What to put under wood siding?

Old 12-17-15, 07:17 PM
Thread Starter
Join Date: Sep 2013
Location: USA
Posts: 19
Received 0 Upvotes on 0 Posts
Question What to put under wood siding?

Just finished framing a 12' x 12' building near my pool to use as a changing room during swim season and storage the rest of the time. I'm going to cover it with plywood siding and may insulate it to keep liquids from freezing during winter but it won't be heated or cooled. It will have 2 insulated windows and an insulated door.

Would like for it to not be drafty so am thinking about house wrap (Tyvek), tar paper or some kind of wrap before the siding. I'm thinking tar paper could be be a problem with insulation since it serves as a vapor barrier and Tyvek would be good either way.

Old 12-17-15, 08:26 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Posts: 27,314
Received 1,977 Upvotes on 1,772 Posts
Tar paper is not a vapor barrier. #15 felt has a perm rating of around 5, so it is considered semi permeable... meaning if it gets wet, things can dry to the inside or out, depending. People have used felt successfully for years, so I would not be afraid to use it. Its a lot cheaper.

The benefit of Tyvek is larger rolls, and flashing tape sticks to it. It will still be drafty unless you follow the instructions and install it as an air barrier, taping all edges.

Also, insulation alone will not keep an unheated building from freezing. Kiss your paint goodbye if you put it out there in the winter unheated.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: