sample joint expert witness report - … · 5.13 we noted severe black spot mould colonization to...

Chartered Building Consultants & Chartered Building Engineers

Building Surveys, Project and Asset Management, Design & Specification, Works/Contract Management & Asbestos Management.

Specialist in independent damp investigations & building defect analysis www.maloneassociatesltd.co.uk

Joe Malone BSc(Hons), P402 Cert. MCIOB, MCABE Principal: Malone Associates Ltd

Landline: 0800 0437732 Mobile: 07447 030254 Email: [email protected] 1 Bracken Close, Nottingham, NG4 3QJ

Single Joint Expert Witness Report to Determine the cause and severity of Dampness

Block 1-15, High Street, Brierley Hill, DY5 3AA

Date of inspection: 13th January 2015 at 10.30am

Inspection carried out by Joe Malone BSc (Hons) MCIOB, MCABE

Prepared by: Malone Associates Ltd

Prepared for: Dudley County Court 7 Hagley Road Stourbridge West Midlands, DY8 1QL

Reference: Single Joint Expert Witness Report 1-15 High Street, Brierly Hill

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1.0 INTRODUCTION

1.1 Malone Associates Ltd were jointly instructed by Mr & Mrs Mehmi and Lex Allan Group to provide a joint expert witness report relating to the cause and severity of dampness within a number of flats within blocks 1-15 High Street, Brierley Hill.

1.2 This report is addressed to the Court as per the requirements of part 35 of the Civil

Procedural Rules.

1.3 Joint Instructing Parties

Mr R K & Mrs S R Mehmi (Leaseholder)

34 Westbourne Road

Wednesbury

West Midlands, WS10 8BJ

Vantage Property Investments Ltd (Freeholder)

C/o Lex Allan Group

The Auction House

87/88 St Johns Road

Stourbridge, DY8 1EH

1.4 General Principle

It is not within any surveyors remit to interpret leases – only to understand a lawyer’s interpretation of the lease. Our expertise is in the identification of building defects and disrepair. We generally make no attempt at interpretation of the lease documents beyond understanding repair obligations under the terms of the Head lease.

2.0 DESCRIPTION

Block 1-15 High Street, Brierley Hill is a typical characterless 1960’s development seen in many shopping precincts. The block is of concrete frame construction with rendered brick infill panels. Floor and roof construction is also of reinforced concrete. The ground floor premises to the front elevation are occupied by retailers who ply their trade on the High Street, whilst the floors above form individual flats for residential use. The front street elevation of the building occupies a lower level than the rear elevation so ground floor flats at Bell Court actually occupy first floor level on the front elevation. Interestingly, these first floor flats jetty out above the walkway to the shops at ground floor level. The significance of this will be discussed in the main body of the report.

3.0 LEGAL BACKGROUND


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A dispute exists between both parties named in section 1.3 of this report as to the state of repair and the general cause of dampness within the residential flats at 1-15 High Street. A previous experts report has ruled out penetrating damp through the roof deck and we concur with those findings.

4.0 EXTERNAL OBSERVATIONS 4.1 We noted that the external structure is generally in an extremely dilapidated condition.

The concrete frame is heavily spalled, as are the rendered infill panels. See figures 1,2,3, 4 & 5.

Figure 1. Spalling concrete and failed render on window mullions

Figure 2. Severe concrete carbonation to head of window


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Figure 3. Failure on concrete lintel due to carbonation

Figure 4. All external failures provide a pathway for penetrating damp.


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Figure 5. More failures of external building envelope

4.11 We noted areas of the building that are generally extremely poorly insulated unless

upgraded to modern standards for thermal values. In particular, the concrete frame, roof and floors of the undercroft are all poorly insulated and can provide issues with excessive heat loss and direct cold bridging. See figure 5.

Figure 6. Highlighting why the building has poor standards of thermal comfort.


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4.12 We noted complete failure of the windowsill flashing detail and noted that this will provide a pathway for water ingress into the building. See figure 6.

Figure 7. Failure of windowsill flashing detail and render for top floor flat.

4.13 We noted a number of external defects to the front (North) elevation of the flats at Bell

Court:

1. A UPVc door is smashed at the door base of flat number 7. 2. Open brickwork where a services utility cupboard had been removed. 3. A displaced and loose doorframe to flat number 2 is causing penetrating damp into

the flat. 4. Severe penetrating damp from leaking overflow at first floor balcony level. 5. All external utility cupboards left open are a potential source for penetrating damp.

