It started out at the end of 2012 at Rhiannon Permaculture farm, with a concrete pit that was designed to be used as a biogas tank. The pit measured about 4m length by 1.5m width. We were tasked with building an earthbag house to surround and make use of the pit.
We decided to build using sandbags, with a wooden timber frame house on top of these. The sandbags were to form a basement area that included the concrete pit as a sub-basement within the basement. I ran the project almost to its completion, with the able assistance and enthusiasm of many a volunteer.
1. Repair the Pit.
The pit needed to be repaired because the concrete was very poorly finished on the top. It was uneven along its length, narrowed in finish towards the top, and was not level from end to end. We built a mould into which we could put the concrete and fixed it all around the top of the pit for pouring, hand-mixed. We did this over the course of three or four days, mixing the cement and filling some of the worst holes in the concrete walls.
When we took the moulds off, the finish was not perfect but it was much better than what was there before. We now had a reasonably rectangle, level, and mostly smooth pit top to work with that provided a solid base around which we could begin construction of the basement. We ordered a truckload of gravel which was delivered to us the next day.
2. Laying the Foundations of the House
We carted in the gravel and poured it to about six inches height as the first layer for the foundation.
We laid bags filled with gravel for the first part of the foundation. The rest of the house was to be built on these.
We then put in the vapour layers, to prevent moisture and gases from seeping up from the earth below. We mainly re-used stuff lying about Rhiannon, scavenged from a slow death on the ground.
3. Waterproofing the Concrete Pit With Limewash
We used limewash paint (water plus lime – very inexpensive) to waterproof the inside of the concrete pit, up to the point at which we expected the wooden floor in the concrete pit to begin.
4. Wooden floor Foundations
We had to do lots of work on the wood, including sanding, cutting edges to allow it fit together, and painting with Maderol protector. We used thick Eucalyptus wooden beams, coated in Asphaltico blackness on for the floor base. The Asphaltico would protect longer term against any dampness.
Asphaltico is nasty stuff mind you. I was definitely a bit high from that stuff one day. Probably that and the Maderol.
We laid all the wood down over the space of two days. It was a long process, but our finished floor looked pretty decent at the end of it!
We made lots of window and door frames.