Damp investigation in social housing

DAMP & MOULD INVESTIGATION IN SOCIAL HOUSING

Mike Glanfield EPSILON CONSULTANTS (IOM) LIMITED

UPPER QUEENS PIER ROAD HOUSING STUDY Report ref: ECL 1240 Dated: 02 APRIL 2014

Page |1

02 April 2014

AUTHOR MICHAEL GLANFIELD MIET MEI ACIBSE MSLL Epsilon Consultants (IOM) Limited Registered address: 7 Heather lane Abbeyfields Douglas Isle of Man IM2 7EF Tel: Mobile: Email: Web:

01624 677278 07624 346826 info@epsiloniom.com www.epsiloniom.com

Client: Ramsey Town Commissioners Townhall Ramsey Isle of Man IM8 1RT

Page |2

02 April 2014

CONTENTS 1.

INTRODUCTION

2.

EXECUTIVE SUMMARY

3.

CLIENT BRIEF

4.

INVESTIGATION

5.

DISCUSSION & ANALYSIS

6.

SOLUTIONS

7.

APPENDICIES 7.1 7.2 7.3 7.4 7.5 7.6 7.7

Page |3

AIR TIGHTNESS TEST RESULTS HEAT LOSS CALCULATION RESULTS “DAMP & MOULD IN HOMES” (SCOTTISH EXECUTIVE) “CONDENSATION IN HOMES” (NHBC) CASE STUDY – CARTREFI CONWY HOUSING ASSOCIATION SUPPLIERS DETAILS & QUOTATION– ENVIROVENT LIMITED SUPPLIERS DETAILS & QUOTATION– GRAMMER-SOLAR GmbH

02 April 2014

1. INTRODUCTION Epsilon Consultants (IOM) ltd were appointed by Ramsey Town Commissioners to investigate and report on the condensation, damp and mould problems having been identified in a number of social housing units.

2. EXECUTIVE SUMMARY The site investigation revealed that problems of black mould exists in both properties but in different degrees of severity. For example the mould in No.49 Upper Queens Pier Road appeared to be restricted to part of the wall above the window in the upstairs rear bedroom.

The mould problems in No.21 Upper Queens Pier Road, however, were more extensive and may be explained by the dwelling being situated lower down and in a more sheltered location.

The results of the air tightness tests show that the properties meet the latest Isle of Man requirements for maximum permeability and therefore help to keep the properties draft free and energy efficient. However, as discussed below air tight homes can lead to problems of high humidity if natural air leakage or ventilation is reduced.

Addressing the mould problems across the property portfolio largely depends upon whether the client wishes to implement a bespoke solution for each property or to apply a ‘one fit’ solution ‘across the board’ regardless of how severe the problem is in individual dwellings.

For example, the mould observed at No.49 Upper Queens Pier Road may be able to be controlled to within acceptable levels by relatively simple measures such as heating the rear bedroom for say 1 hour every day and cracking open the bedroom window.

The consequence of attempting a programme of ‘occupier’ implemented control measures of course is one of administration i.e. the education and training of occupiers followed by ongoing monitoring by the landlord.

An alternative approach carried out by Cartrefi Conwy Housing Association is where an Envirovent ltd ‘Positive Input Ventilation’ unit was installed into each of its 3,800 homes as part of a major home improvement programme (see appendices).

It should be noted that the landlord would still incur costs for ongoing equipment maintenance i.e. replacing air filters every 12 months and attending to breakdowns but also the issue of who pays for the running costs may be worthy of consideration.

3. CLIENT BRIEF A programme of loft and cavity insulation was carried out in 2007 throughout the majority of the tenanted properties in the housing portfolio.

Further work involving installation of new windows and doors, rainwater goods, new central heating systems and other improvements have also been widely carried out since 2007 with the aim of improving thermal performance and saving money on energy bills.

Page |4

02 April 2014

The perception is that such work has arguably created more ‘sealed’ buildings and may be resulting in increasing levels of complaints relating to condensation and internal dampness now being detected.

The following are descriptions of two properties built in different times that exhibit internal damp & condensation problems in varying degrees. These properties form the basis of the current investigation work. 

49 Upper Queen’s Pier Road, Ramsey – 2 Bedroom house; constructed 1936 of traditional cavity construction, rendered externally – smooth render except for above a cement band at first floor on the front elevation, above which is a dashed finished.

The property has had the following works carried out: a. Cavity and loft insulation: 2007 b. New external doors: 2009 c. Gas Central Heating: 2009 d. New Kitchens: 2011 e. Fascias, gutters and rain water goods: 2011



21 Upper Queen’s Pier Road, Ramsey – 3 Bedroom House; constructed 1955 of traditional cavity construction, rendered externally – rough cast render except for smooth banding around window openings.

The property has had the following works carried out: f.

Cavity and loft insulation: 2007

g.

New external doors: 2009

h. Gas Central Heating: 2009 i.

New Kitchens: 2011

j.

