Hello, I have an old storage that will become a sauna.
The outer roof consists of corrugated metal, which I removed, nailed a membrane over the rafters 130-145 mm joists (old and new wood), put back the metal sheets.
Then I insulated with 145 mm stone wool insulation lying against the membrane.
I initially thought that no air gap would be needed because the roofing material is not organic, but now I'm starting to wonder if there might be a risk to the rafters. What do you think?
P.S. I won't have any vapor barrier/sauna foil in the sauna, as it won't be used very often and will remain unheated.
The outer roof consists of corrugated metal, which I removed, nailed a membrane over the rafters 130-145 mm joists (old and new wood), put back the metal sheets.
Then I insulated with 145 mm stone wool insulation lying against the membrane.
I initially thought that no air gap would be needed because the roofing material is not organic, but now I'm starting to wonder if there might be a risk to the rafters. What do you think?
P.S. I won't have any vapor barrier/sauna foil in the sauna, as it won't be used very often and will remain unheated.