See figure 8 & 9.


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Figure 8. Defects and problems noted on North Elevation of Bell Court.

Figure 9. Potential problems on North elevation


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5.0 INTERNAL OBSERVATIONS Flat 7 5.11 Condensation Risk Readings 5.12 It was necessary to assess for condensation risk and to that end the following readings

were recorded. Relative humidity = 68%, Dew point temperature = 10.6oC, Ambient temperature = 16.6OC

Wall temperatures were recorded at 8OC and ceiling temperatures were recorded at 6oC,

the ceiling was 4.6oC below dew point temperature. This proves that on the day of inspection the property was suffering from a serious active condensation damp problem.

5.13 We noted severe black spot mould colonization to the walls and ceiling of the lounge and

bedroom. See figure 10 & 11

Figure 10. Decorative spoiling and mould colonization to lounge

5.14 We carried out thermal imaging in the flat and noted areas of severe cold bridging or

dampness to the walls and ceiling in the lounge. Areas shown in blue within the thermal signature can be cold bridging or damp and a follow up survey with a moisture meter will confirm or rule out dampness. See figures 10.


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Figure 11. Blue areas show severe cold bridging or damp to walls and ceiling of lounge

5.15 We noted severe cold bridging to the internal windowsills. See figure 11.

Figure 12. Cold bridging to windowsill


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5.16 We noted severe damp or cold bridging to the southwest corner of the bedroom and

indeed, this is what we expected to see after noting the large section of external concrete framework seen in figure 6. See figure 12.

Figure 13. Severe cold bridging and/or damp to the corner of bedroom wall

5.17 We took surface moisture readings from the walls and ceilings of the lounge and

bedroom using a Protimeter Surveymaster in pin mode and recorded the highest reading of 24.9 R/R (RR = Relative Reading) on the south facing wall of the lounge and <20 R/R on the walls and ceiling of the bedroom. Readings of 20 R/R or below at surface are not considered as requiring further investigation but readings above 20 R/R mean that the investigation must move forward with testing for moisture at depth in the masonry. To that end we drilled the south wall at the head of the window to test for moisture at depth using deep wall probes and recorded a reading of only 20 R/R. See figure 14.


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Figure 14. Use of deep wall probes rules out penetrating damp.

Bathroom

5.18 We noted extreme mould colonization to the bathroom. See figure 13.

Figure 15. Severe mould colonization and decorative spoiling to bathroom ceiling & walls


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We also noted that the bathroom extractor fan was non-functional and that the rendered ceiling was severely cracked. See figure 16.

Figure 16. Severely cracked render to ceiling.

Heating 5.19 We noted that the flat was extremely poorly heated; there was no heating to the lounge,

there was a wall heater to the bathroom and Stiebel storage heaters to the bedroom and hall. The heating was inadequate and not fully controllable.

Hall/Stairwell 5.20 We noted severe black spot mould colonization to the hall and stairwell. See figure 17.

Figure 17. Mould is so bad that you can write your name in it.


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Flat 5 5.21 We noted decorative spoiling due to mould colonization and paper peeling from the

lounge ceiling. See figure 18.

Figure 18. Paper peeling from ceiling and mould above window head.

5.22 We took surface moisture readings from the walls and ceilings of the lounge and bedroom using a Protimeter Surveymaster in pin mode and recorded the highest reading of 17.5 R/R (RR = Relative Reading) on the south facing wall of the lounge

Figure 19. Low surface readings for damp.

5.23 We noted severe cold bridging above the doors and windows when checked with thermal imaging. See figure 20 & 21.


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Figure 20. Cold bridging to bulkhead above door.

Figure 21. Cold bridging above lounge window bulkhead and ceiling

5.24 We noted that the wall below the lounge window was 30mm thicker than the wall above the lounge window and had clearly been over-boarded to improve insulative values.

5.25 We noted that UPVc double glazed installation was installed to the property.


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5.26. We noted that wall mounted electric heaters were installed and that the heating system could not be described as fully controllable.

