A year ago I was approached to see if the Westbury Community Garden would be interested in facilitating the building of an experimental earthbag wall and seat. In June 2011 we started the process with a workshop in earthbag building. This was put on the blog at https://greentasreno.wordpress.com/2011/07/25/earthbag-wall-building/ This was a success, but as the months passed by things stalled.
There were a couple more rows of earthbags added but after checking for stability we decided to remove them,as they had not been tamped sufficiently, and add a couple of new rows. The seat on the outside was stepped up twice to make three different seating heights.
Now in the last couple of months there has been much action and the wall has been rendered with a mud/straw render coat, then a lime plaster coat and now is getting its final limewash coats.
The mud render was made from clay that was spoil from a hole dug for an underground water tank. Sand came from a pile that was left over from the school cricket pitch and chopped straw added. Several test patches were trialled, each with a different ratio. Finally we settled on one clay, three sand, and a good handful of chopped straw.
The first coat we put on filled the voids between the earthbags.
After this we decided that the clay needed screening. An old bed frame with the old fashioned chain link stretcher was purchased from the tip shop for a whole $5. This worked a treat, enabling us to just shovel the clay through the mesh and make a finer render.
After the base coat had dried We decided that the ends of the wall needed attention. There were plenty of old sleepers in the scrap pile in the Community Garden so we used those to create two ends.
Then after the base coat a scratch coat was put on and left to dry thoroughly.
The final coat was a lime/sand plaster mix with handfuls of chaff thrown in as an extra binder. Chris did a great job as a master plasterer and I acted as labourer.
The next stage is to get the local Primary School involved in making some pavers to be mortared to the bench seat on the outside of the wall and to create a bench inside using cob walling techniques and gabions.