Anyone back-vented Hardie lap siding over exterior insulation?
At this point we plan on building a 2×4 wall with dense pack cellulose (r-12), then 1/2″ plywood, 2 layers of 2″ fiber faced polyiso (r-26), WRB, 1×3 strapping and then siding. Can we use Hardie lap or Hardie panel siding? Likely a question for Hardie but they will likely say they want direct contact with sheathing and if foam, then no more than 1″ thick. Their install instructions imply direct contact with sheathing but I don’t see any restrictions against fastening to strapping….but maybe I missed that. Also, i’m guessing that strapping 1′ O.C. would make the most sense to reduce/eliminate deforming of the slightly floppy fiber-cement? Anyone done anything like this? Maybe this has been addressed but I didn’t find it when doing searches thru the QA section. Oh, and I would assume strapping desirable since wind blown rains will get behind the siding and it’ll never drain/dry if siding is tight to sheathing on a high-r-value wall…?
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