wall insulation

[mellis]

Hi

We've just moved to a mid-terraced house built in 1880. The kitchen sticks out the back so has three walls exposed to the elements. The house has solid walls - the main ones are really thick with lath+plaster inside, but the ones on the kitchen relatively thin.

We're going to take out the old kitchen and out in a new one. I'd like to insulate the walls. I'd propose fitting kingspan/celotex as I need to not lose too much of the width of the room!

Should I just build out from one corner, putting battens every 450mm and wedging the celotex in between? Then ensure I have a complete vapour barrier on the warm side by using foil tape over any holes + over the battens? Then fix the plaster board on the inside?

Is it ok to use dabs of glue/expanding foam to stick the celotex to the walls, or should there be an air-gap?

Many hanks! Mark.

 

[foxhole]

You could just line with insulated plasterboard, you will need noggins installed where wall cup'ds are to be mounted.

 

[mellis]

I could ... but insulated plasterboard is more expensive. And is it still ok/not ok to stick it to the stone wall or does it have to be on [thin] battens so there's an air gap?

Other question actually is about fitting sockets/electrics. Doesn't the hole for these completely destroy the point of the vapour barrier!?