DIYbanter - View Single Post - Stopping condensation on underside of asbestos outhouse roof...

Harry Bloomfield[_3_]

has brought this to us :
You need to reduce RH. Your condensation has nothing to do with the roof's
coatings. There are 3 ways to reduce RH:

It can have a lot to do with lack of any insulation. My garage and
adjacent workshop I fitted with a modern corrugated metal roof. In
colder weather lots of condensation would drip from the underside. It
was much worse in icy weather, when ice would build up, then thaw as
the weather warmed. I fixed it entirely by the addition of fire
retardant expanded polystyrene insulation sheets, pushed up tight
against the underside.