[Cob] strawbale, geodesic domes, and igloos

[GlobalCirclenet]

It's hard to see how cob-covered straw is "Just like a purely cob home".
Unfortunately that link to Plasters & Strawbale at
http://www.webace.com.au/~agstraw/cedar.html just doesn't support sealing
strawbale with cob. It's clearly about thin coats of plaster, not cob at
all. It recommends earthen plasters. The difference is significant because
cob is not the same as earthen or any other kind of plaster. Plaster is
applied in very thin coats, esp the first coat to "key" into the straw.  

True, it's inevitable for SOME moisture to get in. But, as the article
shows, professional builders use thin coats of plaster that loses its
moisture to the outside quickly enough that there is no chance of mildew
and mold inside the strawbale. They do not use cob. I doubt they could
afford the contractor liability. Most likely because cob has to be much
thicker than plaster, and takes longer to dry, and releases too much
moisture into the straw.

Plain cob is a safer and much more interesting material.  Sealing straw
properly against moisture means paying professionals for a lot of labor
plastering. You simply cannot risk health problems later by experimenting
or learning on the job. It is not for first time do it yourselfers. Whoever
said strawbale was fast, easy, or cheap forgot about the horrendous job of
plastering completely. 

paul at largocreekfarms.com
http://medicinehill.net
*********** REPLY SEPARATOR  ***********

On 7/22/2004 at 1:21 PM Dognyard wrote:

>GlobalCirclenet wrote:
>> 
>> Which raises the inevitable question: how on earth would you keep
>moisture
>> out of the strawbales when you plaster it with cob inside and out?
>
>You don't. You let it breath. Just like a purely cob home. It's
>inevitable that moisture gets in. You just have to let it get back out
>again.
>
>Try this link for an explaination.
>
>http://www.webace.com.au/~agstraw/cedar.html
>
>Karen in Alberta
>
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