My bathroom is cold in winter and very hot in summer. I cut an exploratory hole in the ceiling and found there is no insulation, just TILE->FELT->70mm RAFTER->10mm PLASTERBOARD. This part of the roof is angled at about 35 degrees, beneath the eaves of the back of the house.
I am wondering if anybody knows of a high performance rigid insulation I could install if I take down and replace the plasterboard. I realise that as things stand at the moment, if I keep a 50mm air gap beneath the felt, I only have room for 20mm insulation (in addition to the thickness of the plasterboard). Sheets of polystyrene seem the obvious solution, but I'm not sure whether they could be described as 'high performance'.
I assume I would need to attach a vapour barrier, either separately or as foil-backed plasterboard. But would that serve any purpose if the insulation was rigid and watertight?
Look forward to reading anyone elses thoughts
I am wondering if anybody knows of a high performance rigid insulation I could install if I take down and replace the plasterboard. I realise that as things stand at the moment, if I keep a 50mm air gap beneath the felt, I only have room for 20mm insulation (in addition to the thickness of the plasterboard). Sheets of polystyrene seem the obvious solution, but I'm not sure whether they could be described as 'high performance'.
I assume I would need to attach a vapour barrier, either separately or as foil-backed plasterboard. But would that serve any purpose if the insulation was rigid and watertight?
Look forward to reading anyone elses thoughts