Insulation Behind Rafters of Pitched Roof and Eaves Storage Area
Posted: Thu Oct 10, 2019 9:42 am
Our first floor is in the pitched roof with storage areas at the edges of the rooms. Our roof insulation is old and dirty rock wool fitted behind the rafters, up against a membrane. This is all the way down the rafters behind the inaccessible sloping walls in the rooms so it was likely to have been built that way (1980). I have found water stains on things in the storage space before, but not sure if this is condensation, rain getting in or mouse pee! I want to improve the insulation and make a clean space and was thinking of adding celotex between the rafters, then boarding over with thin ply. Should I remove the rockwool where I can, leaving an air gap between the membrane and the celotex, or leave the rockwool in? Would it be overkill with celotex on the floor too?