would suggest that the waterproofing layer in Flat 3A Master Bathroom is more probable than not to be defective, thus causing water used in the ponding test to flow into the ceiling of Flat 2A Cloakroom.

102.Secondly, it is Mr Chung’s evidence that, after both himself and Mr Lau conducted their respective infrared scans in respect of Flat 2A Cloakroom, his team asked Mr Lau’s team whether they observed any difference in temperature that suggested any significant increase in dampness, and their answer was negative. On the other hand, Mr Lau denies to have any knowledge of such alleged conversation.

103.For the same reasons as stated at §81 above, I do not think that Mr Chung’s evidence on the alleged conversation is substantiated on the balance of probabilities, but even if it did, it would not have affected the veracity of Mr Lau’s infrared images.

104.As for the microwave scan images taken by the experts at the ceiling of Flat 2A Cloakroom, my views are as follows.

105.The microwave scan images taken by Mr Lau before and after the ponding test show that the distribution of moisture content changed at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Cloakroom. Also, the moisture content at the depth of 110 mm (viz. the level closest to the floor slab of Flat 3A Master Bathroom) generally increased.

106.As for the microwave scan images taken by Mr Chung before and after the ponding test, they also show that the distribution of moisture content changed at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Cloakroom. Also, the moisture content at the depth of 30 mm (viz. the level closest to the ceiling surface of Flat 2A Cloakroom) generally increased as evidenced by a larger area in dark blue. Having compared the images taken by Mr Chung, I do not accept his opinion in the Joint Statement that “I do not observed [sic] any relatively higher moisture content before and after the Color Water Dye test at the Defendant’s [sic] Property”.[14]

107.In my view, it is significant that the moisture content distribution at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Cloakroom changed after a ponding test is performed at Flat 3A Master Bathroom. I repeat my observations as stated at §85 above, based on which I am of the view that the change in moisture content in the ceiling of Flat 2A Cloakroom after a ponding test is done in Flat 3A Master Bathroom would suggest that the waterproofing layer in Flat 3A Master Bathroom is more probable than not to be defective, thus causing water used in the ponding test to flow through the floor slabs of Flat 3A downwards into the ceiling of Flat 2A Cloakroom at different levels.

108.Insofar as the microwave scan images taken by both experts showing different levels of moisture content before and after the ponding test, suffice it to say that they have both captured images showing that the moisture content generally increased at the respective depth of 110 mm (in Mr Lau’s images) and 30 mm (in Mr Chung’s images) after a ponding test is done in Flat 3A Master Bathroom. This, in my view, suggests that the waterproofing layer in Flat 3A Master Bathroom is more probable than not to be defective, thus causing water used in the ponding test to flow through the floor slabs of Flat 3A downwards into the ceiling of Flat 2A Cloakroom at different levels.

109.Mr Chung also raises an issue that, after both himself and Mr Lau conducted their respective microwave scans in respect of Flat 2A Cloakroom, his team asked Mr Lau’s team whether they observed any difference in index readings that suggested any significant increase in dampness, and their answer was negative. On the other hand, Mr Lau denies to have any knowledge of such alleged conversation.

110.Again, for the same reasons as stated at §88 above, I do not accept that the alleged conversation took place on the balance of probabilities, but even if it did, it would not have affected the veracity of Mr Lau’s microwave scan images.

111.For completeness, the experts also conducted a colour dye test in Flat 2A Cloakroom during the joint inspections, which returned a negative result. I repeat my observations on the characteristics of a colour dye test at §90 above, based on which I consider that the negative result of the colour dye test done in Flat 2A Cloakroom is only one of the matters, which is by no means determinative, that I should take into consideration in determining the cause of water seepage in Flat 2A Cloakroom.

112.On the whole of the scientific test results and analysis performed by both experts as discussed above, I find that it is more probable than not that the water seepage problem in Flat 2A Cloakroom was and is caused by water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Master Bathroom, as opined by Mr Lau.

E4.  Flat 2A Maid’s Bathroom

113.It is common ground between Mr Lau and Mr Chung that, during the joint inspections:-

(1)  water leakage was found at the bottom of the exposed drainage pipe located below the wash-hand basin and above the floor of Flat 3A Maid’s Bathroom, which is situated immediately above Flat 2A Maid’s Bathroom;

(2)  water seepage had previously existed in the structural ceiling of Flat 2A Maid’s Bathroom but was no longer observed;

(3)  stain marks, damp patches and peeled off paint were found on the surface of the structural ceiling of Flat 2A Maid’s Bathroom;

(4)  the lighting on the false ceiling of Flat 2A Maid’s Bathroom had been uninstalled.

114.According to Mr Lau’s opinion, it is highly likely that the water seepage problem in Flat 2A Maid’s Bathroom was caused by (1) water leakage of the drainage pipe of the hand-wash basin of Flat 3A Maid’s Bathroom, and (2) water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Maid’s Bathroom. Mr Chung opines that the concealed communal drainage pipes inside the pipe duct could be a source of such water seepage.

115.Mr Chung’s opinion that the concealed communal drainage pipes inside the pipe duct could be a source of the water seepage in Flat 2A Maid’s Bathroom is based on his observation that paint peels were seen on the ceiling of Flat 2A Maid’s Bathroom near the pipe duct. According to his opinion, this indicates that there was probably water seepage from the communal drainage pipes inside the pipe duct. Mr Lau disagrees on the ground that there is no sign of water stain mark on the exposed communal soil and waste pipeline and the adjoining soffit of the ceiling of Flat 2A Maid’s Bathroom.

