Building a test wall at Plymouth
Fig.1 The frame for the wall was designed using 3D software
It was decided to build the test with half scale, with two equal layers of cob at 200mm each. The two layers will be sealed between steel mesh.
Fig. 2 Structural cob mixed the traditional way
The structural layer was mixed using the traditional method of mixing sub-soil, fiber and water on the ground using feet. The mix is optimally mixed, and is made from UK6 soil, with 2.5% hemp straw.
Fig.3 The insulating cob was mixed mechanically
The insulating cob, which was made from UK3 soil with 50% hemp shiv, was mixed in a ‘Baron’ forced action mixer.
Fig.4 The different mixes of cob are built in layers
A form is used to keep the two layers of the right dimensions, and also adds an angle to each lift, creating a ‘saw tooth’ bond between the layers.
A layer of hemp fiber is placed across the layers.
Fig.5 Finished wall still in shuttering
Fig.6 Completed wall on mobile plinth
When the shuttering has been removed, the wallet has been pleasing texture from the steel mesh. It is also straight and true, with little further finishing to be done.
Fig.7 Squeezing the wall into a lift.
Fig.8 The wall forming a centerpiece at the Wash-up event
Due to the fact that the service was lifted out of action, it was a bit of a success at the Levinsky Building at Plymouth University.
This article is available at: http://www.youtube.com/watch?v=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. For some of our stakeholders, builders and architects, this is their first view of a ‘CobBauge’, and what is ahead in phase two of this project.