Worried about Condensation

holdfast

I am looking at a project where the construction is a timber frame 5 years old and the owner want to add more insulation. I was going to recommened kingspan K18 board to be attched directly tot he existing wall. But now the existing plasterboard is foil backed and its a vapour barrrier. what do other people think about the possibility of inter. condensation with this solution.

sydthebeat

If you 'dryline' with any insulation, you should try to make it breathable.. ie like softboard or a hemp type material.

Pu and PIR is better performing but is non breathable and bad at diffusing moisture.

edit: you can use buildesk uk as a free software for calculating risk of interstitial condensation.

ircoha

holdfast wrote: »

I am looking at a project where the construction is a timber frame 5 years old and the owner want to add more insulation. I was going to recommened kingspan K18 board to be attched directly tot he existing wall. But now the existing plasterboard is foil backed and its a vapour barrrier. what do other people think about the possibility of inter. condensation with this solution.

It MIGHT be worth getting some Thermal image pics taken as the problem may be that the isul has sagged and therefore it maybe worth fixing properly. This is an increasing problem with TF, was reading about it a few weks ago, will try find the link again.

holdfast

thanks I will look at both. the existing insulation seems to be in place as you would expect some thermal bridging following a survey with the camera.