I’ve recently had my basement “waterproofed”, which included among other things and interior drainage system and a 120 mil thick moisture barrier on the exterior walls. I’ve since framed it all in with the framing about 2 inches off the walls. The framing goes up to the ceiling, will not be finished and will be left exposed (its already painted black.)
I’m getting conflicting advice on how to insulate. Specifically, whether or not another vapor barrier should be installed. I live in southeast Michigan.
Any help is much appreciated.
Replies
I would not put another vapor barrier in. check the codes enforcement folks where you live. mostly a no no.
If you do not intend to finish the wall, or cover it, what kinds of insulation are you contemplating?
You should be aware of firestop requirements, to keep the area behind the wall from being a problem in case of fire.
Thanks UncleMike42. Will be covering the wall with barnwood on top and corrugated steel on the bottom. Was thinking plain old r13 fiberglass, hopefully on sale somewhere.
DO NOT add a second vapor barrier. I researched this topic deeply a few years ago when writing this article for FHB: https://www.finehomebuilding.com/2005/03/01/the-no-mold-finished-basement
A second VB will trap moisture and you'll rot the framing. Also, something I learned from Mike Guertin's article on fireblocking in the current issue (https://www.finehomebuilding.com/project-guides/framing/7-common-fireblocking-locations) is that with this kind of assembly, you need to install horizontal fireblocking between the wall and a stud every 10 feet. That fireblocking can simply be Roxul bats.
Thanks Andy. Both those articles are great, with the fireblocking one adding more items to the to do list.
Good article Andy. Those of us in commercial building deal with this on a daily basis and it's good to see the residential code being updated, however it will take a long time for remodelers and do-it-yourselfers to catch up.