(2) Pouring the Footing for a Block Wall
- Every block wall - regardless of height or length - should be placed on a secure footing of poured concrete (Fig. 2). A block barbecue grill or outdoor fireplace requires a large concrete pad as a footing.
- The footing should always be poured deep enough so that the base is below the frost line.
- Always make the footing at least twice as deep as the thickness of the wall and twice as wide (Fig.2). For example, if you are using 8" blocks, the footing should be at least 16" deep and about 16" wide. This footing will provide a 4" rim on each side of the block when laid.
- The form for such footings can be made from rough 2 x 4's, held in place by wooden stakes driven into the ground about every 3' to 4' (Fig. 2)
- For a footing poured in an area where drainage is a problem, lay a drain line along the outer edge of the form (Fig. 2.). Allow for a drop of about 1" for each 20' of drain line. Backfill over the drain line with about 12" of crushed stone or gravel.
- Before you pour the footing, be sure it will not prevent the natural run-off of water an will not divert the flow of water onto any neighboring property.
- If gas, electric, or water supply lines must pass through the footing, you must make an opening. Do this by nailing together four pieces of 2 x 8 and laying them in the proper position before the footing is poured. In many cases, a 4" piece of drain tile will serve the same purpose. Mark the depth and location of the utility opening on your foundation plan or with a stake so you can find it easily later on.
- For large concrete foundation jobs that cannot be finished with one pouring, divide the forms into sections you can handle. Complete one before proceeding to the next.
- Make sure your footing is level by placing a level across the footing about every 8'. Adjust the height of the 2 x 4's by raising or lowering the stakes to make the 2 x 4's level on each side at all points around the footing.
- Fill the form to the top edge, then level the freshly poured concrete by pulling a 2 x 4 or some other straightedge along the top of the form (Fig. 3).
- Work the straightedge back and forth - in a sawing motion - until the concrete is level. Fill in any low spots with additional concrete. Wipe away surplus concrete in the high spots.
- Allow ample time for the concrete to dry fully. If the footing is to carry an extremely heavy load, drying may require up to three days.