Fascias, gutters and rain water goods: 2011

4. INVESTIGATION The investigation into the damp and mould problems at both properties comprised of carrying out detailed visual inspections and also undertaking various testing works and procedures:

Page |5

02 April 2014

4.1 VISUAL INSPECTION (NO 21 UPPER QUEENS PIER ROAD) EXTERNAL IMAGES

DAMP AND MOULD IMAGES

Plates 4.1.1

Page |6

02 April 2014

THERMAL CAMERA IMAGES

Plates 4.1.2

BLOCKED VENTILATORS

Plates 4.1.3

Page |7

02 April 2014

4.2 VISUAL INSPECTION (NO 49 UPPER QUEENS PIER ROAD) EXTERNAL AND DAMP & MOULD IMAGES

Plates 4.1.4

THERMAL CAMERA IMAGES

Plates 4.1.5

4.3 AIR TIGHTNESS TESTING An air tightness test was carried out in accordance with the test procedure laid down in EN 13829. This involved temporarily sealing up the property and depressurising the house by a blower door fan set into one of the external doors.

Page |8

02 April 2014

The results of the air tightness test were compared with the maximum air permeability value laid down in Approved Document ‘L’ of the Isle of Man Building Regulations 2006.

The full test results are included in the report appendices and a summary is shown in table 4.3.1 AIR TIGHTNESS TEST RESULTS PROPERTY TEST RESULT 21 UPPER QUEENS PIER ROAD 8.06 M3/HR/M2 49 UPPER QUEENS PIER ROAD 5.22 M3/HR/M2

MAXIMUM VALUE 10M3/HR/M2 10M3/HR/M2

Table 4.3.1

4.4 HEAT LOSS CALCULATIONS Heat loss calculations have been carried out based upon property dimensions taken at the time of the visual inspections and the minimum ‘U’ values that were current in the building codes at the time the properties were built.

The full heat loss calculations are included in the report appendices and a summary is shown in table 4.4.1 below. The results may be compared with the actual installed boiler capacity for each property.

PROPERTY 21 UPPER QUEENS PIER ROAD 49 UPPER QUEENS PIER ROAD

HEAT LOSS CALCULATIONS RESULT 17.3 KW 19.6KW

BOILER RATING 24.0 KW 28.0 KW

Table 4.4.1

5. DISCUSSION & ANALYSIS Condensation damp or ‘black mould’ was clearly visible in both properties. However the visual and thermal camera inspection revealed that the mould problems in No.21 Upper Queens Pier Road were more extensive (see plates 4.1.1 above).

The observations may be explained by the dwelling being situated lower down and in a more sheltered location.

It was also noted that 3 No. air ventilators were blocked with dried paint thus rendering the vents inoperative (see plate 4.1.2 above).

The evidence of ‘black mould’ in No. 49 Upper Queens Pier Road appeared to be restricted to the area of wall above the double window in the rear bedroom on the upper floor (see plates 4.1.3 above).

The results of the air tightness tests carried out on both properties reveal that the permeability values fall within the requirements of Approved Document ‘L’ of the Isle of Man Building Regulations.

Researching the subject of condensation and black mould has revealed extensive written guidance and information. Copies of some of the publicly available literature have been included in the appendices to this report.

Page |9

02 April 2014

The present imperative to reduce space heating bills and carbon emissions by implementing energy saving measures such as replacing old doors and windows and providing additional insulation has increased the air tightness of dwellings (see table 4.3.1 above).

As a consequence these measures have reduced the natural ventilation of dwellings which in turn leads to increased humidity levels caused by normal respiration of the occupants together with carrying out household activities such as washing, ironing, cooking and bathing.

Increased humidity levels inside the dwelling can then give rise to condensation and black mould growth especially if the heating system is only intermittently switched on and in rooms where the humid air is in direct contact with a colder surface such as windows.

The following video produced by Envirovent limited with support from the University of Nottingham provides a graphic explanation of the causes of condensation/mould growth in buildings with inadequate natural ventilation:

YouTube link: http://youtu.be/u1gRG0DY7I 1

The accompanying literature on the subject (see appendices) highlights the problems of condensation and/or black mould growth in dwellings that can also give rise to deleterious health effects to the occupants such as:   

P a g e | 10

Increased dust mite populations Problems to asthma sufferers Increased incidents of respiratory illnesses

02 April 2014

6. SOLUTIONS Practical measures to control humidity levels in homes which can lead to potential health problems and mould growth may be broken down into the following categories: A. OCCUPIER IMPLEMENTED CONTROL MEASURES Examples of various control measures that may be employed by home occupiers to reduce or eliminate problems of high humidity and mould growth can include the following: Produce less moisture:    

Cover cooking pans Dry clothes outdoors Vent the tumble dryer to the outside Avoid using paraffin or flue less bottled gas heaters

Ventilate to remove moisture:    

Make use of the trickle vents on windows if fitted Ventilate all the time, especially when the home is occupied Increase natural ventilation of the kitchen and bathroom when in use and shut the internal door Ventilate cupboards, wardrobes and blocked chimneys

Heat the home a little more  

If possible, keep low background heat on all day, with natural ventilation Thermostatic radiator valves with integral timers are now available so it is possible to heat just one room for an hour or so each day.

