How to get rid of damp after cavity wall insulation

topsales

So I had CWI put in 6 years ago in my 1930's house not knowing then that it can cause problems. I now have constant damp patches on an interior wall on the north facing and pretty exposed wall of the house. From reading, it would seem that CWI shouldn't have been put into such a wall - aargh. The company has long vanished so I have no redress in that direction, sadly. Is there any way the problem can be helped without spending thousands of pounds - help please!!

teneighty

Before you think about having the insulation removed it is worth trying to establish the exact cause of the damp, it may be something totally unrelated such as failed cavity tray or debris on wall ties.

Does the dampness appear in any particular pattern/location or is it totally random?

Also what is the construction of the external skin of the wall, brick, block, rendered,cladding?

LisaLou1982

CWI doesnt cause dampness.

Incorrect installation may do. What sort of dampness is it? What does it look like? Where is it on the walls? What sort of pattern is it taking? Is the pointing on your property ok? Were the holes filled in? Have you checked your loft for condensation issues? Is it dripping down the cavity?

If you had it installed by a reputable company then you would have received a CIGA guarantee. If youre not sure if you have this contact them directly and they will be able to tell you.

The guarantee lasts 25 yrs and they will put the problem right if the company has now gone out of business.

faerie~spangles

Open the windows and doors.

Leif

LisaLou1982 wrote: »

CWI doesnt cause dampness.

http://www.which.co.uk/energy/saving-money/guides/how-to-buy-wall-insulation/cavity-wall-insulation-damp-problems/

Rare, but it does happen, particularly in western Scotland. And, given the freak weather we have been having, there might be more cases this year than usual.

I had damp on my kitchen wall. It soaked through from a blocked up flue, which has a cowl on top. Although the cowl has 'noses' on the side, to allow air in and keep rain out, the unusual spell of driving rain allowed damp in.

LisaLou1982

Leif wrote: »

http://www.which.co.uk/energy/saving-money/guides/how-to-buy-wall-insulation/cavity-wall-insulation-damp-problems/

Rare, but it does happen, particularly in western Scotland. And, given the freak weather we have been having, there might be more cases this year than usual.

I had damp on my kitchen wall. It soaked through from a blocked up flue, which has a cowl on top. Although the cowl has 'noses' on the side, to allow air in and keep rain out, the unusual spell of driving rain allowed damp in.

Apologies Leif - i was just about to say something else when i realised that the OP does in fact live in Scotland! The things you miss when you post at 2am eh?!

topsales

Thanks all for your replies. The house is brick built and rendered and the damp is in random patches on an exposed wall. The render is sound and there is no condensation in the loft. The holes were filled in. The damp has appeared and worsened since the CWI though the weather here has been truly awful. I will try contacting CIGA - many thanks.

teneighty

The external render makes penetrating damp much less likely so if the guarantee does not pan out it could be quite a challenge to identify the source.

The next step could be a borescope survey of the affected areas to try and see what is happening in the cavity.

Oneoftheoldies

A search on MSE Forums yesterday regarding cavity wall insulation and subsequent damp patches on walls did not reveal this thread. I submitted a post yesterday asking for information on other people's experience following cavity wall insulation. I had never experienced damp patches before having CWI installed and am now very worried about the possible effect on my house. I plan to write to the Cavity Insulation Guarantee Agency(?) for advice. Have others had help from CIGA?

Kiran

Do you rememeber what type of CWI you had installed, was it blown fibre (looks like shredded loft insulation) if so the chances are that there was debris in the cavity or mortar on the ties. This stops the fibres from being distributed and causes cold spots and then damp problems. How many patches are there that need treating?