We have finally begun work on the root cellar in Anatoly's backyard! Right next to the cob sleeping cottage. We already had a big hole from mining clay for the cob house (the hole was the inspiration for the root cellar, in fact). Here is Mike beginning to persuade the hole into a more defined shape...
This is the drainage "bulb" at the end of the tail trench. This provides an exit path for any water that collects under or around the root cellar. This bulb will be filled with gravel and then covered up with soil. You won't ever see it once the grass takes over, but it will be underground performing very important work. Without drainage, there would be serious water issues inside the root cellar, namely standing water and dampness.
Our client decided that he wanted a poured concrete foundation (versus concrete block, or wooden posts, or other options...), so we began to make forms. You can see in the photo below that we lined up pieces of broken concrete around the perimeter of the pad. These act as a "footing," which spreads out the weight of a heavy concrete foundation, like the one we'll be pouring. The footing is usually poured out of concrete, too, but a neighbor was getting rid of these concrete chunks and so we saw an obvious opportunity for reuse!
Here is the form before bracing.
Rebar hanging in the form. It will provide tensile strength in the concrete, when the concrete dries around it. It's like the straw in cob.
And here is the form all braced and ready to handle the weight of wet concrete!
We ended up designing the form so that we would have a floor system, on which to lay some plywood, so that we could roll our wheelbarrows of concrete up on top of the form, and pour from the middle (instead of having to make dozens of ramps on all sides).
The floor worked great.
Mike trowels the top of the wall, to get it as smooth and level as possible.
Here I am removing the forms with a sledge hammer, the following day. Forms can be difficult to remove, because the weight of the concrete squeezes everything together tightly. But despite having the bash things apart, all of the forms are mostly intact, and ready to be used again for another project.
The finished foundation wall!