from Bread Earth and Fire (The Earth Oven)

 con't The Earth Oven

 

You’ll probably find some coarse gravel at the top of the slab, but if you wait just a little bit until it starts to set up, you should be able to trowel it fairly smooth. Don’t worry if it’s not perfect, ours wasn’t and it didn’t matter because the rocks we used for the base were all irregular, and these sat on top of the slab. After your slab gets hard (concrete dries fast in hot weather), and it might only take a couple of hours, you should hose the top of it because you don’t want the top to dry very much faster than the interior. Instead of hosing the slab, you could cover it with a tarp to slow down the drying process. No matter what you do, the next day you should be able to knock off the wooden form and start building up. Although your slab feels hard to the touch, it really takes at least a week for it to fully harden. It’s okay to work on it now, but be aware that you should not drop heavy items on it or walk along its very edge. Abbott and Nancy chose to build the oven base with rocks because aesthetically it worked for them and to get the rocks we had to take their canoes up a lovely Maine river where we found them in a pile. We were very fortunate indeed, because the rocks were left over from where giant towers supporting high-tension lines were sunk into the ground.When searching for oven materials, if what you find is not on your property, then it probably belongs to someone else. Get permission before you take anything, even if it’s only a stone or a pail full of sand or clay.The rocks we took for our project were irregular, but mostly flat and not heavy. However, it took multiple canoe trips to get all we needed, and then we had to load them into a wheelbarrow to haul uphill. Canoeing was fun, but hauling the rocks uphill wasn’t, as the rocks seemed to become heavier and heavier.Yes, there are easier ways to get rocks. You might consider going to Big Box to buy them. Some companies that do landscaping will deliver them to your building site, but you must pay for this service. Nevertheless, you might think it’s a great deal (especially after you’ve done the hauling yourself), but shop around. Nobody says you have to use rocks for your base. In fact, building a rock base will take longer than building your oven proper. An alternative would be cement blocks. They are cheap, functional and easy to use. If you don’t like the industrial look, you can stucco the blocks, add a colorant or paint them. If you decide on a block base, then it’s easier to make a square rather than round base, but you can buy curved blocks if you really want a round base.  If you choose to have a square base, the oven can still be round. Obviously, we preferred the rock look.Find the center point of the slab, and with a string and felt tip pen, draw the biggest circle you can and that should give you a diameter of 48”. The circle defines the outer perimeter of your rocks. In retrospect, however, had we centered the rocks over the drawn circle, we would have had more room inside the base for insulation and the top slab. I recommend centering the rocks over the circle. Of course you could have made the slab bigger, but that would have been more work. to be con't