OSB as Vapor Barrier
I’m running into an issue with a build here where I need a warm side vapor barrier on an overhang.
Figured I was being smart and skipped poly since 3/4″ OSB is around 0.5 perm, but now my inspector is asking for a spec sheet showing that it has been tested to ASTM E96 / E96M.
I searched through the spec sheet of most major OSB manufacturers and none of them have a perm rating in their data sheets. Lots of into about spans and nailing but that is about it.
Anybody run into this and how did you get around it? I’m guessing I’ll have to pull up the floor and install the poly but it just seems silly.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part