How to Build Forms for Concrete-Block Wall Footing

Concrete block walls are sturdy and durable.

Before building a cinder-block wall, pour a concrete footing to support it and prevent seasonal freeze and thaw from shifting the wall. After repeated seasons, even the strongest wall will crumble without a good base. How deep you dig the footing will depend on where you live and local regulations, as it's necessary to dig below the frost line. While poured concrete walls require a form from top to bottom, footings only need a form for the top part of the footing to give it a clean edge.

Things You'll Need

• Flat-edged shovel
• Boards, 2-by-4-inch
• Saw
• Plywood sheet
• Hammer
• Nails, 2-inch
• Stakes

Instructions

1. Dig a ditch for the footings. The minimum width of the footings for a cement block wall is 16 inches, and the minimum depth is 8 inches if you live in an ice-free zone. While you can use a spade for the top portion of the footings, to create a flat bottom that will support the wall evenly, use a flat-edged shovel for the bottom portion of the ditch. A flat-bottomed shovel will also help you dig clean, even sides to the ditch.

2. Dig out a 1 1/2-inch rim on each side of the ditch for the 2-by-4-inch boards. Cut the boards to fit the length of the footings. For the final board on each end, cut the board 1 1/2 inches shorter than required to accommodate the end board. These boards need to sit in the rim level.

3. Cut a 2-by-4-inch board to fit across the ends of the wood forms and hammer a nail through the cross boards into the end of the 2-by-4-inch form boards.

4. Pound a stake on the outside of the form every 4 feet. Nail the form to the stake.

Tips & Warnings

• If the ground is sloped, cut the lower rim level and create a second form using 2-by-4-inch boards for the higher areas, stacking it on top and overlapping the lower form by 1 foot. Cut a 4-by-6-inch piece of plywood, and use this piece to cobble together the upper and lower forms.

• If the stakes aren't enough to hold the form vertical, pound a second stake in next to the first at a 45-degree angle, leaning toward the form, and nail the two stakes together.

• If the ground is too soft and doesn't hold its form, use 2-by-6-inch boards for the form.

• Tie back loose clothing and hair before operating power equipment.

• Wear safety goggles when using power equipment.

• Check with local authorities to see if you have to obtain a permit for your planned project.

References

• "You Can Build Masonry"; Steve Cory; 2010
• Ace Hardware; Laying Concrete Blocks; 2011

Resources

• OSHA: Safeguarding Equipment and Protecting Workers from Amputations