116.In my view, the fact that paint steels were seen on the ceiling of Flat 2A Maid’s Bathroom near the pipe duct does not necessarily mean that there was water seepage from the communal drainage pipes inside the pipe duct, because the pipe duct, according to both experts, houses not only communal drainage pipes but also all other pipes servicing the same flat. No satisfactory explanation has been given by Mr Chung as to why he singled out the communal drainage pipes as a possible source without also considering the possibility of seepage from other pipes. This casts doubt as to his independence and impartiality as an expert witness because it appears likely that he has placed his duty to the defendants above his overriding duty to assist the court in ascertaining the cause(s) of water seepage in Flat 2A: see §§50-51 above.

117.Having said that, Mr Chung has accepted during cross-examination that the photos taken by Mr Lau during the joint inspections show that the pipe duct of Flat 2A was dry and clean and without any signs of decay. To my mind, it is unlikely that the pipe duct of Flat 2A would remain dry and clean if there was water seepage from the communal drainage pipes which pass through the pipe duct. I therefore do not accept Mr Chung’s opinion that there was water seepage from the communal drainage pipes inside the pipe duct or that the same (if any) constituted a cause of water seepage in Flat 2A Maid’s Bathroom.

118.Turning to the electrical conductivity test conducted on the ceiling of Flat 2A Maid’s Bathroom, which results were agreed by both experts, I find that those results support Mr Lau’s opinion that the cause of water seepage in Flat 2A Maid’s Bathroom is more likely than not to be Flat 3A Maid’s Bathroom because:-

(1)  the average moisture content of the 30 test points on the ceiling of Flat 2A Maid’s Bathroom increased from 17.5% to 22.0% after a ponding test which involved the flooding of the floor of Flat 3A Maid’s Bathroom was conducted;

(2)  out of the 30 test points, the moisture content of 28 test points increased after the ponding test;

(3)  in particular, there was a significant increase in the moisture content at points 11 (from 8.5% to 21.0%), 13 (from 18.1% to 32.7%), 15 (from 13.6% to 20.8%), 18 (from 18.9% to 24.7%), 19 (from 13.8% to 29.9%), 24 (from 18.1% to 23.6%), 26 (from 17.6% to 22.4%) and 29 (from 19.2% to 25.7%).

119.Whilst none of the test points returned a reading above 35% after the ponding test, which means that there was no active water seepage in Flat 2A Maid’s Bathroom at the time of the joint inspections, the increase in moisture content of 28 out of 30 test points after the ponding test is, in my view, nonetheless significant in that it supports Mr Lau’s opinion that the waterproofing layer of Flat 3A Maid’s Bathroom is defective for failing to contain the water used in the ponding test within Flat 3A: see §§69-70 and 95 above.

120.In the premises, I do not accept Mr Chung’s opinion that the water leakage found at the bottom of the exposed drainage pipe located below the hand-wash basin in Flat 3A Maid’s Bathroom is “very minor” and “would not cause influences to the Plaintiff’s Property”[15] because his opinion is based on an assumption that “there was the water proofing facilities [sic]” and “as long as the respective waterproofing function was in proper condition”.[16] Since his assumption that the waterproofing layer in Flat 3A Maid’s Bathroom does not stand in the light of the undisputed results of the electrical conductivity test, it follows that his opinion as to the effect of water leakage found in Flat 3A Maid’s Bathroom cannot be substantiated.

121.Nor can Mr Chung’s reliance on the fact that Flat 3A Maid’s Bathroom was newly renovated at the time of the joint inspections assist his opinion in this regard. This is because, according to his own evidence, the water leakage found in Flat 3A Maid’s Bathroom during the joint inspections can be eliminated by having “the bottle trap tightly screwed and sealed”,[17] which gives rise to questions as to why the bottle trap underneath the hand-wash basin in the newly renovated Flat 3A Maid’s Bathroom was not tightly screwed and sealed, thus in resulting visible water leakage at the time of the joint inspections. This, in my view, raises more questions than answers as to whether the “major works” allegedly undertaken by the defendants in Flat 3A after the commencement of these proceedings were effective in abating the water seepage problem.

122.As for the thermographic infrared scans taken on the ceiling of Flat 2A Maid’s Bathroom, I am of the view that the scan images respectively taken by Mr Lau and Mr Chung are insufficient to show that there was water seepage from Flat 3A Maid’s Bathroom to Flat 2A Maid’s Bathroom. I therefore do not give weight to the results of the thermographic infrared scans in assessing the cause(s) of water seepage in Flat 2A Maid’s Bathroom.

123.On the other hand, I am of the view that the microwave scan images taken by Mr Lau at the ceiling of Flat 2A Maid’s Bathroom before and after the ponding test show that the distribution of moisture content changed at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Maid’s Bathroom. Also, the moisture content at the depth of 30 mm and 110 mm generally increased.

124.As for the microwave scan images taken by Mr Chung before and after the ponding test, they also show that the distribution of moisture content changed at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Bedroom. Having compared the images taken by Mr Chung, I do not accept his opinion in the Joint Statement that “[t]he Microwave Scan results before and after the water tests show no obvious changes or diffusion of moisture content at the depth of 30mm, 70mm and 110mm”.[18]

125.In my view, it is significant that the moisture content distribution at the depth of 30 mm, 70 mm and 110 mm from the ceiling surface of Flat 2A Maid’s Bathroom changed after a ponding test is performed at Flat 3A Maid’s Bathroom. I repeat my observations as stated at §85 above, based on which I am of the view that the change in moisture content in the ceiling of Flat 2A Maid’s Bathroom after a ponding test is done in Flat 3A Maid’s Bathroom would suggest that the waterproofing layer in Flat 3A Maid’s Bathroom is more probable than not to be defective, thus causing water used in the ponding test to flow through the floor slabs of Flat 3A downwards into the ceiling of Flat 2A Cloakroom at different levels.

