Building Forms for Poured Walls

Forms for poured walls must be stronger than those for most other concrete projects. This is because they must contend with two substantial forces: the weight of the material itself and the hydrostatic pressure created as wet concrete pours into the wall.

If you mix your own concrete, you can pour it into the form slowly and use somewhat less massive forms. But for ready-mix concrete poured directly down the chute of a truck, use 3/4-inch plywood backed by 2x4 studs at least every 24 inches.