Insulation for bathroom wall

[Steve]

I have a double-brick wall house, no cavity. The bathroom, as it has a large expanse of external wall on the side of the house which is all tiled, currently gathers a lot of condensation.

When I replace the bathroom, I will install a fan, but also want to insulate this wall internally. What is the best way to do this, given I want to tile it when finished? It can be up to 50mm thick. The bathroom is fairly spacious so I can afford to loose this space.

I had thought about erecting a studwork frame with insulation between the studs and boarding it (but what with), and I know there are products available (plasterboard with insulation attached?) for this purpose.

The wall will be fully tiled, and will hold a mirror, towel rail, WC and basin.

 

[Deluks]

There are different types of insulated plasterboard, cheaper stuff from under £20 a sheet, and something like kingspan k17/k18, which is about twice as much. Obviously the more expensive one gives better performance, but depends how much a tight yorkshireman wants to spend. I don't believe in going mad on bathroom wall insulation as they tend to become warm enough when you've just stepped out of the shower or bath.

insulated aquapanel or marmox board (available in varying thicknesses) will be useful if you want to tile straight onto it.

An insulation/wbp ply/plasterboard sandwich might be worthwhile if you are fixing a basin to it.