Paint Permeability for Clapboard
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I have a 150 year old house. I recently removed the aluminum siding and am restoring the original wood clapboard. I presume I should use a breathable / permeable paint when it comes time for painting. How permeable should it be?
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Replies
Most modern acrylic based exterior paints are very permeable, and durable.
Benjamin Moore's "Regal" line is quoted at ~50 perm
https://media.benjaminmoore.com/WebServices/prod/assets/production/datasheets/TDS_0103/20210706_W103_TDS_US_OKF.pdf
Sherwin Williams doesn't seem to share that info in their tech docs, but I'm sure it's up there too.
There's not a lot of control in choosing a desired permeability - just go with a good paint, apply it well, and it'll perform as good as anything else you could have applied.
I believe Sherwin Williams puts their Super paints at ~27 perms and their Emerald at ~29 perms. Is that sufficient?
Yes, that is sufficient.
Anything over 10 perms is considered to be very vapor-open, and will allow drying when the conditions are right.