Examples of occupier guidance notes produced by the Scottish Executive and the NHBC are included in the appendices to this report for further consideration.

B. LANDLORD IMPLEMENTED CONTROL MEASURES The following measures are not intended to be exhaustive and do not preclude other possible solutions not yet considered in this report: I.

P a g e | 11

POSITIVE INPUT VENTILATION – MAINS POWERED. An example of a mains powered positive input ventilation is a system supplied by ‘Envirovent’ which incorporates a mechanical ventilator located in an accessible roof void which distributes treated air throughout the home.

02 April 2014

“Mr Venty” Positive Input Ventilator by Envirovent limited

The treated air can be introduced at one central location e.g. the ceiling of the upstairs landing or directly into rooms which suffer the greatest problem of mould and/or condensation.

The design of the ‘Envirovent’ ventilator incorporates a control feature that draws in filtered air from the roof space or from the outside according to the ambient air temperature.

It should be noted that the manufacturers recommend the integral air filter is replaced at 12 monthly intervals.

The ventilator is designed to be operated 24/7 and may be fitted with an internal speed control and on/off switch although the company have mentioned this can give rise to problems in some social housing units.

The ventilator is connected to the home electrical supply and examples of the annual running costs are included in the appendices to this report.

A quotation for supply & installation of a mains powered ‘PIV’ unit has been obtained from the suppliers in the sum of £600 per dwelling. The quotation is based upon a minimum quantity of between 15-20 units (see appendices).

II.

POSITIVE INPUT VENTILATION – SOLAR POWERED An alternative approach to the above is to introduce treated air from outside the home via a solar powered ventilator for example the ‘Twin-Solar’ compact product supplied by GRAMMER SOLAR GmbH (see appendices for full details).

P a g e | 12

02 April 2014

Roof mounted “Twin-Solar Compact” by Grammer-Solar GmbH

Exploded view “Twin-Solar Compact” by Grammer-Solar GmbH

It should be noted that treated air shall only be introduced into the home during daylight hours although the suppliers claim that the device will still function on overcast days at a reduced output.

The suppliers recommend that the ‘Twin-Solar’ panel is installed on a pitched roof in a Southerly orientation so that the device always functions at maximum efficiency.

The unit is capable of being wall mounted and can be supplied with a duct kit so that warmed air may be ducted directly into rooms which have acute mould or condensation problems.

The principle advantage of the solar powered ventilator, of course, is that there are no running costs, however, the suppliers recommend that the integral filter is replaced at 12 monthly intervals.

P a g e | 13

02 April 2014

This represents a considerable maintenance liability especially if the device is mounted on a pitched roof and requires scaffolding to be erected for reasons of gaining safe access.

A quotation for supply only of a ‘Twin-Solar’ compact unit has been obtained from the suppliers and at the present exchange rate equates to £1,600 per dwelling (see appendices).

Please note that the quotation is based upon the Euro currency and excludes installation and carriage charges.

III.

DEHUMIDIFIERS Dehumidifiers have not been included in the list of possible solutions for reasons that they are expensive to run and from the landlord’s perspective difficult to manage and control.

The available literature on the subject appears to suggest the principal application for dehumidifiers is limited to newly constructed dwellings where there is a requirement to dry out the fabric of the building in a timely manner.

IV.

SINGLE ROOM EXTRACT VENTILATORS The properties inspected for this report were fitted with bathroom and kitchen extract ventilators and therefore comply with the requirements of Approved document ‘F’ of the Isle of Man Building Regulations.

Bathrooms, kitchens and utility rooms represent the areas of a dwelling most likely to give rise to problems of high humidity, mould and condensation and local air extractors are the preferred method of managing the problem.

Envirovent limited have introduced the ‘heatSava’ a single room heat recovery ventilator which the suppliers claim can recover up to 75% of the heat energy that would normally be lost through extraction.

“heatSava” single room heat recovery ventilator by Envirovent ltd.

P a g e | 14

02 April 2014

7. APPENDICIES 7.1 7.2 7.3 7.4 7.5 7.6 7.7

P a g e | 15

AIR TIGHTNESS TEST RESULTS HEAT LOSS CALCULATION RESULTS “DAMP & MOULD IN HOMES” (SCOTTISH EXECUTIVE) “CONDENSATION IN HOMES” (NHBC) CASE STUDY – CARTREFI CONWY HOUSING ASSOCIATION SUPPLIERS DETAILS & QUOTATION– ENVIROVENT LIMITED SUPPLIERS DETAILS & QUOTATION– GRAMMER-SOLAR GmbH

02 April 2014