I poured the hearth slab today. The form measured about 70 inches by 83 inches. There’s going to be plenty of room in this oven.
Here’s what I learned:
1. I really stink at concrete work. (lifting, mixing shoveling, pouring, smoothing, filling block cores, etc. is too much for one person at one time!)
2. The little rental mixers from Home Depot work best with about one bag of concrete.
3. There’s a fine line between not enough water, just right, and too much.
4. Thank goodness nobody will see the hearth slab. I tried to float it out and make it nice and smooth, but the aggregate is exposed in many places.
5. You can’t screed a four-inch slab when you use 8 inch forms! I put hunks of 2×4 at the corners to get close, then pulled them and filled the voids.
6. I’m glad I wore a dust mask and gloves.