5.27 Dew point temperature was recorded at 10.6OC. Wall temperatures were recorded at 9OC

and ceiling temperatures were recorded at 7oC, the ceiling was 3.6oC below dew point temperature. This proves that on the day of inspection the property was suffering from a serious active condensation damp problem.

5.28 The property was fitted with functional extractor fans to the kitchen and bathroom. Flat 9. Condensation Risk Readings 5.29 It was necessary to re-assess for condensation risk and to that end the following readings

were recorded. Relative humidity = 57.7%, Dew point temperature = 9.7oC, Ambient temperature = 17.7OC

Wall and ceiling temperatures were recorded at 5OC, 4.7oC below dew point temperature.

This proves that on the day of inspection the property was suffering from a serious active condensation damp problem.

5.30 We took surface moisture readings from the walls and ceilings of the lounge and bedroom

using a Protimeter Surveymaster in pin mode and recorded the highest reading of 17.3 R/R (RR = Relative Reading) on the south facing wall of the lounge

5.31 We were surprised to find that there was no heating installed to the lounge, kitchen or bathroom so the property could not be adequately heated.

5.32 We noted that extractor fans were fitted to the kitchen and bathroom but neither fan was

functional. 5.33 We carried out thermal imaging in the flat and again noted severe cold bridging to the

walls and ceiling. See figure 22.

Figure 22. Cold bridging to the wall and ceiling of the bathroom.


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Flat 8 Condensation Risk Readings 5.34 It was necessary to re-assess for condensation risk and to that end the following readings

were recorded. Relative humidity = 60%, Dew point temperature = 9.5oC, Ambient temperature = 16.OC

Wall and ceiling temperatures were recorded at 2OC, 7.5oC below dew point temperature.

This proves that on the day of inspection the property was suffering from a serious active condensation damp problem.

5.35 We noted that the property had wall mounted electric heaters installed and that the

heating could not be described as fully controllable. 5.36 We noted severe black spot mould and decorative spoiling to all rooms of the property.

See figure 23.

Figure 23. Mould to walls and ceiling

5.37 We noted severe damp staining to the head of the kitchen window and water dripping off the kitchen ceiling. The resident stated that he had had this problem for two years and not reported it. See figure 24.

Using the Protimeter Surveymaster in pin mode we obtained extremely high surface readings for damp of over 90 R/R. We next tested the wall and ceiling for moisture at depth using deep wall probes and obtained readings of over 40 R/R See figure 25.

The high deep wall probe readings meant that the investigation must move forward for testing with calcium carbide. The use of calcium carbide established moisture profiles and actual moisture content of the masonry.


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Figure 24. Severe damp staining and water dripping from ceiling

Figure 25. High readings for moisture at depth using deep wall probes

We sampled the wall in two areas at high level and obtained a reading of 2% TMC (Total moisture content) near the ceiling line. See figure 26.


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Figure 26. Moisture content and profile obtained near ceiling line.

5.38 We noted that the kitchen and bathroom have an extractor fan installed but that the

kitchen extractor is non-functional. 5.39 Thermal imaging again showed that the property was extremely poorly insulated.

Flat 2

5.40 We re-assessed for condensation risk and to that end the following readings were

recorded. Relative humidity = 73%, Dew point temperature = 11.5oC, Ambient temperature = 16.4OC

Wall and ceiling temperatures were recorded at 7OC, 4.5oC below dew point temperature. This proves that on the day of inspection the property was suffering from a serious active condensation damp problem.

5.41 Thermal imaging revealed severe cold bridging to the external walls. See figure 27 & 28. 5.42 We noted that there was no extractor fan installed to the kitchen or bathroom 5.43 We recorded damp readings from the walls using a Surveymaster in pin mode and

recorded readings below 20 R/R. The resident complained that there was a severe damp patch behind his bed on the front wall of the property but we could not access this area for inspection.


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Figure 27. Severe cold bridging to the wall above the lounge window

Figure 28. Mould colonization caused by cold surface condensation.

5.44 We noted that the flat was extremely poorly heated; there was a wall heater in the lounge but no heating in the kitchen. The residents appeared to be using freestanding electrical


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heaters to supplement the property heating. The heating system could not be described as fully controllable.

5.45 We noted that the UPVc entrance doorframe was insecure and misaligned. As a result the doorframe is letting water and drafts into the property. The door appears to have been subject to a forced entry at some point.