126.Mr Chung also raises an issue that, after both himself and Mr Lau conducted their respective microwave scans in respect of Flat 2A Maid’s Bathroom, his team asked Mr Lau’s team whether they observed any difference in index readings that suggested any significant increase in dampness, and their answer was negative. On the other hand, Mr Lau denies to have any knowledge of such alleged conversation.

127.Again, for the same reasons as stated at §88 above, I do not accept that the alleged conversation took place on the balance of probabilities, but even if it did, it would not have affected the veracity of Mr Lau’s microwave scan images.

128.On the whole of the scientific test results and analysis performed by both experts as discussed above, I find that it is more probable than not that the water seepage problem in Flat 2A Maid’s Bathroom was caused by (1) water leakage of the drainage pipe of the hand-wash basin of Flat 3A Maid’s Bathroom, and (2) water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Maid’s Bathroom, as opined by Mr Lau.

E5.  Summary

129.In summary, I find that it is more probable than not that the water seepage problem in:-

(1)  Flat 2A Bedroom was and is caused by (a) water leakage of the concealed flush water supply pipes of Flat 3A, and (b) water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Kitchen;

(2)  Flat 2A Cloakroom was and is caused by water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Master Bathroom; and

(3)  Flat 2A Maid’s Bathroom was caused by (a) water leakage of the drainage pipe of the hand-wash basin of Flat 3A Maid’s Bathroom, and (b) water seepage through the floor slab due to the failure of waterproofing layer of Flat 3A Maid’s Bathroom.

130.In the premises, I find that the plaintiff has established, on the balance of probabilities, that the water seepage problem in Flat 2A was and is caused by the defective state of Flat 3A.

F.  WHETHER THE DEFENDANTS ARE LIABLE FOR WATER SEEPAGE IN FLAT 2A

F1.  Whether the defendants made any admission of liability in the defence

131.Mr Chau, citing Wingames Investments Ltd v Mascot Land Ltd [2013] 1 HKLRD 26, argues that §10 of the defence does not amount to a clear and unequivocal admission of liability by the defendants. According to his submission, when the defence is read as a whole, it is clear that the defendants have not made any admission of any of the elements of liability or quantum because (1) they expressly deny that they were and are in breach of the covenants of the DMC or any statutory duty under the BMO, or that they caused, permitted or allowed water seepage from Flat 3A to Flat 2A;[19] and (2) they do not admit that the water seepage problem in Flat 2A was caused by their negligence.[20]

132.I agree that, as a matter of principle, in order for judgment to be given on admissions, the admissions in question must be clear and unambiguous in the context of the entire pleading as a whole: Wingames (supra), §§16, 21 and 24, per Barma JA.

133.On the other hand, I do not agree with Mr Chau’s submission that §10 of the defence does not contain any admission of any of the elements of liability or quantum. His submission is tantamount to suggesting that the plea that “[the defendants] admit liability to compensate the Plaintiff for damages attributable to water seepage from the Defendants’ Premises to the Plaintiffs’ Premises” is entirely redundant. This cannot be right on the plain reading of §10 of the defence. To my mind, the effect of §10 of the defence is that the defendants, “for the purpose of saving time and costs”, will admit liability as long as the plaintiff can prove that the water seepage in Flat 2A is originated from Flat 3A.

134.Having said that, I am inclined to think that this is not an appropriate case to enter judgment under RDC Order 27, rule 3 because the defendants’ admission of liability to compensate the plaintiff, as stated in §10 of the defence, cannot be said to be clear and unambiguous in the light of the denials and non-admissions in §§7-9 of the defence.

135.I would therefore proceed to deal with the issue of whether the defendants had any knowledge of the cause of water seepage in Flat 2A and failed to take reasonable means to abate it as alleged.

F2.  Whether the defendants had knowledge of the source of water seepage and failed to take reasonable means to abate it

136.It has been said that a defendant is not liable for nuisance if he does not know that the source of nuisance originates from his property: Sachdeva and Anor v Sandhu and Anor [1989] 1 EGLR 273, 277. In Loke Yuen Jean Tak Alice (supra), §54, Marlene Ng J explained that it does not follow that the plaintiff has to establish the particular water source or route is from the flat above the affected property (e.g. which drainpipe in such flat was defective that leaked waste water by which particular route to the affected property below to emerge as water leakage) in order to satisfy the requisite “knowledge”.

137.In Sedleigh-Denfield v O’Callagan and Others [1940] AC 880, the House of Lords held that an occupier of land “continues” a nuisance if, with knowledge or presumed knowledge of its existence (e.g. a defective grating giving rise to flood damage in that case), he fails to take reasonable means to bring it to an end when he has reasonable time to do so.

