a friend who happens to do home improvements recommends installing insulation on the underside of the roof. From within the attic of course. I haven't been able to find a thing that suggests doin so or not. All I've been able to assess is that by doing so may risk rotting the wood perhaps of the roof. the insulation has vapor barrier paper or batting with paper on the bottom towards living space.
His thinking is that keep the heat from entering the attic. Id have to aggree, but why is it that I don't see this practiced in any other houses. I know that installing the insulation on the underside of the roof is an incredibly tedious and difficult thing ? anyone have comments