dot and dab insulated plaster board on solid wall - ok?

With the dob and stick method you're literally making the plasterboard part of the wall again, which is not what you want to do if you want to insulate it. To make any kind of insulation you need a space in between to create an air gap that holds the heat in. The gap can be filled with material that helps this happen.

I live in an old cottage - solid walls - probably more than 9". Current plasterboard fixed to a frame but needs to be replaced. Builder recommended removing existing plasterboard and frame, making good (and level) the walls with a sand and cement plaster and then using dot and dab to line with plasterboard. He recommended using insulated plasterboard (i.e. plasterboard damp proof membrane and 1-2 inches of insulation bonded to it.

Job not started yet, but thats the plan

Hope this helps

Frank.

even for insulated plasterboard? Even for regular plasterboard there will be a gap with dot and dab, unless you really skimp on the adhesive. Neil

Insulating plasterboard with foam stuck on the backside of it, is not really suitable for the dob and stick method of fixing, mainly because the foam is soft and if pressed will eventually loosen and pull off the wall leaving the foam behind. If you don't believe me, try it.

To insulate properly, you need to leave as even a gap as possible all over the surface. This is more easily done with timber or aluminium studs covered with a foil backed plasterboard. If you need to retain even more heat, then a filler with the correct properties in between the studs and sealed in with plasterboard to create a sandwich is the most effective way of doing it.