138.In 張秀玲及吳炳漢 對 鄭禮莊, CACV 268 of 1998 (9 April 1999), §26, the Court of Appeal explained the requisite actual or presumed knowledge as follows:-

“漏水可能導致「滋擾」，而法律就這項目有很明確的規範。簡單地說，有以下幾種普遍情況：

(1) 若漏水是在一處地方（包括樓宇單位）中發生，招致鄰舍（包括另一單位）損失時，而事源地方的戶主（是使用該地方的人，不一定需要是業主）明知漏水根源，他便是有意圖滋擾而須負法律責任。法律責任包括賠償及受禁制令禁制。

(2) 若漏水不是事源地方戶主自己或自己應代為負責的人所招致，而他又不知道漏水已發生，他就不須對漏水所招致鄰舍的損失負責。

(3) 若漏水不是事源地方戶主自己或自己應代為負責的人所招致，當他知道漏水源於他單位內，他須在無合理延誤下作出補救。否則，他須為該項漏水所招致鄰舍的損失負上法律責任。

(4) 以上三項中的「知道」，是指兩種情況：(a) 是實質地知道，或 (b) 是在通常及合理謹慎下應可知道。故此，就算戶主實質上不知道漏水的存在，因為他不在事源地方，他也不能藉此推卸責任。他身為戶主，對自己使用的地方要負法律責任。若在通常的情況下戶主應可知道有關使用地方的情況，在法律上他就被當作知情。作為地方的戶主，他應對該地方作出合理謹慎的處理。故此，對該地方的情況而言，一切他應在合理謹慎下可知道的，法律也當他知道。

(5) 第 (2) 和第 (3) 項所述的「戶主應代為負責的人」，是指一切戶主准許進入或使用戶主地方的人，包括他的家人、朋友、僱員和入內工作的人，但不包括未獲他或上述的人准許而進入地方的人。”

139.In the present case, the defendants claim that even though they first learned about the water seepage problem in Flat 2A in April 2015, they only acquired actual or constructive notice that such water seepage originated from Flat 3A when they received a letter dated 4 June 2018 from the Joint Office regarding the bathtub of Flat 3A Master Bathroom. At all material times, they took remedial steps within a reasonable time, and therefore, even if Flat 3A is found to be the source of water seepage to Flat 2A, the defendants should not be held liable at all.

140.During cross-examination, the 1^st defendant admitted that he had learned in 2017 that despite the repair works of the communal drainage pipe performed by the Management Office in April 2016, the water seepage problem in Flat 2A still persisted. On the other hand, on the plaintiff’s own evidence, the source of water seepage had not yet been ascertained when the Joint Office conducted inspections in June to August 2017. In the premises, it appears that the defendants had not yet acquired actual knowledge, nor should they be imputed with constructive knowledge, of the source of water seepage in Flat 2A in 2017.

141.Nevertheless, the defendants must have acquired actual knowledge that the water seepage problem in Flat 2A originated from Flat 3A when they received the Joint Office’s letter dated 4 June 2018 informing them that the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom was found to be defective and resulted in water seepage.

142.During cross-examination, the 1^st defendant sought to claim for the first time that the Joint Office only suspected but did not confirm in its letter that Flat 3A was the source of water seepage in Flat 2A. Such allegation must be rejected because (1) the defendants have never produced a copy of the Joint Office’s letter to them to substantiate the allegation, and (2) the 1^st defendant accepted that the letter issued by the Joint Office to the defendants was similar to the one issued by the Joint Office to the plaintiff dated 4 June 2018, in which the Joint Office stated unequivocally that the test results revealed that the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom was found to be defective, resulting in water seepage (“測試結果顯示，上層有關單位主人浴室浴缸的地台防水設施有欠妥跡象，出現滲水情況”). It is most unlikely that the Joint Office’s letter to the defendants of the same date would suggest anything otherwise.

143.After the defendants acquired actual knowledge that Flat 3A was the source of water seepage in Flat 2A, it is evident from their own case and the undisputed evidence that they have failed to take reasonable steps to bring the water seepage problem to an end within a reasonable time.

144.First, there is no dispute that the defendants did not make any repairs to the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom, which they knew constituted a source of nuisance to Flat 2A as stated in both the Joint Office’s letter dated 4 June 2018 and the Nuisance Notice dated 20 November 2018, until after the plaintiff commenced these proceedings in July 2019.

145.The defendants now pray in aid the inspection conducted by the Management Office at Flat 3A on 13 June 2018 which they say did not reveal the source of water seepage. There is no suggestion that such staff member(s) of the Management Office professed to have any specialist knowledge in investigating the source of water seepage, nor that any scientific test was done during the inspection. The Incident Log recorded that the staff member(s) of the Management Office only carried out a visual inspection (“視察”). In these circumstances, I am of the view that there is no reasonable basis for the defendants to rely on the result of such visual inspection to contend that they did not have any duty to make repairs to the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom as per the Joint Office’s letter dated 4 June 2018.

146.Then, on 14 July 2018, a further inspection by a staff member of the Management Office at Flat 3A revealed that there was water upon opening the access panel of the bathtub of Flat 3A Master Bathroom. According to the Incident Log provided by the Management Office to the defendants by letter dated 31 July 2019, although the Management Office could not ascertain if the same was the source of water seepage, the defendants agreed to make repairs of this part first (“您們承諾會先做好此部份之維修”). In my view, the fact that the defendants replaced the bathtub drainage pipe subsequently does not relieve them from their duty to also make repairs to the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom as per the Joint Office’s letter dated 4 June 2018, because (1) these are separate and distinct causes of water seepage, and (2) water in the bathtub can pass through the defective waterproofing layer and move downwards into Flat 2A before it ever reaches the drainage pipe, so replacing the drainage pipe cannot remedy the water seepage problem once and for all.

147.However, even after the Nuisance Notice was issued by the Joint Office on 20 November 2018, the defendants still did not carry out any repair works in relation to the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom because, according to the 1^st defendant’s evidence, he believed that the water seepage mentioned in the Nuisance Notice had been sufficiently addressed by the replacement of the bathtub drainage pipe in July 2018.[21] According to the 1^st defendant’s oral evidence at trial, the defendants never engaged any professionals to carry out any investigation of the waterproofing layer in the floor slabs of the bathtub of Flat 3A Master Bathroom. In the premises, there can be no reasonable basis upon which the defendants could simply rely on the replacement of bathtub drainage pipe in ignoring and defying the requirements set out in the Nuisance Notice to repair the waterproofing layer in Flat 3A Master Bathroom.

