One of Housing association clients had been back to this property after doing various mould sterilisation treatments that haven’t worked. The tenant had complained that the problem was coming back. We were asked to come up with a scheme of works to rectify the problem.
On site assessment
The mould problem was contained to the upstairs rooms of the property and mostly around the perimeter of the upstairs ceilings in localised patches and the loft hatch at the top of the stairs. The first thing I did was to do visual inspection of the outside of the property to look for external defects and it appeared to be in reasonable condition.
On the internal of the property with mould patterns being in specific places areas of the ceilings my first port of call was to look in the loft and see if the roof space was ventilated correctly which it was, the loft hatch was not insulated on the back and it was poorly fitted and the tenants told me they could feel a draft coming through this when it was windy. This was causing a cold area around the loft hatch.
Next check was to see if the insulation was installed correctly and would you believe it there were areas missing in exactly the areas the mould was forming underneath. It was apparent that someone had boarded area for storage and had moved the insulation whist up there. The tenant did confirm that his son had boarded the loft section to store stuff on.
I then moved onto the extractor fans. The type installed were continuous running centrifugal extractor fans with boost activated by the integral pullcord. I got readings in the bathroom of 1.8 litres per second on constant and 3.2 litres per second on boost. Very low for a fan of this type. The kitchen area was a little better with scores of 4.5 on constant and 5.6 on boost but still nowhere near the amount needed in this area. (all readings done on a fully calibrated TESTO 417 Vane anemometer with funnel) Because the flow rates were so low I decided to do a little more investigation work (with written permission from the client of course)
First I took out the plastic filter and front cover of the bathroom fan and found it to covered in dust and grime, this often happens with extract fans in wet areas due to the fact that steam is pulled through and it leaves behind dust and airborne particles these get stuck to the parts inside. This will seriously slow down the airflow, also, after looking at the outside of the property again I noticed that the external covers were the wrong type for this type of extractor. A previous contractor had used fixed louvre vents with fly screens in, these should have been the flap type for this model.
Then I looked at the kitchen fan and it was much of the same, dirt, grime, only on this one I could take the external cover off safely and confirm it was solid ducting used to install them which is always preferable. I took the front cover off the fan and took out the fly screen and retested the airflow, I got readings of over 30 litres per second which is adequate for where the fan was situated.
Scope of Works to Carry out
• Clean the fans, install new foam filters and install the correct external covers
• Relay the insulation in the correct areas
• Clean down all areas of black mould using correct mould sterilisation fluid and redecorate using an anti-fungal paint
• Provide Tenant with information on how to naturally ventilate there home
• Do a second inspection at a later date to confirm issues are resolved.
Needless to say, the client was very happy with the out come of this survey. And the tenant is also happy he will no longer need to live with the black mould issue, a happy outcome all round.
if anyone is in need of speedy reliable surveys and remedial treatments for anything damp related