Breathable Paint for wooden joists
1000
| Posted in General Questions on
Hi all,
Looking for a breathable paint that’s sprayable for the wooden joists for the basement of a 1940’s building in the suburbs of Philly.
I’m rehabbing the 4 unit property and converting one of the basements into my shop space. The walls have been cared and lime washed – doesn’t look like they’ve ever seen latex paint or drylok, and there’s not too much moisture in the basement.
Hoping to find a breathable paint that we can spray the underside of the subfloor and the pocketed floor joists. Maybe I’m looking too far into things?
Sasha
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
What do you mean by breathable?
Something with a high perm rating that won't trap moisture in the pocketed joists!
The basement is in great condition and I don't want to compromise its longevity for aesthetics.
Sasha,
Primer is about 6 perms. regular latex paint is about 5.
I doubt it's sprayable but I just wanted to mention the option of limewash. It's highly permeable and also has benefits with regard to mold and pests.
https://www.nps.gov/articles/limewash-an-old-practice-and-a-good-one.htm
Check out the specifications for mineral paint. I am studying this for a project where I need a very vapor open interior finish.
https://www.keim-usa.com/Product-Categories/Concrete-Systems/What-Makes-Mineral-Paint-Best-for-Concrete/Mineral-Paint-is-Very-Vapor-Permeable#:~:text=Mineral%20paints%20and%20stains%20allow,trapping%20moisture%20within%20the%20concrete.
I agree — Mineral Paint is just about the most-open form of covering. Milk Paint is also an option that outperforms Latex. Here's a rundown. (Trust but verify — this isn't a peer-reviewed scientific journal) https://www.mychemicalfreehouse.net/2021/01/breathable-paints-high-perm-rating-wall-coatings.html
I saw this article too, have been calling up some of the companies but having trouble finding credible perm ratings. will follow up when I do!
We're big fans of KEIM, but my understanding is that their coatings aren't suitable for wood. We just shot a video with their rep about painting our brick facade with mineral paint!