Cob: Bentonite
dcv
dcv at datawise.net
Sun Jan 19 11:13:45 CST 2003
Having worked in excavating for several years, on occasion we would work in pond and lagoon construction. It was common to "patch" with Bentonite due to the fact that the pipe and other water tubing was often laid in place after the excavating was finished. Event though we were required to place and tamp adequate clay in place for water retention, some leakage would occur around the areas were the piping was installed.
Although you should always follow the directions on the product bags, we double dosed the area and rototilled it to a depth of 12" in around the area - we never had any problems with additional "leaks" afterward. Once this material comes into contact with water it is expands to something like 100 times its dry mass and coagulates or gels with the soil.
Just some info for your planning efforts.
dcv
----- Original Message -----
From: Mike Swink
To: stefanson ; Coblist
Sent: Saturday, January 18, 2003 2:08 PM
Subject: Cob: Re: Underground Cob
I was taught in school that the hyrdostatic pressure which pushes over walls etc. Is the chief concern in underground shelters.
What ever you can do to provide adaquate drainage around your structure is a good thing.
Note this type of water travels several feet underground and is not the water which is on the surface. Small streams which you see gving water to dug wells is also the same way.
Most people forget that overtime the earth changes around a home with settlement of organic material [leaves,dirt,etc]. Can build up to the point it covers drainage pipes and thus defeats thier purposes without being mindfull such things need to be done on regular baisis. One home the water meter had to be raised up,to stay on top of surface four times. .
I liked the links to the method of waterproofing of the ancient times. Gley which is simply manure ,straw and clay once drys out acts as membrane that expands when moisture comes into contact with it like Bentonite Waterproofing[http://home.cogeco.ca/~nhemm/waterproofing/bentonite.html] Note with the gley it requires more than What I said to work so do your home work. Even with Bentonite and Electro Osmois they still use gravel and sometimes even do things to prevent surface water.
I do not know if it is the bias that I have been taught which gives me alarms some one would build a cob underground structure.
If the house was built up into a ridge then most water would never be a problem. Some people need to view thier land from a plane to see how water flows. Driving in a car does not show the lay of the land. When a water main burst open it was so unexpected that peoples homes had a lot of damage from a unseen source of water that was underground. It was the strange sinking areas of the yards that prompt people something was going on. One house had a better drainage system and was not effected.
One unrelated thought about water drainage is that of Thomas Jefferson's Home. He built it to last. He did not have gutters but he did brick lined a dug ditch around his home.
In germany to overcome water problems due to snow melting when it was 5ft deep or so. Was to cover areas around the house with cobble stone and thus the water melted and then flowed into cisterns or streams. THe rain and water never underminded these homes like some we see here in the USA.
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<DIV><FONT face=Arial size=2>Having worked in excavating for several years, on
occasion we would work in pond and lagoon construction. It was common to "patch"
with Bentonite due to the fact that the pipe and other water tubing was often
laid in place after the excavating was finished. Event though we were required
to place and tamp adequate clay in place for water retention, some leakage would
occur around the areas were the piping was installed. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Although you should always follow the directions on
the product bags, we double dosed the area and rototilled it to a depth of 12"
in around the area - we never had any problems with additional "leaks"
afterward. Once this material comes into contact with water it is expands
to something like 100 times its dry mass and coagulates or gels with the
soil.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Just some info for your planning
efforts.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>dcv</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=mswink77 at mindspring.com href="mailto:mswink77 at mindspring.com">Mike
Swink</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=stefanson at sbcglobal.net
href="mailto:stefanson at sbcglobal.net">stefanson</A> ; <A
title=coblist at deatech.com href="mailto:coblist at deatech.com">Coblist</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, January 18, 2003 2:08
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Cob: Re: Underground Cob</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>I was taught in school that the hyrdostatic
pressure which pushes over walls etc. Is the chief concern in underground
shelters.</FONT></DIV>
<DIV><FONT face=Arial size=2>What ever you can do to provide adaquate drainage
around your structure is a good thing.</FONT></DIV>
<DIV><FONT face=Arial size=2> Note this type of water travels several
feet underground and is not the water which is on the surface. Small streams
which you see gving water to dug wells is also the same way.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Most people forget that overtime the earth
changes around a home with settlement of organic material [leaves,dirt,etc].
Can build up to the point it covers drainage pipes and thus defeats thier
purposes without being mindfull such things need to be done on regular baisis.
One home the water meter had to be raised up,to stay on top of surface
four times. .</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I liked the links to the method of waterproofing
of the ancient times. Gley which is simply manure ,straw and clay once drys
out acts as membrane that expands when moisture comes into contact with it
like <FONT face="Times New Roman">Bentonite
Waterproofing</FONT>[http://home.cogeco.ca/~nhemm/waterproofing/bentonite.html]
Note with the gley it requires more than What I said to work so do your home
work. Even with Bentonite and Electro Osmois they still use gravel and
sometimes even do things to prevent surface water.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I do not know if it is the bias that I have been
taught which gives me alarms some one would build a cob underground
structure.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If the house was built up into a ridge then most
water would never be a problem. Some people need to view thier land from a
plane to see how water flows. Driving in a car does not show the lay of the
land. When a water main burst open it was so unexpected that peoples homes had
a lot of damage from a unseen source of water that was underground. It was the
strange sinking areas of the yards that prompt people something was going on.
One house had a better drainage system and was not effected.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>One unrelated thought about water drainage is
that of Thomas Jefferson's Home. He built it to last. He did not have gutters
but he did brick lined a dug ditch around his home.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>In germany to overcome water problems due to snow
melting when it was 5ft deep or so. Was to cover areas around the house with
cobble stone and thus the water melted and then flowed into cisterns or
streams. THe rain and water never underminded these homes like some we see
here in the USA.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV></BLOCKQUOTE></BODY></HTML>