Insulating stone wall - too many options!

[derekwinton]

Hi,

I'm a bit of a noob so apologies if any of this is daft.

I would like to plaster the inside of an 18 inch exterior stone wall and thought it would make sense to insulate at the same time.

The celotex / yelofoam insulation boards seem like a good idea but from this and other internet resources there seem to be various options and my head is spinning a bit!

1. Batten -> Insulation -> Plasterboard
2. Batten -> Insulation -> Moisture Barrier -> Plasterboard
3. Insulation -> Batten -> Plasterboard
4. Moisture Barrier -> (air gap) -> stud frame inc insulation -> Plasterboard

The main priority for me is keeping it simple and I'm happy to spend a wee bit more if it saves hassle.

Option 1 looks simplest but do I need a moisture barrier?

Thanks!

 

[Grenage]

If the wall gets damp in harsh weather, you'd need a breathable membrane or a cavity, preferably the latter - I believe.

If the wall doesn't get damp, you can generally get away with throwing stud straight onto the wall, filling it with insulation, and boarding over. You need a vapour barrier on the warm side, to stop any internal moisture making its way to the wall. You can get insulated plasterboard with a foil backing - that foil can be used as your vapour barrier.

To keep it simple, this is what I did when I insulated my single skin cupboard:

Wall
Breather membrane (simple roofing breather)
Stud + 50mm Celotex
Celotex 12mm TB4000 (reduce thermal bridging) + tape on the foil joins
Plasterboard.

Space was at a premium, so I didn't leave the cavity I would have liked; it's made the world of difference. Don't forget to plan ahead for anything you intend to attach to the wall.