Packing AquaPanel around shower pipes

[DoomSprout]

Hi,

We're replacing a shower cubicle, in a very tight space, which is made up of compressed straw walls (strawboard?). Due to the walls not being stud walls, our plumber wasn't able to put the copper pipes behind the wall, so they are dropping down from the ceiling along the back wall.

I'm in the process of boarding out the cubicle with AquaPanel, but I have a bit of dilemma with the back wall where the pipes are. The plumber suggested I pack the wall out with plasterboard, and then board over the top of this (I cannot batten it out with normal studs due to lack of space - we cannot afford to bring the shower tray forward that far!).

Unfortunately, the diameter of the copper pipes is very slighter larger than the thickness of the 12.5mm thick panels (by about 1 or 2mm by the look of it). Is there a way I can safely add something thin between the two layers of plasterboard to slightly increase the thickness of the packing? If there is, could someone please suggest something suitable I could use? (been thinking of maybe adding either a thin layer of tile cement, or some pvc strips, but I don't know if this is a terrible idea or not)

Thanks,

DS

Edit: Or am I maybe better off recessing the pipes very slightly into the strawboard? I didn't want to compromise the strawboard panels by cutting through the paper wrapping, but according to the Stramit site, the stuff can be routed, so I guess maybe it's OK to do this after all.

 

[catlad]

If you could dot and dab aqua panel that would give you the space you need.

 

[theoldun]

Do not attempt to dot and dab cement board to straw board with out a rake of mechanical fixings through the dabs.
Your feed will be 15mm, so two options, depending whether straw board is 12.5, 15 or 18mm thick..
Router to width required 6mm deep slot in strawboard and screw 12.5 plasterboard with slot as required over top of strawboard then fit cement panel.
OR. Cut slot as required and fit double layer 9.5mm plasterboard to straw board and then cement board.
Regards oldun

 

[DoomSprout]

Thanks both. I think routing is the way I'll go.

Another question - is there a reason I shouldn't screw cement board to the strawboard for packing, rather than plasterboard? I realise I'd be using a more expensive material than I need to, but I've got some spare cement board already.

If there's another reason other than cost (weight maybe?), I'll go and grab some plasterboard instead.

Edit: sorry, another question... For fixing the double layer of cement board, what fixings should I use? I've got 40mm AquaPanel ceramic screws, but I assume I want to use something that's long enough to go through the second layer of plasterboard and a good depth into the strawboard behind. Would I be right in thinking I need rust-proof screws of around 60mm?

 

[catlad]

Stainless steel screws will be best for wet area's and use cement board not plaster board and if you think the screws will bite in the straw board then fine.