Hi Julie. Iam not a cordwood expert by any means but iam familiar with their pros and cons. Is the intended building for living or something else?
Cedar seems like a natural choice due to its rot resistance. It might however be more prone to checks and splits which can be a very negative attribute for a building that needs to have heating and cooling.
"If you want to save the environment, build a city worth living in." - Wendell Berry
Location: Northeast Oklahoma
posted 6 years ago
Oklahoma considers Eastern Redcedar an "invasive" species, and I was wondering if using it for cordwood building would be one way to turn that problem into a profit. A lot of my books are in storage right now, but as I recall, Redcedar was not on the list of Rob Roy's preferred woods. However, as you noted it is rot resistant, and, I'm wondering if it would be a suitable local resource in Oklahoma. Curious if anyone has used it. I'd "start small and chunk" and probably build a kids' playhouse or the face on a dugout root cellar first, but if folks have had success with it, I'd would consider it for a permanent dwelling also.
Red cedar is quite a bit more dense than northern white cedar, only about two-thirds of the R-value. So walls must be thicker to get the same insulation quality. Also, red cedar shrinks more than white cedar. It really performs more like a hardwood. Rot is rarely a problem with any species of wood, because of cordwood masonry's unique breathability.
There are several kinds of red cedar, including aromatic red cedar, used in cedar closets to discourage moths in the woolens. Be careful using a lot of this, as the aroma can be overwhelming. One lady I heard of had a sauna built for her out of red cedar boards and she could not use it; at 150+ degrees, you could not breathe in the room. It was not cordwood, but cordwood would not have been any better, maybe worse.
Finally, to conclude on a positive note, I know of an excellent Earthwood type cordwood house in North Carolina built out of red cedar that was brought down on a flatbed from Maine. Beautiful, very successful home, no aroma issues, an unqualified success.