Has anyone built any cob structures in Idaho? We are looking to purchase land there and build a cob house. I have heard mixed reviews on cob in cold/hot weather with condensation or cracking...Does anyone have insight to this?
I have not gotten around to writing a "focus article" on cob as of yet to send new members to, but is in the works. In the interim please do a search for past discussions and read the plethora of info that you can find here. Then perhaps you can ask more specific questions about a building site once you secure it. The land itself will tell you much about what should/could be built upon it. Good luck, and again welcome and thank you for joining the community, we will all learn much together.
posted 6 years ago
Thank you for the warm welcome Jay!
I appreciate the direction, this site is a gold mind. THANK YOU.
Hello, I do historic restoration work in No. Utah and SE Idaho and I have restored; several turn of the century adobe(plus I live in one), a 140 year old pise(rammed earth) and consulted on a tuff block construction restoration. These buildings are built in a very similar fashion to cob, but cob seems to not have been very popular in this area and no, I don't know of anyone in my area that is building with earth.
HI Brittany, sorry for the super outdated reply. You can definitely do cob building in Idaho, although I recommend you consider a cob/strawbale hybrid with the bales being your northern insulation. I live in Western Montana so have basically the same climate and am building a cob home (www.montanacobcottage.blogspot.com). If you are not set on building cob, definitely look into strawbale instead as the insulation is superior and you can still have a wonderfully natural and toxic free home.
It might be more mild but its still in building zone 5 which is pretty cold. The 2012 International Energy Code minimum for mass walls (Cob) in zone 5 is R13. Depending on what R per inch you give cob, probably in the .25-.5 range, your cob wall would need to be 52" - 26" thick to meet the intended poorest performance allowed by law. You could always take the performance path to compliance which would probably mean super high levels of floor, attic and window R values to make up for the crummy performance of typical thickness cob walls.
Strawbale easily exceeds the wood framed wall construction Rvalue minimums in zone 5. I think the wood frame minimums will result a much more comfortable and affordable to condition home, in terms of wall performance, in my opinion.
"If you want to save the environment, build a city worth living in." - Wendell Berry
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