6.0 CONCLUSIONS

6.1 The external envelope of the building, in particular the front elevation above the shops, is in extremely poor condition and we note this as our first point because we think that the condition of the concrete and external render to the front elevation is in such poor condition that it poses a risk to the general public from falling debris. The concrete frame of the building is suffering from severe concrete carbonation that has reached the underlying reinforcement bar causing it to rust. Rusting is an expansive reaction and as the rebar rusts it expands and blows off the concrete covering. Moreover, the render appears to be falling off in lumps and both these defects are allowing rainwater penetration into the building and preventing adequate sealing of the UPVc window frames in some areas.

6.11 All flats are suffering from severe and chronic condensation damp and widespread black

mould colonization and we would go so far as to say that these flats are not currently fit for habitation. We have no doubt that if a local environmental health officer was called to inspect these flats then the likely outcome of that visit would be that a section 20 prohibition notice would be served under the Housing Act 2004. This would define category 1 hazards under the Housing Health and Safety Rating System relating to damp and mould growth.

There is no magic bullet for dealing with condensation damp. Some of the moisture contributing to high internal relative humidity is undoubtedly caused by occupancy issues and some moisture is currently being drawn from the damp plasterwork. There are four factors that should be considered in the effective management of condensation damp:

1. Building Fabric: Is it well insulated and dry? 2. Ventilation: Have you provided effective mechanical ventilation? 3. Heating: Is there a fully controllable heating system in the property? 4. Occupancy: Is excessive moisture being generated internally by residents due to

household activities such as drying washing indoors etc?

It is clear that the primary problem with these flats is the poor levels of thermal insulation and direct cold bridging from the concrete frame and infill cladding panels. This is further compounded by extremely poor heating and lack of functional or efficient mechanical ventilation. Indeed, one flat had no heating installed whatsoever whilst some others were only partially heated. It is extremely important to keep properties heated to ensure that the building fabric stays above dew point temperature. Dew point temperature is the temperature at which condensation will form on surfaces. It is also important to ensure that ventilation is managed by judicious use of mechanical extractor fans rather than by opening windows and doors. Controlled ventilation is good, uncontrolled ventilation is bad. We have generally found that landlords like to blame condensation damp on ‘occupancy’ issues in the belief that this absolves them of any responsibility for the problem and with this in mind it is important to point out that there is no test to determine whether occupancy issues are the cause of the condensation dampness. You can only prove an occupancy related issue by the scientific examination and exclusion of all other potential


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factors. If you can prove that the building is dry and well insulated, that effective mechanical ventilation is installed and that an effective and fully controllable heating system is installed then you can logically conclude that occupancy issues are to blame. It is clear that these flats fail on all three counts, therefore occupancy related issues can not be blamed for the condensation damp until the buildings technical problems have been resolved. We were not commissioned to check the indoor air quality, however, given the high levels of mould colonization we think we can draw a reasonable conclusion that indoor air quality is probably poor due to high levels of mould spores in the air. This can be a significant issue for those sections of the population with a compromised immune system, such as asthmatics.

6.12 We examined a previous report commissioned into the state of the flat roof deck and

concur entirely with the findings of that report. There was no evidence of direct water ingress from the flat roofing system. However, the concrete roofing slab is not insulated and the ceilings are suffering quite severely from cold surface condensation, perhaps giving the impression that the roof is leaking when in fact there is no evidence of this.

6.13 We noted that a number of flats had internal lounge walls on the front elevation that had

been over-boarded with another layer of plasterboard. This is either to improve the thermal value of the walls in question or to hide penetrating damp on the front elevation of the block. Whilst this has undoubtedly improved the cold surface condensation to these limited areas we would question whether this boarding is hiding any penetrating damp, given our observations of the defects illustrated in figures 1,2,3,4,5 & 7.

6.14 There is some evidence of a minor penetrating damp problem to the wall above the head

of the kitchen window in flat number 9. The moisture profile seen in figure 26 rules out water ingress from the roof or the head of the wall but rather points towards penetrating damp at a slightly lower level. The moisture content of the masonry is moderately high at 3.1% and is likely to be contributing towards further reducing the thermal value of the wall and exacerbating the problem with cold surface condensation in this area. We are not entirely sure where the water is tracking into the kitchen on this elevation but have illustrated two possibilities in figure 29.


