Cob: RE: Posts embedded in cob

Wed Nov 1 12:19:25 CST 2000

Hi Shawn and Robynn,

The cob as it shrinks/dies will separate from the embedded posts. Which
might not be a problem if the wall is quite thick surrounding the posts. If
the cob is thin around the post it will crack. Also since you intend to have
straight walls with the post in the corners the wall will be weak in the
corners. The strength of cob would be compromised in that design. Not a good
idea in an earthquake zone. Note that straight walls are considerably weaker
than curved walls. One of the things I love about cob is the organic curved
walls.

Some options you might want to consider:

Make the cob loadbearing, build temporary posts holding the roof then build
the cob walls put a top plate on and lower the roof onto the cob. Curve the
corners for greater strength.

Leichlehmbau (often refered to as light clay or straw-clay). Using your
current ideas make temporary forms for the walls and pack straw dipped into
a clay slip into the forms, once the walls have hardened remove the forms
and plaster both sides of the wall with cob plasters. The advantages of this
technique are much improved insulation value, faster construction time &
lighter walls. You can put lots of cob on the inside of the wall to provide
mass.

Load bearing or modified post and beam strawbale construction can easily
give straight walls and strong corners.

Regards,
Will

-----Original Message-----
From: Shawn Honeychurch [mailto:ironfire at cyberlink.bc.ca]
Sent: Tuesday, October 31, 2000 7:06 AM
To: coblist at deatech.com
Subject: Cob: Posts embedded in cob

Hi All;

We are planning to build a post and beam style house with cob walls.  We are
going to build short sections of straight cobs walls between the posts using
forms and shape the cob around the posts so that the finished house will not
have any posts showing.  We were just reading in the "Cob Builders Handbook"
that this is not suggested due to the shrinkage of the cob while it is
drying.
Has anyone tried this, or does anyone have suggestions on how to get around
this problem so we don't have to totally redesign the house?

Shawn and Robynn

-------------- next part --------------
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2650.12">
<TITLE>RE: Posts embedded in cob</TITLE>
</HEAD>
<BODY>

<P><FONT SIZE=2>Hi Shawn and Robynn,</FONT>
</P>

The cob as it shrinks/dies will separate from the embedded posts. Which might not be a problem if the wall is quite thick surrounding the posts. If the cob is thin around the post it will crack. Also since you intend to have straight walls with the post in the corners the wall will be weak in the corners. The strength of cob would be compromised in that design. Not a good idea in an earthquake zone. Note that straight walls are considerably weaker than curved walls. One of the things I love about cob is the organic curved walls.

<P><FONT SIZE=2>Some options you might want to consider:</FONT>
</P>

Make the cob loadbearing, build temporary posts holding the roof then build the cob walls put a top plate on and lower the roof onto the cob. Curve the corners for greater strength.

Leichlehmbau (often refered to as light clay or straw-clay). Using your current ideas make temporary forms for the walls and pack straw dipped into a clay slip into the forms, once the walls have hardened remove the forms and plaster both sides of the wall with cob plasters. The advantages of this technique are much improved insulation value, faster construction time & lighter walls. You can put lots of cob on the inside of the wall to provide mass.

<P><FONT SIZE=2>Load bearing or modified post and beam strawbale construction can easily give straight walls and strong corners.</FONT>
</P>

<P><FONT SIZE=2>Regards,</FONT>
<BR><FONT SIZE=2>Will</FONT>
</P>
<BR>
<BR>
<BR>

<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: Shawn Honeychurch [<A HREF="mailto:ironfire at cyberlink.bc.ca">mailto:ironfire at cyberlink.bc.ca</A>]</FONT>
<BR><FONT SIZE=2>Sent: Tuesday, October 31, 2000 7:06 AM</FONT>
<BR><FONT SIZE=2>To: coblist at deatech.com</FONT>
<BR><FONT SIZE=2>Subject: Cob: Posts embedded in cob</FONT>
</P>
<BR>

<P><FONT SIZE=2>Hi All;</FONT>
</P>

<P><FONT SIZE=2>We are planning to build a post and beam style house with cob walls.  We are</FONT>
<BR><FONT SIZE=2>going to build short sections of straight cobs walls between the posts using</FONT>
<BR><FONT SIZE=2>forms and shape the cob around the posts so that the finished house will not</FONT>
<BR><FONT SIZE=2>have any posts showing.  We were just reading in the "Cob Builders Handbook"</FONT>
<BR><FONT SIZE=2>that this is not suggested due to the shrinkage of the cob while it is</FONT>
<BR><FONT SIZE=2>drying.</FONT>
<BR><FONT SIZE=2>Has anyone tried this, or does anyone have suggestions on how to get around</FONT>
<BR><FONT SIZE=2>this problem so we don't have to totally redesign the house?</FONT>
</P>

<P><FONT SIZE=2>Shawn and Robynn</FONT>
</P>

</BODY>
</HTML>

Rethink Your Life! Finance, health, lifestyle, environment, philosophy	The Work of Art and The Art of Work Kiko Denzer on Art