Cob: RE: Sealing cement roofs

[Mike Swink]

A lot of time when somone wanted a void in concrete they could pour half of
thier concrete and and then put strips of polystrene on top of the fresh
poured concrete which is still drying,and then pour rest of concrete over
the strene. When it is set up they would either use pressure steam-gasoline
or paint thinner to melt it. It melts at around 100degrees or so. I thought
of useing strene foam in cob walls and use steam to remove it. To allow
later pipes and vents to be used in voids left from the foam.

In crafts people take the type of plastic which is found in egg crates and
melt them. This left over clear stuff is then used to seal over paint or
paper which was glued to boards. Not sure if the strofoam would have some
simlair after use.

-------This below is my speculation and not to be the basis of changing the
way we build. but reather a question to people that might have better
understanding to speak upt-------

In germany there was a problem with one solid wall that would allow the temp
outside when very cold and inside very warm would set up moisture and freeze
causeing the wall to crack.

A home built in 1840s I visited here in Georgia usa seemed to have a void
between outside and inside. I could only feel the void from the attic. It
might not been two walls. But if there was voids at intervales it could help
the inside wall to be more thermal and the void might help . But this is
just based upon speculation and not proven Unless someone from europe could
tell us. The orginal house in germany was built in 1600's so it might have
been diffrent. When a car once hit the wall and the white wash chipped away
. I could seen huge x cross beams of wood and then enbetween were twigs
crisscrossing with cob infill.