What type and size of wood should I use to make a form for concrete?
Normally, you'd want to use any type of straight 2&quot;x 8&quot; planks. Why 8&quot; instead of 6&quot;? Because the 6&quot; is really about 5.5&quot; and if plans call for 6&quot; slab, the 6&quot; planks would be too small. You'll have to trench a little to get the planks down to 6&quot; above grade. You'll want to get some rebar and drive it in every 3 feet or so to strengthen the frame. You'll also need steel mesh or rebar under the concrete for strength and to prevent cracking. Depending on who's doing the work, you might want to break it down to smaller pours instead of one large one which would be about 5.3 cu yards.
Depending on what's available in your area, you might be able to rent the forms from a large home store.