Thermal plasterboard

[pyounger]

I have a condensation problem in our spare bedroom on the outside walls (solid, not cavity walls), so thinking about using thermal plasterboard as the existing plaster is blown under the window of the one wall.

Three questions, as I never used thermal plasterboard:

1. Do I need a vapour barrier? I notice that 22mm thermal plasterboard never mentions vapour barriers, and 30mm sometimes states that no vapour barrier is needed with this product.

2. What is the best way of hanging thermal plasterboard. I'm thinking of adhesive but read that at least 2 screw fixings should also be used - what sort of screw would be used.

3. Do I have to strip the old plaster back to bare brick, or can I apply the thermal plasterboard over the existing plastered wall

Thanks for your advice

 

[stevethespreader]

Use battens using Addy on solid walls could cause problems you can go over existing plaster