My house is located in a cold climate and the usual rule is to place the
vapor barrier on the inside of the insulated walls. I am adding radiant
heating on a thin slab with insulated joist below. The floor sheathing and
flooring acts as the vapor barrier to the warm heated side, but what do you
do at the outside walls where the joists are located?
Do you put vapor barrier on the rim joists/blocking, put nothing, just air
barrier, only caulking? Or do you put insulation next to the rim joist,
then vapor barrier and then insulation in the joist space?