How to Cure the Concrete Footing for a Deck

Get the appropriate-sized tube-shaped building form. These forms are typically available in 8-, 10- and 12-inch diameters. The form must be twice the diameter of the post it will be supporting. For example, an 8-inch form is required to support a 4-inch post.

Dig the footing holes 6 inches deeper than your local building codes require with a pair of post hole diggers. Most building departments require that footings reach below the normal frost line. Add 6 inches of gravel to the bottom of the hole to aid with drainage issues.

Cut the tube to the correct length with a handsaw, ideally leaving 2 to 6 inches of the tube above ground to allow for greater drainage. Carefully center the tube in the hole and check to ensure it is level before backfilling around it with the dirt removed from the hole.

Add concrete to the form until it is half filled, then use a shovel to press down on the concrete with a shovel, eliminating any air pockets that may have formed. Continue filling the form until the concrete is even with the top of the form. Drag a steel trowel across the top of the form to level the concrete.

Inset the deck hardware required for your decking project. Although the exact method of attaching the post to the deck footing may vary from project to project, it typically consists of a post anchor and J-bolt combination or an U-shaped beam anchor. Align the decking hardware on the top of the filled form and smooth the surface of the concrete again with a steel trowel.

Allow the forms to remain in place for at least 24 hours for adequate concrete curing. Because the interior of the forms is waxed, moisture cannot escape from the concrete prematurely, promoting maximum strength for the concrete. Failing to use the forms will allow the soil to absorb the moisture from the concrete, resulting in a weaker deck footing.