148.Insofar as the defendants seek to rely on the health condition of the 1^st defendant’s father as the reason for not taking action to comply with the requirements of the Nuisance Notice nor allowing the plaintiff’s appointed expert to make inspection at Flat 3A, such reliance is misplaced:-

(1)  Whilst it is understandable that the 1^st defendant was concerned about his father after he had heard from his brother on 20 December 2018 that their father’s cancer was growing out of control, it does not mean that the defendants were therefore justified in sitting on the Nuisance Notice and rejecting the plaintiff’s reasonable requests for inspection in the circumstances of this case, in particular, given that the water seepage problem in Flat 2A still persisted after the defendants’ replacement of the bathtub drainage pipe in July 2018.[22]

(2)  On the defendants’ own case, they visited the 1^st defendant’s father in Canada between 27 April and 13 May 2019, viz for around 2.5 weeks. Other than these 2.5 weeks, there was plenty of time for them to remedy the water seepage problem by repairing the waterproofing layer in Flat 3A Master Bathroom and to allow the plaintiff’s expert to make inspection of Flat 3A. The 1^st defendant said in oral evidence that he was not in the mood (“冇心情”) to handle the matter and he thought a delay of 3 months was not a big deal. This, in my view is evident that he took a cavalier attitude towards the persistent water seepage problem in Flat 2A. For completeness, there is no evidence that the 2^nd defendant took any action to remedy the water seepage problem after receiving the Nuisance Notice.

149.The defendants’ letter dated 24 June 2019 to the plaintiff’s solicitors is telling that they simply ignored the requirements set out in the Nuisance Notice. What they stated in respect of the flooring of Flat 3A Kitchen, Master Bathroom and guest bathroom was that the Joint Office had conducted “colour liquid tests” over the past two years and did not make any further comment. This is factually incorrect because the Joint Office had issued the Nuisance Notice requiring them to repair the floor slabs and enclosing walls of the bathtub of Flat 3A Master Bathroom. In any event, the defendants knew or must have known that the results of the “colour liquid tests” are inconclusive because, notwithstanding the negative results of the tests done by the Joint Office and Pioneer in 2017 and early 2018, Flat 3A Master Bathroom was still found to be the source of water seepage by the Joint Office in its letter dated 4 June 2018 and in the Nuisance Notice.

150.Only after the plaintiff issued these proceedings in July 2019 did the defendants decide to carry out renovation works in Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom. Still, as admitted by the 1^st defendant in his oral evidence, he did not first liaise with the plaintiff as to the extent of the works and whether such works would be sufficient to abate the water seepage problem caused by Flat 3A. No explanation has been given by the defendants as to why no repair works were done to Flat 3A Kitchen despite the persistent water seepage problem in Flat 2A Bedroom. As for the work done in Flat 3A Master Bathroom, it is clearly insufficient to bring the water seepage problem to an end because the defendants’ own expert, Mr Chung, accepts that persistent water seepage was still found in Flat 2A Cloakroom during the joint inspections which were carried out after the renovation work had been completed in Flat 3A Master Bathroom.

151.Further, even after Mr Lau and Mr Chung conducted the joint inspections and delivered their respective expert reports in February 2020 in which both experts, among other things, agreed that there was continuous water seepage in Flat 2A Bedroom and Flat 2A Cloakroom despite the renovation works, still the defendants have taken no reasonable remedial action to abate the water seepage problem up to date.

152.For the above reasons, I find that the defendants, despite having actual knowledge that their Flat 3A was the source of such water seepage since June 2018, have not taken reasonable steps to abate the water seepage problem in Flat 2A up to date, thus failing in their duty to maintain their property (viz. Flat 3A) in good repair and condition under section 34H(1) of the BMO and Clause 42 of the DMC.

153.For the same reasons, I also find that the defendants are liable in nuisance and negligence to the plaintiff for their failure to remedy the defects in the waterproofing layers, flush water supply pipes and the hand-wash basin drainage pipe in Flat 3A, causing water seepage, and thereby damage, to Flat 2A.

G.  REMEDIES

G1.  Injunctive relief

154.The plaintiff claims a mandatory injunction that the defendants shall carry out all necessary repair works in Flat 3A to stop and prevent water leakage from Flat 3A to Flat 2A, with certificate of satisfaction to be issued by an independent authorised person, building surveyor or engineer to be jointly appointed by the parties and at the defendants’ expenses and with liberty to apply if the parties could not agree on the candidate: cf. Evergreen Hong Kong Investment Limited v The Incorporated Owners of Tregunter and Anor [2021] HKDC 1111, §277(1). The defendants argue that it is disproportionate and unjust to order them to undertake “speculative, open-ended and onerous work, which may well not end up solving the relatively minor continuing water seepage”.[23]

155.I do not agree that the water seepage problem in Flat 2A is a relatively minor one as alleged by the defendants. Both experts agree that there is continuing active water seepage in Flat 2A Bedroom and Flat 2A Cloakroom, with water dripping from the ceiling of Flat 2A Bedroom. As for Flat 2A Maid’s Bathroom, active water seepage ceased by the time of the experts’ joint inspections. Nonetheless, if no repair works are carried out to remedy the defective waterproofing layer and drainage pipe of the hand-wash basin in Flat 3A Maid’s Bathroom, it is probable that water seepage in Flat 2A Maid’s Bathroom would resurface and cause further damage to Flat 2A.

