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Cement Stabilized Cob

 
Posts: 53
Location: Conroe, Tx
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Hi everyone. I'm still new to all of this and have some questions. I'm planning on buying some books very soon and have quite the list.

I was curious if anyone has tried to add cement to their cob when mixing. If they have were there any advantages/disadvantages? Also, I read something about how you shouldn't add rebar or steel as reinforcement as it makes the cob walls crumble somehow. Is there any way around this?

Thanks for the help. I really appreciate it.
 
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Ok, I am not an expert but I have worked alot with mud, both stabalized and just plain old mud.

Cement, either portland or s type, works best with sand base and will work to an extent with silt base mediums. Clay base or dominant mediums don't do well with lime and portland based stabalizers because they crumble.

Cob is stabalized best with manure or maybe something natural like prickly pear sap or, even blood or some such thing would work.

You don't really need stabaliztion of cob it is plenty durable without stabalization. the outer skin might need a coat or two to protect it but the dried mud and straw of cob is real sturdy stuff.
 
                            
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What do you coat cob with?

Jim
 
Posts: 66
Location: Spokane and near Diamond Lake, WA
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I haven't tried adding cement to cob, but it seems like it would negate two of cob's advantages: 1) You can work it for hours with bare hands and feet and your skin won't be damaged. 2) If you make a mistake, even after the cob hardens you can still soften it with water.
 
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