I'm going to start my renovation of the upper floor of a brick and plaster house from 1906. I will be taking down all the ceiling (Tretex) and wallpaper on the upper floor. I'm debating whether to add extra insulation while I'm at it. I don't want to add extra insulation on the outside. My option would be to tear everything down to the brick and then build up with steel studs, 45 mm insulation, and drywall.
Is it worth adding 45 mm insulation for a roughly 30 m2 outer wall?
Should I have a vapor barrier behind the drywall?
How do I create an air gap between the brick and the insulation?
If I don't add extra insulation, should I just skim coat the walls and paint? What materials can be applied to such a wall, Microlite, fabric wallpaper, etc.?
For the ceiling, I plan to use furring, place a vapor barrier, and drywall. (The vapor barrier is to prevent indoor moisture from going up into the attic).
What else do I need to consider?
