Internal wall insulation - as thin as possible?

moneysaver1978

A relative was asking about how to make a single wall warmer. There's a small bedroom in the corner of the house (1 wall above the garage) and in winter time, that wall is very cold on touch.

As it's a small bedroom, there is nowhere else for a bed to be positioned except against that wall (sideways). I suggested something like Celotex 25mm PIR but unfortunately that's still a bit too thick.

He is sure it is a cavity wall and the previous owner had the cavity filled 20 years ago or so.

Is a thermal wall paper worth doing or should he get someone to look into the cavity from outside?

I attach a photo - not his house but the layout is similar and no pipes on that wall.

FreeBear

moneysaver1978 said:

A relative was asking about how to make a single wall warmer. There's a small bedroom in the corner of the house (1 wall above the garage) and in winter time, that wall is very cold on touch.

As it's a small bedroom, there is nowhere else for a bed to be positioned except against that wall (sideways). I suggested something like Celotex 25mm PIR but unfortunately that's still a bit too thick.

I have a small box room some 2.4m by 2.7m with two external walls. Put 75mm of Celotex on both walls, and to be honest, can't notice the difference in size. It has made a huge difference to the space - No more condensation on the walls, and can be heated with a tiny little ~700W radiator. Having a new DG window plus extra loft insulation has also helped in keeping the room warm.