156.Nor do I agree that an injunction would require the defendants to undertake speculative, open-ended and onerous work. In the light of the court’s findings on the cause of water seepage in Flat 2A and the corresponding defects in Flat 3A, the defendants should be able to identify and carry out the necessary remedial works to be done in Flat 3A in order to abate the water seepage problem caused to Flat 2A.

157.In the circumstances of this case, I find that damages alone would not be an adequate remedy to the plaintiff, and that a mandatory injunction is necessary and warranted to rectify the water seepage problem in Flat 2A.

158.Having heard the parties on the proposed terms of the injunctive relief, I will make an order in terms of §1 of the plaintiff’s proposed order as amended: see §196 below.

G2.  Damages

159.The plaintiff claims damages as follows: (1) the costs of rectification works at $143,884; (2) the costs of substituted accommodation during repair works at $11,200; (3) the costs of general cleaning at $1,600; (4) the survey fees of HKSL at $40,000; and (5) damages for distress, discomfort and inconvenience at $100,000.

G2a.  Costs of rectification works

160.The plaintiff claims the costs of rectification works done or to be done in Flat 2A which, according to the opinion of Mr Lau, amount to $143,884 in total.

161.The defendants dispute the amount claimed by the plaintiff under this head. According to Mr Chung’s opinion, the reasonable costs of rectification works should be $53,262. He also opines that a 20% discount should be applied for depreciation.

162.As explained by HH Judge A. Cheung (as the Chief Justice then was) in Wong Ping Mui v Mak Hung On, DCCJ 2874 of 2001 (12 October 2001), §4, citing McGregor on Damages (16^th ed, 1997), p 1328,[24] the general principle is that, where the plaintiff’s goods have been damaged, the basic pecuniary loss is the diminution in their value which is normally measured by the reasonable cost of repair, and generally without making any deduction from the damages on account of the fact that after repair the goods are in better condition than they were before the tort.

163.In the present case, I am of the view that there is no reason why the court should depart from the general principle as stated above, given that the defendants have not adduced any evidence suggesting that the plaintiff is seeking to recover more than she has lost. In any event, the assessment of the plaintiff’s claims below would be made on the basis that the plaintiff will only be allowed the reasonable cost of repair. In the premises, no deduction from the damages on account of depreciation or betterment should be made.

Item A:  Demolition works

164.The plaintiff claims a total sum of $22,650 for the demolition works to be done to Flat 2A Bedroom, Flat 2A Cloakroom and the master bedroom of Flat 2A (“Flat 2A Master Bedroom”) (of which Flat 2A Cloakroom forms part). Mr Chung opines that a sum of $4,356 is reasonable for such works.

165.The experts agree that one man-day for a general worker costs $1,210, and that overheads and profit (“OH&P”) at 20% of the labour and material costs should be allowed. Their difference in opinion mainly lies with the extent to which the timber floor and skirting in Flat 2A Bedroom and Flat 2A Master Bedroom should be replaced. Whilst Mr Lau considers that the entire timber floor and skirting should be replaced, Mr Chung opines that only those parts affected by water seepage would have to be replaced.

166.On balance, in view of the coloured photos taken by the experts during the joint inspections, I would prefer Mr Chung’s opinion that the stains found on the floor of Flat 2A Bedroom and Flat 2A Master Bedroom are not so serious as to warrant the replacement of the entire floor and skirting. Although there is no dispute that black dots and mould would be developed sooner or later if timber floor and skirting is soaked with water, especially salt water, for a period of time, the plaintiff has not adduced any updated evidence such as photos to prove that this is indeed the case in Flat 2A Bedroom and Flat 2A Master Bedroom. I am therefore not minded to allow the entire sum as claimed by the plaintiff under this item.

167.Having said that, I find that Mr Chung’s estimate of 3 man-days for all demolition works is too low. I consider that it is reasonable to allow 6 man-days. Further, I note that Mr Chung’s assessment has not taken into account the 30% material costs as opined by Mr Lau. Mr Chung stated in his Report that no material costs could arise in demolition works, but he has accepted in oral evidence that protective materials would be required during demolition works and claims that he has included the costs of such materials in his assessment. Given Mr Chung’s conflicting evidence in this regard, I would prefer Mr Lau’s estimate of 30% material costs.

168.In the premises, the total amount allowed under this item would be $11,325.60 ($1,210 x 6 man-days x 1.3 x 1.2).

Item B:  Painting works

169.The plaintiff claims a total sum of $27,450 for the painting works to be done to the ceilings and walls of Flat 2A Bedroom and Flat 2A Cloakroom. Mr Chung opines that a sum of $16,616 is reasonable for such works.

170.The difference in opinion between the experts lies with the assessment method. Mr Lau adopts an all-inclusive market rate of $70 per square metre, whereas Mr Chung adopts a labour and material build-up assessment with an estimate of 6 man-days at a rate of $1,210 per man-day plus 20% OH&P and material costs at $5,000. Mr Chung explains that the rate of $1,210 is an average figure used for various types of workers and is appropriate “even if in some items of work this rate would be slightly below the skill of the worker”.[25]

171.In my view, Mr Chung’s adoption of the rate of $1,210 for the costs of a painter per man-day appears to be on the low side and does not reflect the generally higher rate charged by a painter when compared to that of a general worker due to the more sophisticated skills required of a painter. Also, Mr Chung has not applied the 20% OH&P to the material costs of $5,000. For these reasons, I do not accept Mr Chung’s assessment of this item of work.

172.Given the areas involved for the painting work are relatively large, at 38 square metres and 23 square metres respectively, I consider that Mr Lau’s assessment is reasonable and would allow the full sum of $27,450 as claimed by the plaintiff.

