Building has finally Begun! Squaring away a building permit took a lot of time. We also had doubts about building a foundation above the frost line. In the end, Joanie called her engineering friend who is working on stadium projects in Brazil, or China, and asked his opinion. He gave his approval. The final design incorporates 24″ footings and a 12″ center, on top of about a foot of coarse gravel. In between the two layers we installed 6 mil plastic sheeting, to prevent the gravel from wicking moisture from the fresh concrete.
The Frame I built is only 12″ deep, but it was enough to enclose the pour since the ground was only slightly sloped. The frame I reinforced with 90 degree metal supports and wood cross beams. In the end, I don’t think it really needed all that much because we dug the hole quite tight. The form had to be pounded into the ground, meaning that the surrounding soil added support to the frame. (Better than stakes, which are expensive!) The re-bar frame I built outside of the frame and tie-wired it together using a 6″x6″ wire mesh.
The guy I hired to do the pour was very affordable and helpful. He had a special small batch mixing truck which creates the concrete on site. Our pour was just under 2 cubic yards. The cost was just under $300; I saved a full day’s worth of mixing by hand. Joanie and I leveled the pour and then let it sit for a day.
In the morning, I began building up the base. I used some mortar to level the first course of blocks. You’ll notice I used a mix of full and half-sized blocks. This would work fine, except that I am dry stacking them. Because each course has a different number of joints, there is some variation in the total length of some of the sides, since the blocks measure about 1/2″ shy of their nominal size (to allow for mortar joints). In the end, there is no problem, except that it looks a little ratty. In my case, you won’t see this part of the base anyway.
I used two pieces of angle iron to form a lintel across the gap. To keep the blocks level, I had to grind out part of the surface so it would align flush with the angle iron. This was a dusty pain in the ass. Next time, I’ll just pour a concrete custom lintel with re-bar. I am loving working with the concrete! The last step was to pour concrete inside every other core of the blocks to reinforce the whole structure. I also dropped in a 26″ section of re-bar. I left about a half-blocks worth of space at the top of the filled cores because I’m going to pour joints when I pour the hearth, so that it locks into the base.