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Figure 29. Possible causes of penetrating damp to kitchen of flat 9.

6.15 There is also a penetrating damp problem to the doorframe of flat number two. Our view is that the door has been subject to a forced entry at some point and has not been adequately repaired or sealed in the aftermath. Additionally, the door to flat number 7 is smashed and this will be a cause of direct water ingress into the building.

6.16 We have established that the external walls and roof are poorly insulated but you should

also note the undercroft of the building seen in figure 6. This undercroft ceiling also forms the floor of the flats above and is often a source of poor insulation and high heat loss that does not get addressed.

6.17 Leaking overflow pipes are saturating the brickwork on the rear elevation of the block and

missing or damaged utility cupboards are also a source of potential water ingress into the building fabric.

7.0 RECOMMENDATIONS 7.1 The external envelope of the building requires substantial repair to prevent any ongoing

risk to the general public from falling debris. Concrete repairs and anti carbonation coatings are required to the concrete frame and the external render to the front elevation requires hacking off and renewal. Given the problems with cold surface condensation caused by poor insulation it is fair to say that this building is technically obsolescent in that it falls well short of current standards of thermal comfort. Given the works required to the external envelope it may be prudent to consider the installation of External Wall Insulation (EWI) to improve the thermal value of the building envelope. This would resolve the problem of cold surface condensation to the walls, whilst the roof or top floor ceilings could also be insulated to resolve the issue of cold bridging through the concrete roof deck.

7.11 If EWI is not installed then the individual flats should be treated to internal wall insulation

(IWI). This will involve lining all internal perimeter walls and ceilings with a layer of insulated plasterboard.


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7.12 The undercroft ceiling seen in figure 6 should be over-boarded with a layer of Kooltherm K18 insulated plasterboard, this has a class ‘O’ fire rating to prevent fire spread.

7.13 The fans to individual flats are ineffective or non-functional. Our experience tells us that

fans need to be silent in operation or they become too obtrusive and residents turn them off. Two extractors are simply not required in flats of this size and in fact if two are running consecutively on the same floor then they can pull against one another and cancel out the full effect of ventilation. Rather we would recommend that a Vectaire MF250C be installed to the bathroom and wired to run continuously with the boost speed wired to the bathroom lighting circuit. These are silent running fans that in no way bother the residents during 24-hour operation. The kitchen extractor fan should be removed and the wall should be made good. An opportunity should also be taken to install external anti blast cowls in place of the existing external wall vents.

7.14 All properties require that a fully controllable heating system be installed. Fully controllable

means that the heating system has been adequately sized after carrying out heat loss calculations on the building envelope and the resident will have the ability to set room temperatures in every room. Ideally, if a local gas supply is available then we would recommend installing an ‘A’ rated boiler and gas central heating to every property. If electric panel heaters are installed to every room then they should have a temperature control switch that allows the residents to control individual room temperatures and ideally a time clock on individual heaters. See figure 30.

Figure 30. Electric panel heater with time clock and thermostatic control.

7.15 Individual flats require a substantial clean with a proprietary fungicidal spray to deal with the widespread mould colonization and to improve indoor air-quality. We still hold a view that residents can not be absolved of responsibility to try and keep on top of mould outbreaks irrespective of what is causing the problem. It seems reasonable that they should try to keep levels of mould colonization down and generally look after their flats as would any reasonable minded tenant. However, standards of cleanliness were generally very poor in all the flats inspected and whilst we have been clear on the technical problems that are responsible for the widespread mould colonization, we have attended many more properties with similar technical problems where residents have kept on top of mould colonization through a reasonable cleaning protocol.


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7.16 External utility cupboards require renewal or repair. 7.17 Leaking external overflow pipes should be fixed. 7.18 The damaged UPVc doors and frame require renewal to flat number 2 and flat number 7. 10.0 STATEMENT OF TRUTH 10.1 I confirm that insofar as the facts stated in my report are within my own knowledge I have

made clear which they are and I believe them to be true, and that the opinions I have expressed represent my true and complete professional opinion.

Joe Malone BSc(Hons). P402 Cert. MCIOB MCABE

Director, Malone Associates Ltd

22nd January 2014

sample joint expert witness report - … · 5.13 we noted severe black spot mould colonization to...

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