insulating single skin for bathroom

[cwesty1]

hi i am converting a single skin (3 sides) coal shed with pre cast concrete flat roof into a bath/shower room.

what is the best way to insulate the walls, floor and ceiling to insure no damp, etc.

i figured for the walls making a 100m stud inside, filling with 100mm celotex, etc. plasterboard and skim, then tile finish.

same for the ceiling but without tiles.

is this suitable? do i need a vapour barrier also?

advice appreciated.

 

[catlad]

Google the celotex PL4000 range.

 

[cwesty1]

ok thanks, so is this all i need to use?

i work for a timber merchant so timber, celoxtex and plasterboard, etc is cheaply available so would ideally like to go down this route.

 

[cwesty1]

also i am looking to hide all the pipework within the stud

 

[catlad]

I Don't see a problem with what you propose, make sure you tape over all the stud work with foil tape to create a vapour barrier or staple a VP to your walls before you fix your plasterboard.

 

[noseall]

You are likely to get cold bridge 'shadowing' unless you fix some insulation across the studs also, prior to fixing the plasterboard.

The most recent job we did asked for a further 40mm across the timbers.

 

[cwesty1]

ok thanks noseall.
so can i fix plasterboard straight onto the celotex?
do i need an air gap at all?

sorry real beginner here.

 

[noseall]

No need for an air gap, though it would be prudent to use foil backed (duplex) plasterboards.

Have you given any thought to the roof insulation?