Wood-cob/bale-cob

Cob house in one day!

 

In 2014, we wanted to see if we could built a cob cabin in one day. 60 people showed up to help, some of them cooks, some carpenters. In order to make the cob go up fast, we used the "wood-cob" technique. This also made it so the walls needed very little trimming and there was no "muffining": the way wet cob walls tend to bulge out on the top because it is too wet and heavy.

Bale-cob

 

Bale-cob is used in places where you want extra insulation and at the same time have the wall go up a little faster. Its is usually on the north or west side of cob buildings, where there few or no windows

First layer of bales goes on the 10 inch cob wall. The bale is flush on one side and a little bit inset on the side you see in this picture. This can easily be fixed with a straw-clay plaster. The wire will be installed in between the bales.
In this wall, the bales are "on edge". Putting slip on the bales happens on the wall. If you do in on the ground the bales can get too heavy to lift.
Make sure that the bale wall goes up plumb. Before the seams are stuffed with cob, the wall tends to move easily. Keep an eye out for that!
Once the wall is plumb, start gently filling the seams with cob. Having people work on both sides of the wall will make it easier to keep the wall plumb.
The sides of the bales are best slipped after the cob is in and has dried. Once the slip is on, you can start applying the straw-clay plaster.
This is a slightly rounded bale-cob wall. This is a little risky! The cob column in the middle gives it some extra stability.
Notice the generous amount of cob on top of the last layer of bales. His will help compress the wall and provides enough cob for the roof rafters to be anchored into.
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Make sure that the bale wall goes up plumb. Before the seams are stuffed with cob, the wall tends to move easily. Keep an eye out for that!