Question from Gigi
We will be laying down Bellawood hardwood flooring with nails.
We will be laying down Exterior grade plywood over the top of an existing plywood subfloor. This is located over a crawlspace. The old tar paper has to come up. What we need to know what are our options regarding a moisture barrier? I read that the exterior grade plywood is considered a moisture repellant, according to wikipedia. Does this mean we can bypass placing tar paper between the plywood? Do I need a tar paper moisture barrier if I use exterior grade plywood underlayment? If we have to use tar paper, then what can we do to minimize the off-gassing?
Debra’s Answer
This question is a little more technical than I have experience with. I’ve laid a lot of hardwood floors, but never needed to use a moisture barrier.
I wouldn’t use tar paper. Can you use Tyvek? This is a plastic but it is very nontoxic.
Readers, what moisture barriers have you used under wood floors?
I’m trying to decide now between the 3 options my contractor gave me: tar paper, red rosin, or silicone paper underlayment. Based on what I’ve read so far, I’ve eliminated tar paper from my options. I’d love to hear if anyone has had any experience, good or bad, with the other two.