I'm just beginning to put up light framing and wood sheathing, which I plan to infill from within. I'm using board and batten siding over horizontal 2x4 nailers attached to 3x4 studs 30" o.c. roughly 1' outboard of the frame.

My question is in regards to combining woodchip clay with cellulose to boost insulation values. Has anyone on the forums done this? My thought was to infill the stud cavities (4" stud plus 2" nailer= 6" of woodchip clay) tight against the sheathing. Then I would use very light studs maybe 2x2 12" o.c. and sawn lath w/ cellulose infill. Seems like it would improve the performance of the wall quite a bit. I'm not sure what I would use to separate the two materials-- maybe some type of sheet material like burlap.

Any thoughts on putting the cellulose on the inside versus the outside? Conventional solar design wisdom would place thermal mass ***inside*** the insulation, but in terms of mitigating moisture, outside seems like the way to go. I've considered using straight cellulose-- 1' thick cellulose walls would be pretty awesome insulation. But clay seems like the perfect solution to inevitable moisture infiltration. I've also pondered mixing cellulose or some other relatively high r-value material in with the woodchip clay, though it would likely not perform as well thermally as keeping the two materials as discrete layers.

If I go the woodchip clay route, my current plan is to board and batten directly over the empty wall cavity-- no sheathing or secondary drainage plane. How are others detailing the installation of wood siding over natural enclosure systems?

-Devin Smith
Rockingham, VT