leaning wall: leave gaps behind or in front of insulation?

[RobertL]

I am insulating the inside of an existing external wall. It leans slightly= outwards. My internal (70mm deep) studs are vertical and the insulation = goes between them, and plasterboard will go on top. Building control have a= proved the thickness of insluation. Wall is 100mm thick concrete block.

The insulation (Ecotherm =3D Celtotex type of stuff) wedges between the stu= ds but there is a gap behind it increasing with height because the wall lea= ns out but my studs are vertical.

Would it be better (1) to press the insulation right back against the wall = and leave the gap immediately behind the plasterboard, or (2) have the fron= t of the insulation flush with the front of the studs leaving a gap between= insulation and exterior wall. Maybe (3) it does not matter.

The gap varies from 0mm at the bottom to about 50mm at the top.

Opinions anyone?

thanks,

Robert

[Dave Liquorice]

2. A single block wall will be damp, maybe not a lot but it will be you need some ventilation to get rid of the damp.

You don't mention a vapour barrier, that needs to be on the warm side of the insulation. It will be easier to tape the joints (board to board and board to studs) if everything is flush.

[geraldthehamster]

Yes, I agree. I'd keep the insulation in line with the front of the studs. Have done, in fact, and fixed it there with expanding foam round the edges for an airtight fit.

Cheers Richard