Thanks, much appreciated. Was worried about condensation but assume if I use something with a foil backing (foil facing up) that will barrier against any passage of water from inner side to outer side
Our house is circa 1900, stone built. Top floor is converted. One bedroom is warm enough because it's a newer dormer, but the hallway and other bedroom are cold. Both mainly have a pitched roof. Both ceilings painted but one appears to be standard plasterboard, one Styrofoam and both are pretty...