Cavity Wall Insulation and Condensation

[horseshoes]

We had cavity wall insulation a couple of years ago and we now have the problem with the dreaded condensation ie water on the inside of the windows and horrible back spots. Help please. What can we do?

[mjwman]

You need to introduce some ventilation. Open a small window or two or install a vent in the wall.

[jomifl]

A dehumidifier, (electric not a chemical one).If you maintain your humidity below 60% your problem will vanish. You just need to put it in the worst affected room and leave the doors open when it is runniing. The electricity that it uses will end up as heat for your house so not that expensive to run.

[horseshoes]

Thank you both. I'm just glad to know it can be solved!

[Hopkirk]

.. and treat those black spots asap.

Bleach doesn't kill it, get some proper stuff:

http://www.nevillesdi...move-mould-2542-p.jpg

[jomifl]

If you reduce the humidity as described above then the black mould will die and may well just brush off, otherwise a paint job is the answer.

[The Builder]

One consolation, Horsey. Without the cavity insulation it would be a whole lot worse :o(

Easily fixed....... extractor fan directly above the shower or bath ...... ducted to the outside (in the roofspace).

[horseshoes]

Actually, it's not in the bathroom at all! It's in the living room which is a 100+ year old cottage with huge thick walls, so there's no cavity walls in that part of the house. It's in the bedrooms (which is a new part). I've been wanting to change the windows for ages 'cos they're just 2 big panes and don't a small opening part. I'm always terrified of the cat falling out so they don't get left open much at all. That may well be the good excuse to get them replaced now. Thank you all again.