Item C:  Carpentry works and air-conditioners

173.The plaintiff claims a total sum of $70,511 for the carpentry works to be done to Flat 2A Bedroom, Flat 2A Cloakroom and Flat 2A Master Bedroom, as well as the new air-conditioners therein. Mr Chung opines that a sum of $17,700 is reasonable for the same. It is common ground that items C1 and C2 (viz. gypsum ceiling and aluminium ceiling light fitting in Flat 2A Bedroom), in the total sum of $6,746, should be allowed, whereas no sum should be allowed under items C3 and C4 (viz. wardrobe and bed in Flat 2A Bedroom).

174.In relation to the carpentry works, as explained above, I consider that the plaintiff’s claim for the costs to replace the entire timber floor and skirting in Flat 2A Bedroom and Flat 2A Master Bedroom should not be allowed. Therefore, I would disallow item C5 (viz. composite timber floor board in Flat 2A Bedroom). As for items C6 (viz. timber skirting in Flat 2A Bedroom) and C10 (viz. composite timber floor board in Flat 2A Cloakroom), I would allow the sums of $1,000 and $5,400 respectively as opined by Mr Chung given the narrower scope of work required.

175.Items C8 and C9 concern the wardrobe and short wardrobe in Flat 2A Cloakroom. I prefer Mr Lau’s assessment of $10,200 for the wardrobe since the unit rate adopted by him has taken into account the size and height of the wardrobe, whereas Mr Chung’s assessment based on foot run does not take into account the size of the wardrobe and it is not clear from his evidence how should the unit rate be adjusted for wardrobes of difference sizes. However, I do not agree that the short wardrobe requires replacement since the photos taken by Mr Chung do not show any significant damage to the existing short wardrobe in Flat 2A Cloakroom. I would therefore disallow item C9.

176.Turning to the air-conditioners, it is the plaintiff’s case that the old ones were beyond repair because of the water seepage problem and therefore she replaced the same by the time of the joint inspections but has not kept the receipts. Mr Lau assesses the reasonable costs for supplying and installing the 1 horsepower ceiling-mounted split-type air-conditioner in Flat 2A Bedroom at $12,732, and those for the 1.5 horsepower wall-mounted split-type air-conditioner in Flat 2A Master Bedroom at $13,600. His assessment is based on the installation of the two air-conditioners being done on different days. On the other hand, Mr Chung opines that a total sum of $18,004 should be reasonable for the supply and installation of both air-conditioners at the same time. It appears to me that Mr Lau’s assessment in this respect is on the high side, and I would prefer Mr Chung’s assessment of $18,004 as a more reasonable sum.

177.In summary, I would allow a total sum of $41,350 ($6,746 + $1,000 + $5,400 + $10,200 + $18,004) for this item.

Item D:  Miscellaneous works

178.The experts agree that (1) a sum of $1,874 should be allowed for item D1 (viz. the inspection of electrical appliances in Flat 2A Bedroom and Flat 2A Master Bedroom), (2) a sum of $3,066 should be allowed for item D3 (viz. the protection of the floor and furniture in the living and dining areas in Flat 2A), and (3) a sum of $4,000 should be allowed for item D6 (viz. the insurance premium payable for the construction works).

179.Since I am of the view that the timber floor in Flat 2A Master Bedroom does not have to be replaced, I will not allow item D2 (viz. the costs for dismantling and re-installing the bed therein).

180.The experts disagree on item D4 (viz. the costs for carting away debris during the construction period). Given my view that the scope of work to be done in Flat 2A does not include the replacement of timber floor and skirting in Flat 2A Bedroom and Flat 2A Master Bedroom, I would prefer Mr Chung’s assessment of $2,050 for the costs for carting away debris.

181.As for item D5 (viz. the costs for cleaning works to be done in Flat 2A), on the basis that there would be no replacement of timber floor and skirting in Flat 2A Bedroom and Flat 2A Master Bedroom, Mr Lau assesses the cleaning costs at $4,200 whereas Mr Chung assesses the same at $3,600. I consider the sum of $3,600 is reasonable and would allow the same.

182.In summary, I would allow a total sum of $14,590 ($1,874 + $3,066 + $4,000 + $2,050 + $3,600) for this item.

Summary

183.In the premises, I would allow the plaintiff’s costs of repair at the total sum of $94,715.60 ($11,325.60 + $27,450 + $41,350 + $14,590).

G2b.  Costs of substituted accommodation

184.According to the plaintiff’s case, because of the rectification works to be carried out in Flat 2A, her family members would require substituted accommodation for 14 days at a daily rate of $800. The defendants do not dispute the daily rate of $800, but contend that 8 days should be sufficient.

185.Adopting a broadbrush approach, I consider that the rectification works should probably take 10 working days. On such basis, and taking into account the intervening Sunday, I consider that the reasonable period during which the plaintiff’s family members would require substituted accommodation should be 11 days.

186.In the circumstances, I would allow the rounded off sum of $8,800 ($800 x 11 days) under this head of claim.

G2c.  Costs of general cleaning

187.The plaintiff claims a sum of $1,600 ($200 x 8 hours) for general cleaning in Flat 2A, whereas the defendants contend that it should be disallowed because it is a duplication with item D5: see §181 above.

188.In my view, since cleaning costs have been provided in item D5 above, I am not minded to allow the plaintiff’s claim under this item.

