[permaculture] Question about Earth Homes, thermal mass and humidity

Keith D Johnson keithdj at mindspring.com
Sun Jan 31 13:29:54 EST 2010

I have built and worked on cob, clay-straw, strawbale, and adobe in the SE, WNC. My favorite is clay-straw. All that I worked on (or observed) use a rubble trench with stone, urbanite, or concrete foundations and wide overhanging roofs.

Generally the foundation was installed, followed by framing, next the roof and finally the infill. Clay-straw has the advantage that when the seeds in the straw (there are always some and fresher is better) germinates it pulls the moisture out of the walls and when the grass dies it provides extra anchoring for plasters.

If you want to learn more and get your hands on some projects, go to Earthaven Ecovillage near Black Mountain / Asheville.

My general recommendation is to minimize strawbale and cordwood or use them on dryer upper stories.

I know what you mean about mold. We used to have it growing on glass and ceramic. Glad we live in Indiana now, where, although it's still humid, is not nearly as intense as further south. Our clay-straw house at Earthaven was one of the most mold-free there. Build on a breezy ridge if you can and avoid the valleys.


-----Original Message-----
>From: Udan Farm <udanfarm at yahoo.com>
>Sent: Jan 31, 2010 12:15 PM
>To: permaculture at lists.ibiblio.org
>Subject: [permaculture] Question about Earth Homes, thermal mass and humidity
>HI Folks,
>Reading about Quail Springs and their buildings, (I've been there by the way, and it's really a great example of permaculture in dry climate) I've been wondering if ANYONE knows ANYONE who has previously already BUILT any kind of earth homes-cob, in-ground, earthship, cordwood, etc. homes in the SOUTH...I'm talking HOT, HUMID, buggy, HUMID southern USA?
>I ask because a lot of folks are looking to me and my husband, as permaculture teachers, asking questions about building something from earth that doesn't cost 200k, and I'm of the mind that those big thermal mass things connected to the ground DO NOT work well in the humidity. It gets cold and hot here, sometimes with about a 40* range in one day, add the humidity and the walls (even on a well insulated stick built house) SWEAT something aweful, and books, rugs, fabrics, clothes and shoes go quite moldy.
>I'm fond of the Cracker style house-up off the ground, wide porches, lots of windows, high ceilings, and a cupola on top that opens.That works for FL and central GA but even up into the mountains, the ONE building I know of that's about 7 years old-made of cob and sitting on the ground is MOLDY smelling the minute you walk in it. And I know everyone knows that the answer is not HVAC running 24/7/52...
>I would love to hear you thoughts on that subject and if you know anyone with an older thermal mass/earth house I could ask these questions of...
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