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Concrete slab vs cobb floor.  RSS feed

 
Sean Rauch
Posts: 136
Location: Winnipeg, Manitoba
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I'm researching options for our house build and am interested in the idea of cobb vs concrete. We will have a highly insulated slab on grade main floor with no basement. I'm pretty sure we can't use cobb for the grade beams but the slab may be an option.

Here are my requirements:

EPS probably in the range of R40+ under the slab that will tie into the EPS under the grade and into the house insulation.
Our house will be passive solar based with as much mass as possible so the main floor seems like a logical choice.

Concrete has some very nice structural properties and I"m wondering how a cobb stacks up?

Also how does the real world costs and maintenance compare?

 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Sean & Permies Cloud : Get the hard bits out of the way first, goto> cchrc.org this is Cold Climate Housing Research Center. a branch of University of Alaska, Fairbanks.

You and I know Cold, they know COLD ! they build houses on 'rafts' of insulation to keep the permafrost from melting and the house sinking into instant swamp!

Regular Portland cement + or concrete is wicking, there for you have to treat it or isolate it from the cob ! See their articles on geopolymer cements !

Passive houses speak of ~2-ish~ Air exchanges per hour, except when we are using our travel Yurt we get by on 0.6-ish A.C.R.s Usually air exchanges are handled buy fans that
move air over a common walled heat exchanger, many with built in heat pump units, again a little research will find you videos to watch about safety guidelines for operation !

C.C.H.R.C.is trying to reduce the number of homes ruined by trapped moisture, and mold mildew and rotting wood, many places in alaska saw their price per gallon of #2 fuel oil
cost $10.00 U.S., cchrc homes operate on winter fuel needs in the 125 -175 gal of home heating fuels ! Again, you can profit from lots of time spent here !

Cob vs concrete, Cob wins every time because of the sweat equity you put in ! Remember #1) insects won't eat it, #2) It will not burn and #3) it is as cheap as dirt !

properly built and sealed off from moisture concrete can also last with less maintenance than Cob which needs skillful construction and a 5 yr maintenance program !

Consider getting a used copy of ' The Hand-Sculpted House 'from Amazon or my favorite Alibris hope this helps, for the good of the Craft !

Think like fire, flow like a gas, Don't be the marshmallow ! As Always, your comments and questions are solicited and Welcome ! PYRO - Logically Big AL !
 
Sean Rauch
Posts: 136
Location: Winnipeg, Manitoba
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I'm trying to compare real cost for cob vs concrete. I know that cob can be near free but time is in fact money and I'm wondering how the real world numbers work out. I guess a better question would be approximately how many man hours per square foot go into cob?
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Sean Rauch & Permies Cloud : Cob is incredibly labor intensive, especially if you do not have people working to make you cob and pitching it up to you while you work
around the perimeter of your building in a steady spiral. Climbing up and down to move cob by hand without helpers would make jesus weep ! Big AL !
 
Sean Rauch
Posts: 136
Location: Winnipeg, Manitoba
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Yea its looking like if I'm gonna use cob its gonna be me hiring someone who knows how to be efficient at it.
 
Brian Knight
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Location: Asheville NC
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The trick is to keep the area very small or have "workshops" where people can come to "learn" about natural techniques.
 
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