Critique my wall assembly! (Tstsuds, wood fiber insulation, CDX, Tyvek)
Dear GBA Brain Trust:
I am 1-3 years out from a new build, most or all self-built. While I find a lot of building science talk interesting, I get worried that some of it disguised marketing, puts homebuilding out of reach for all but higher-end pros. Having grown up in two houses built by my parents (the second one superinsulated and ahead of its time for 1990) I’d like to do the same. Priorities are simplicity of assembly, insulation, repairability, low-chemical, cost. ASHRAE climate zone 5A (coastal Rhode Island).
Kicking around ideas for a wall assembly:
– 2×8 Tstuds, 24″ o.c.
– blown-in wood fiber insulation from TimberHP (they have been saying their price point will be similar to cellulose)
– 1/2″ CDX plywood sheathing
– standard (Tyvek?) house wrap
– nonwoven fabric-type rainscreen
– either Hardi or cedar shingle exterior; cementboard or PVC trim
As of now I’m thoroughly confused over the state of the “cold sheathing problem” debate. Should I be prioritizing an insulated sheathing produce (i.e. Zip-R)? (I’m not a big fan of continuous exterior insulation. I am suspicious of a lot of layers: certainly for an amateur like me, there are a lot of opportunities to get it wrong.)
I’m also open to thoughts on Tstuds and on the new wood fiber products coming out of TimberHP.
Can answer more questions if needed. Open to all serious suggestions (as well as non-serious suggestions).
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