G2d.  Survey fees

189.The plaintiff claims the survey fees charged by HKSL in respect of the preparation of the HKSL Report as damages. Given that the HKSL Report was issued around two months before the commencement of these proceedings and was provided to the defendants as an enclosure to the plaintiff’s pre-action letter dated 18 June 2019, I am inclined to think that these fees should form part of the plaintiff’s legal costs incurred in these proceedings: Yim Wai Ling and Anor v Yuen Chik Wah and Anor, DCCJ 663 of 2013 (12 August 2016), §95. I would therefore not allow the same as damages.

G2e.  Damages for distress, discomfort and inconvenience

190.The plaintiff claims a sum of $100,000 under this head, whereas the defendants contend that general damages should be in the region of $45,000 (on the basis that the defendants first acquired knowledge that Flat 3A was the cause of water seepage on 4 June 2018) or $60,000 (on the basis that the water seepage problem in Flat 2A started in early 2015).

191.I note that the cases cited by Mr Chau in his closing submissions[26] make it clear that general damages should be assessed for the entire period during which the plaintiff’s property suffered from water seepage, and are not limited to the time when the defendants acquired knowledge of the cause of water seepage.

192.I have considered all of the relevant authorities cited by Mr Yan and Mr Chau, including Chan Albert Koon Keung and Others v Yee Yun Tung [2020] HKDC 1201, in which the court awarded a sum of $80,000 as general damages for water seepage which lasted for 5 years and occurred at the entrance, kitchen, guest bedroom, dining room and living room of the plaintiffs’ property. To my mind, the water seepage problem suffered by the plaintiff in the present case is more serious than that in Chan Albert Koon Keung (supra) in that the present water seepage problem has caused substantial damage to different parts of Flat 2A for a longer period of 8.5 years.

193.In all the circumstances, in view of the duration and scope of water seepage in Flat 2A, and having regard to the relevant authorities cited by counsel, I consider that a reasonable sum to be awarded under this head is $100,000.

G2f.  Summary

194.In summary, the plaintiff is entitled to general damages for distress, discomfort and inconvenience in the sum of $100,000, and special damages for costs of rectification works and substituted accommodation in the total sum of $103,515.60 ($94,715.60 + $8,800).

H.  CONCLUSIONS AND ORDERS

195.For the above reasons, I find that the water seepage problem in Flat 2A Bedroom, Flat 2A Cloakroom and Flat 2A Maid’s Bathroom was and is caused by the defects in Flat 3A Kitchen, Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom for which the defendants are liable.

196.There shall be an order that the defendants do carry out all necessary repair works to rectify the defects in (1) the concealed flush water supply pipes in Flat 3A, (2) the waterproofing layers in Flat 3A Kitchen, Flat 3A Master Bathroom and Flat 3A Maid’s Bathroom, and (3) the drainage pipe of the hand-wash basin of Flat 3A Maid’s Bathroom, at their own costs and expenses within 70 days from the date of this judgment for the purpose of stopping and preventing water leakage from Flat 3A to Flat 2A, with certificate of satisfaction to be issued by an independent authorised person, building surveyor or engineer to be jointly appointed by the parties and at the defendants’ expenses. I grant liberty to apply if the parties could not agree on the candidate to be appointed.

197.I allow the plaintiff’s claims for general damages for distress, discomfort and inconvenience in the sum of $100,000, and special damages for costs of rectification works and substituted accommodation in the total sum of $103,515.60.

198.I make an order nisi that the defendants shall pay interest on:-

(1)  general damages at 2% per annum from the date of service of the writ to the date of judgment;

(2)  special damages for the supply and installation of the air-conditioners (see §176 above) and the substituted accommodation (see §186 above) at half of the judgment rate from the date of service of the writ to the date of judgment; and

(3)  the aforesaid damages at the judgment rate hereafter until full payment.

199.On the issue of costs, it is fair to say that the plaintiff is the successful party and should be allowed the costs of her claim. Nonetheless, the defendants claim that they should in any event be entitled to the costs of and occasioned by the second adjournment of the trial[27] on 20 September 2022 when Mr Yan was subject to a quarantine order[28] and therefore could not attend trial, citing Chan Fuk Tai and Others v Chan Wai Ming [2020] HKCFI 2352. Mr Yan submits that he was prevented by the law from attending the trial due to the quarantine order, which is distinguishable from those situations where adjournment was made on the ground of the sudden illness of counsel or a witness.

200.I can see some force in Mr Yan’s argument that he was essentially prevented by a lawful quarantine order issued by a health officer under the Prevention and Control of Disease Regulation (Cap 599A) from attending trial on 20 September 2022. On the other hand, the defendants did not ask for an adjournment and it seems unsatisfactory that they shall have to bear the costs of the adjournment. I appreciate that it was an unfortunate incident which was very much a vicissitude of life during the COVID-19 pandemic, for which no one should be blamed. Having considered all the circumstances of this case, I think it is fair and just to order the plaintiff to pay the defendants’ costs of and occasioned by the adjournment, which shall be limited to one refresher of Mr Chau and the time costs of the defendants’ solicitors for attending the hearing on 20 September 2022.

201.I therefore make an order nisi that:-

(1)  the plaintiff do pay the defendants’ costs of and occasioned by the second adjournment of trial on 20 September 2022, which shall be limited to one refresher of Mr Chau and the time costs of the defendants’ solicitors for attending the hearing on 20 September 2022, to be taxed if not agreed; and

(2)  save as provided for in sub-paragraph (1) above, the defendants do pay the plaintiff’s costs of the action, with certificate for counsel, to be taxed if not agreed.

Mr Yan Kwok Wing, instructed by CL & Co Solicitors, for the plaintiff

Mr Ian Chau, instructed by Wong, Hui & Co, for the 1^st and 2^nd defendants