[Greenbuilding] R12 for 3" of Roxul Comfortboard IS..

[Koehn Chris]

Following this discussion with some interest. Beginning stages of designing a small home with the aim of achieving Passive House using (mostly) natural- or healthy- materials.
We built a house recently using 12” deep Larsen trusses with full “chip and slip” infill with clay plaster finishes. Great material, very labour intensive, dries slowly, not the highest insulative values (a problem with Passive House).
So we’re keen to experiment with Roxul board (or other?) for a chunk of the wall, maintaining a 4-6” layer of chip and slip, presumably interior, to reap the hygroscopic benefits of the clay.

Any thoughts or experiences with such a wall?

We’re on Vancouver Island, so pretty low Delta T (at least for Canada) but nearly as many heating degree days as colder climes back east.

Cheers,

Chris Koehn