wall insulation

[docjohn]

helo, I am renovating my bathroom and the rub is the property is quite old and has only single masonary wall - no insulation. just tiles straight on the internal side and rendered ( tyrolean ) on the outside..

I planned to add a frame to the inetrnal side and some kingspan/Celotex insulation and cap it off with plasterboard. As its a bathroom I will add a vapour barrier beteen pasterboard and insulation ..

I was planning on approx 50mm depth insulation as the room is quite small and I don't want to loose too much space ..

Any thoughts /suggestions - am I on the right track?

 

[stellaman]

50mm will be fine, Cellotex or Kingspan will do, whichever you can find cheapest. you can install a vapour barrier or use foil backed plasterboard, whichever you want to use. This isnt 100% efficient as there are still some possibilities of cold bridging through the timbers but as a cheap good room saving method this will suffice