hello all, I am in the midst of building a concrete slab foundation for my new garage. I have dug out the site, put up my boards, and have dug the trench for my footers around ther perimeter, but what I need to know is how to backfill on the outside of the boards so that the cement will not flow out underneath them. There is a wide gap at the back corner where the ground landscape is very low in comparrison to the other side. I also need to know how much cement to order if the pad itself is going to be 6 inches thick, but i have to account for the cement which will fill the trenches around the perimeter.
If there's a large gap left under the boards, you're not done forming yet. Fill that gap in with more lumber to save on concrete.