I'm building a house and have been told that a tar paper sheath has to go under and between the stud walls and the concrete wall and floor. This seems to me overkill as there will be a plastic vapour barrier on top of the insulation. The source material that I'm referring to for information on how to build the stud walls never mentioned anything like this, and I mostly have the walls built already. AAck! With some fiddling around I can get the tar paper behind the walls, but not underneath without A LOT of trouble and extra expense.
Answer:
The tarpaper on the concrete wall was removed even from the 'minimum standards' building code some years ago so you might be dealing with a local bylaw that is somewhat behind the times. I've not heard of tarpaper being necessary under the sole plate but I have heard of 6 mm poly being used there. Again, local bylaws might be putting you in a rough spot so I'd check it out.
