wood shingles over foam board
I’ve seen some related posts, but here’s my issue. The 1925 house has cedar shingle siding, and the south face needs replacement. I’m planning a full strip (on that face), blow in dense-pack cellulose to the empty plaster/lath walls, then add foam board to break the thermal bridge plus give a vapor seal.
Building Science shows what to do with strip siding (vinyl, alum, or clapboard), but what do I do with shingles?
The issue is an air break between the siding and the foam board. Furring wouldn’t really work with shingles. Is there some kind of screen material or dimpled membrane that could be attached in sheets to the foam layer? Would felt paper be enough?
How important is the air-gap/drainage-plane? Could I just attach to the foam board without the gap?
While I’m at it, is 1″ XPS the right foam? Will the shingles hold over everything using long ring-shanks, or can I get by without ring-shanks (hard to pull out, if the siding needs to be redone)? Note that the sheathing was tongue-in-grove, but with years of shrinkage, it’s more like plank-with-gaps, and probably somewhat brittle with age.
Am I missing anything?