Plasterboarding Bathroom

[fadedfish]

I am about to embark on a project to fit a new bathroom suite. This is somewhat complicated by the fact that the existing plaster in the bathroom has perished such that large sections came off the wall to reveal bare brick. The existing tiles are still up but when I remove them I fully expect the same to happen there.

I have been advised to install insulated plasterboard to the outer walls (brick), and moisture resistant plasterboard to the other walls (studded - currently plaster and lath). The reasoning behind the insulated boards to the outer walls is that it will reduce condensation on the tiles - does this sound sensible? Also we intend to tile each of these walls - will fixing the insulated plasterboard by dot and dab be sufficient or will I need to add other fixings?

Any help will be greatly appreciated

 

[flameport]

Adding insulation is fine, but NOT for reducing condensation - that is resolved by improved ventilation.

Plasterboard with tiles over it is not suitable if you have a shower or other areas exposed to significant amounts of water - the board will just fall to pieces. Those areas should have cement boards.

Dot and dab may be enough for lightweight finishes, but for heavy tiles mechanical fixings should be used. Again, plasterboard is the wrong material if you are using thick/heavy tiles over it.

 

[fadedfish]

Thanks for your reply flameport. I think I'll just use moistureboard all round if the insulation is not going to have the desired effect - I have precious little room to fit the bath as it is! I am having ventilation fitted and there is only an over-bath shower so it shouldn't get too damp. Will I need to tape the joints on the boards if I am tiling floor to ceiling?

 

[longdogs]

You can get away with moisture resistant plasterboard (the green stuff) but cement board is better. If at any time the grout fails and the board gets wet, it will still hold it's shape. Either way, fix with screws to the frame and use plasterboard tape over any joints (using flexible tile adhesive) immediately before tiling.