Sticking Celotex and cement board to wall?

[alex s]

Right, help needed. I have needed to remove the back ( tiled) wall of a shower cubicle in a loft conversion. The Builder had used normal plasterboard glued onto 25 mm Polystyrene that was dot and dabed onto the part brick/part block wall.
The whole lot was sodden, and fell apart as I removed the tiles.
So the plan is to use 25mm celotex, then 12mm cement backer board.
The question is how do I fix to the wall?

Cheers
Alex

 

[^woody^]

Insta Stik or Pickgrip Dry-Fix foam adhesive

 

[dextrous]

Insta Stik or Pickgrip Dry-Fix foam adhesive

Followed by screw for mechanical fixing for the backer board.

 

[alex s]

Thanks guys. didnt think about the foam fix, is it any good?
How does it compare to old fashioned dot and dabs for plasterboard?

Does it work ok on uneven walls?

 

[Richard C]

How does it compare to old fashioned dot and dabs for plasterboard?
Does it work ok on uneven walls?

Personally, I’d stick with proprietary dry wall adhesive especially on uneven walls.

I would always use a cement backer board in a wet area out of preference but the manufacturers recommend fixing to either timber stud/battens or their own very expensive proprietary framing. It can be dot & dabbed providing it’s fixed mechanically but must be fully supported or it will crack when you tighten the screws. The problem I can see is that the Celotex may not provide enough support, have you thought about using something like this, it may be a better solution in your case;

http://www.british-gypsum.com/produ...s/gyproc_thermal/gyproc_thermaline_basic.aspx

& then tanking it with this;
http://www.bal-adhesives.co.uk/products/wp1-coating