Dot and Dab and insulation question

[gingermartin]

Hi all, I'm doing a renovation project with a client and he has put silver front and back celotex insulation boards over old walls (internal stone walls) and fixed them to the wall with stud fixings. He then wants to dot and dab plaster board (12.5mm) straight onto the celotex. One section is over 20 feet high by 20 feet wide.

My question is does it stick to the silver foil. He has bought a few bags of standard dot and dab adhesive already and he wants to start this Monday. I'm concerned the silver foil is not porous enough? Thanks for any help.

[Rickyy]

I'm not convinced it will stick to it!

A bit late now, but insulated plasterboard or battening the walls would probably have been a safer bet.

[Mojooo]

sounds dodgy - why not use mechanical fixings through the plasterboard and into to the insulation

[gingermartin]

We have tried, it's a nightmare. The wall behind is stone and old, all very crumbly. Another way would be to use "chem bolts" but it would be a few days work plus the cost of chem bolts, baton and general fiddly work. But it tend to agree with prev. comments that i sounds dodgy. Somebody suggested using expan. foam....but it's a very large area.....

[mildmannered]

Dot and dab adhesive won't stick foil backed plasterboard (I've learnt).

Was the original wall plastered/flat? A lot of effort using stud fixings to attach the selotex!

I reckon your best bet to rectify now is stud out with batten. Don't forget the top and bottom first. Each batten will probably only need three screws each. If you hit a dodgy spot, try again a few inches away.

[roofer]

9.5 mm plasterboard stuck with instastik. I would double up insulation fixings first though.

[Muncher]

Pink drywall foam will do the job, but it takes a bit of holding in situ for it to set, 5 mins or so.

[gingermartin]

Thanks everyone. I think the plan will be to batten or use "insta stik".