I am working on a small extension to a year-round cabin.
The house is from the late '80s and consists of a wooden frame on an open pier foundation.
There is a vapor barrier, as far as I can see, on all exterior walls and against the roof insulation, which is also how I plan to do in the extension.
However, it seems that no plastic was laid under the floor. Is this normal, and how is this justified if so? The pier foundation is open and therefore relatively well-ventilated. The beams rest on the piers and then the floor joist, insulated against the pier foundation with a subfloor board and 145mm insulation.
Opinions on vapor barrier in the floor?
