wow. you never see folks admitting mistakes like this. I would've thought cob would be excellent at keeping you warm, once you warm it up. I wonder what he plans on doing now.Reluctant Watchman wrote: ↑April 30th, 2023, 7:48 am I found the experience of this man in building a cob home in northeastern Missouri to be enlightening. If you live in a cold climate, you need insulation. Straight cob construction is not ideal in cold climates:
https://theyearofmud.com/2011/03/03/cob ... d-climate/
Did he not use a vapor barrier? that's what it's for - it stops moisture from condensing, which would be a big problem in a humid climate like MO.
And could you not use foam as part of the barrier? EPS foam covered with mud seems like it would be a pretty efficient home.
Seems like cob is well adapted to desert living - where you want to keep cool during the heat of the day. It would be good for that, I would think. If it tends towards equilibrium, then at night when it is cool, the thing would cool down. Then during the hot day, it would stay cool for most of the day, until evening, and then retain that heat overnight. What do you think?
Straw bale is appealing in this situation - the straw would have excellent thermal properties.
FWIW, the local utility co. did an efficiency study using my plans for a log home - R15 is the minimum requirement for exterior walls around here. Since a typical pine log has r-values of 1.5 per inch, this means an 8" log = R12 (8*1.5=12). My logs average 17", so they have an r-value of about R25. When the outside was completely chinked, I noticed some improvements in the inside temperatures - they were more stable. Even on a hot day when it's 90+ with 80% humidity, the inside stays a lot drier and cooler - basically follows whatever the low was for the night before (that's the thermal mass working). At any rate, they calculated that my log home will be at least 1/3 more efficient than a standard framed home.
Not all log cabins are the same - the biggest logs I've seen for kit homes are 8". They get around the r-value issue (r12, but r15 is required) by adding some closed-cell foam in between the logs. But I've heard from a lot of folks with kit homes in the north who say they are always cold in the winter - they can't get the wood stove hot enough to overcome the chill in the air inside.
This winter when we had 3 days of -5 for the high (extremely rare here in the South), The best I could do with my little parlor stove was to get the inside up to about 38 degrees. Granted, the poor stove was trying to heat about 40,000 cubic feet of air and 300 tons of logs, so I would never expect it to get the temps into the 70's with the thing not completely insulated - the gable ends are not insulated at all at this point - they are 40' x 10' triangles, so I'm losing a lot of heat through them. What I AM curious about is how it will fare when I get the HVAC unit hooked up - At the first cold snap we get, I expect the HVAC unit to have to work hard to get the temp regulated, but then once it reaches equilibrium, I think it will require minimal use.
Still, reports from others are encouraging: my friends in WA state had that summer of 115 days for a few weeks, with no AC in their log home, and they said it never breached 80 inside.
it sounds like you should build with what's available in your area. lots of trees= build with logs. lots of sand/clay = build with adobe/cob. lots of straw = strawbale.