Kat Cearns wrote:Mid-Vancouver Islander here (for sake of climate info)-
I'm wondering if I can pick your collective brain about cob/slipstraw building- retrofitting a stick-frame 20'x30' building with a trussed roof on a cement pad. There is plywood on the exterior and, apparently, it's structural, so I'm not allowed to remove it. We're trying to figure out if there is a safe way to insulate the walls and roof of this shack without using synthetic materials which will off-gas or get all up in my nose, eyes, skin, and throat with little prickly horrible bits.
We already have planned a little cob extension on the front of this structure (south side) and we will be loading that up with glass and windows to let in light. We'll be making a thermal-mass floor for the entire building. Because of the cob section (its look and feel) I would really like to extend the earthy, rounded, smooth feeling to the rest of the building's interior, so I thought that maybe a slipstraw infill between the studs, and then plastered, might work. But by many accounts, slipstraw doesn't have a very high R-value. I'm also a little worried about moisture moving in the plywood, and the need to put up tar paper on the exterior of the plywood in order to plaster it (cutting off the path vapour, possibly causing condensation?) I would really like to earthen plaster both the interior and exterior walls. Any suggestions (even outside-the-box ones) are greatly appreciated! I've been searching and searching for a solution to this, but I think a discussion might be what I need most. Cheers!