Insulating a 1925 stucco home
I posted a version of this question previously, but it didn’t get as much activity as I was hoping, so I’m trying again. Really hoping for Martin or Dana to weigh in here.
Climate Zone 4 (central VA). House is a 1925 balloon-frame stucco 4-square. There is blocking in the wall stud cavities in between floors. The stud cavities are not open from basement to attic like in some old balloon-frame houses.
Wall assembly is painted stucco on metal mesh>tar paper>1″ x 12″ wood plank sheathing>3.5″ open wall cavity. We have removed all of the old plaster/lath to facilitate electrical, plumbing, and insulation updates. This is a gut/rehab.
So…How should I insulate these walls?
Dense-pack cellulose and rely on its hygroscopic properties (simple)? Treat it like a house with no sheathing and build an air gap, then dense-pack (labor intensive)?
Thanks in advance.
-Travis
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Replies
Travis,
Is this you under another user name?
https://www.greenbuildingadvisor.com/question/insulating-a-1920-balloon-frame-house-with-stucco-exterior
Nope, that's not me. Very similar circumstances though. The responses there seem to be somewhat contradictory, which is what I've also found while looking through old posts. Hoping to get more a more definitive answer than they did. Maybe wishful thinking.
Sounds like you have the same situation as I do. See my 3-16-23 post re Victorian with stucco. I am currently planning to create an air gap with spacers and 1" - 2" of EPS or XPS and can foam around the edges, then R-15 rockwool. I am in zone 4C marine, NW of Seattle on the Kitsap peninsula. Curious to know what you did. My approach is certainly the most labor intensive. I took cues from a Fine Homebuilding article on insulating a house with no sheathing as I think you mention. I am definitely open to an easier solution though assuming no risk of condensation and attendant rot.