Outer insulation stone walls - European product - any good?

[Chaz11]

Hello,

Just wondering what people's experiences are of insulation applied to the exterior of old stone walls? It's relatively new in the UK. It apparently totals 70mm in thickness, consisting of 3 different layers. In theory, it is the ideal solution to old stone houses that have no cavity, and where battoning and plasterboarding with insulation would lose too much space on the inside.

Has this product greatly increased anyone's thermal conservation, as well as removed the usual cold ingress problem? (cold wall surface + moisture in the air = damp and mould).

I'd be interested to hear any info at all on this, as we're considering it for our stone cottage.

Cheers and many thanks
Charles

[Perry525]

The fact is, that heat always moves to cold, as indeed does water vapour.
If you add insulation to the outside of a wall (or anything else for that matter) the walls will still soak up most of your heat.
If you are retired, or live and work at home, and keep your heating on 24/7 thoughout the year, then putting the insulation on the outside, may help to keep you warm, but it won't do much good.
Insulation needs to be on the warm side of your walls.
Try putting your hand on a piece of polystyrene and feel the warm reflected back, then put your hand on your wall, the wall will always feel cold, even if you manage to get it up to 22C.