Is cavity wall insulation the cause of my black mould?

Abbafan1972

We suffer terribly with black mould in the bedroom, bathroom and have now spotted a small patch of it in the my girls' room.

Basically it's the rooms that have high levels of moisture and in particular the bathroom just never seems to dry out.

We had cavity wall insulation done about 7-8 years ago and think that this has started happening since we had it done (have lived here since 1995 and have never noticed it being a problem before).

This is really doing my head in and could the cavity wall insulation be a cause of this?

Leif

It sounds like condensation. Do you have a ventilation fan in the bathroom? It is now mandatory when you have a bathroom redone to include a fan that turns on when you turn on the light, and stays on for a set time after you turn the light off. That would be the simplest way to improve ventilation.

I am not in the least bit an expert, actually not knowledgeable at all (you have been warned) but I would naively expect cavity wall insulation to warm the inside walls, and hence reduce the likelihood of condensation. Condensation occurs, of course, when warm moist air hits a cold surface, such as a window or a cold wall.

Do you take more baths/showers? Do you have children who are older now, hence more washing, more showers etc?

Note added: Oops, it is just the damp air that is the issue, not so much condensation, but the information above still applies i.e. what is the source of the damp?

macman

Mould is a result of higher humidity levels caused by lack of ventilation.
So you need to improve the ventilation.

withabix

Cavity wall insulation can cause damp problems due to moisture transfer if your brick ties are bridged by mortar. Filling cavities with mortar on the brick ties can allow moisture to pass across the brick ties, as it will no longer evaporate in the cavity or drip off down to the cavity tray.

Reputable installers drill holes in your walls and do a fibre-optic camera survey to check your brick ties before they will do with work.

If you have mortar on your brick ties, they will refuse the job.

Leif

macman wrote: »

Mould is a result of higher humidity levels caused by lack of ventilation.
So you need to improve the ventilation.

And/or remove the source of high humidity.

nickj_2

you might need something like this http://www.condensationshop.com/home/

ListysDad

OP
Read this thread.
https://forums.moneysavingexpert.com/discussion/3750855

cyclonebri1

;)Ventilation every time, unfortunately removing the source of condensation involves killing all living beings in the house, :eek::eek: and stopping cooking washing up etc

We have 1 room in the house, (bungalow), that suffers from that dank mouldy smell. Bungalows are notorious for this due to having both a cold floor and a cold roof in the the place unlike a house.
No different since we had the walls filled 13 years ago, no better, no worse. That room isn't used so it's just the fact that it is shut up all the time but moisture from the rest of the house permeates in and results in the smell, at the moment I don't need to sort it but will when it comes to sell.

Ventilate.

In our bedroom we have a 4" fan installed in the top of two fitted wardrobes to ensure clothes stay fresh, grills in the base. Comes on with the bedroom light so not extravagant.

I think standard practise would be to have an additional ventilation brick installed in each of the affected rooms,

[Deleted User]

dh a structural engineer had to deal with the after effects of cavity wall insulation many times in his career

http://www.premier-heritage.co.uk/2009/08/cavity-wall-insulation-what-are-the-benefits/

foam cwi is a time bomb, at least rockwool can be sucked out

He got fed up of telling local authorities that cwi was the wrong thing to do

http://www.premier-heritage.co.uk/2009/08/cavity-wall-insulation-what-are-the-benefits/

dh says that it is impossible to suck it all out and blobs will be left. The only thing to do is to externally insulate

aeb_2

We moved into a house with cavity walls built in 1908 and two bedrooms suffered from black mould. We installed a simple air brick into all the bedrooms and the problems was solved.

We never had cavity wall insulation because of the 'time bomb' factor in such an old property which was designed to be ventilated with suspended floors, coal fires and sash windows. Even sucking 'wool' out would have been an expence.

cyclonebri1

kittie wrote: »

dh a structural engineer had to deal with the after effects of cavity wall insulation many times in his career

http://www.premier-heritage.co.uk/2009/08/cavity-wall-insulation-what-are-the-benefits/

foam cwi is a time bomb, at least rockwool can be sucked out

He got fed up of telling local authorities that cwi was the wrong thing to do

http://www.premier-heritage.co.uk/2009/08/cavity-wall-insulation-what-are-the-benefits/

dh says that it is impossible to suck it all out and blobs will be left. The only thing to do is to externally insulate

Can rockwool insulation be topped up in that case, I only ask as when we had it installed I was never convinced it was done correctly, as the company involved folded within a year inspite of our 25 year waranty.