Moisture Concerns in “Straw-Cell” wall in Climate Zone 4A
I am planning a “straw cell” house (see attached drawings) and love the “Pretty Good House” criteria. I have been reading a lot about double-stud cellulose walls b/c I can’t find that much research specifically on “straw-cell,” but I figure they might behave similarly.
Details and questions below.
Thanks in advance!
-Location: Columbia, Missouri – northern end of Climate 4A
-Size: 576 sf footprint (with 288 sf loft)
-Wall Assembly: load bearing 2x4s w/ dense pack cellulose; interior of that straw bales laid on-edge with earthen plaster on inside; zip sheathing; rainscreen siding
-ERV: 1 or 2 Lunos eGO in-wall units
-Dehumidifer: one in bathroom, make & model TBD
1. Is it crazy to build like this in 4A? I sense that moisture condensing on sheathing in super-thick cellulose walls is of greatest concern in colder climates (like zone 5?)
2. How significant is the lack of latex paint on the interior? Paint seems to be key in controlling vapor in double-stud-cellulose walls. Obviously, I’m not going to paint earthen plaster.
3. Would using plywood sheathing instead of Zip be advised? If so, what is most affordable liquid-applied or membrane product to air-seal the plywood?
4. I am interested in installing moisture / temp sensors in wall to measure over time (as a citizen scientist). Suggestions on products / methods for doing this?
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