Hot take: I was sure my adobe wall needed a plastic vapor barrier until a local builder set me straight

I was fixing up my old house in the North Valley and had a big section of interior adobe wall that needed work. For months, I was dead set on putting a plastic sheet behind the new drywall, thinking it would stop any moisture. I even bought a 6 mil poly roll from the big box store last week. Then, this older guy who only works on historic homes here in ABQ saw what I was doing and just shook his head. He told me, 'You'll trap moisture in that wall and rot the wood. Adobe needs to breathe.' He explained how the old mud plaster walls work with our dry air, and that a simple latex paint is enough for a vapor retarder inside. It totally flipped my thinking. Now I'm pulling the plastic down and going with the paint. Has anyone else run into this with older Albuquerque homes?

2 comments

2 Comments

the_nathan1mo agoMost Upvoted

Honestly, that point about exterior stucco is huge. Tbh, the same breathing idea applies outside, but you have to be way more careful. A lot of the old-timers I've talked to say a traditional lime-based plaster or a really breathable modern stucco mix is key. Ngl, slapping a modern acrylic stucco over adobe can cause the same trapping problem as interior plastic. It's all about letting that wall dry outwards.

umamoore1mo ago

That builder's advice lines up with what I learned the hard way on my 1920s house near Old Town. Did he mention if the rule changes for exterior stucco over adobe, or is latex paint still the best move there too?