How to Build a Block Wall Footer

Block walls need foundations for structural support.

Footers are a key part of a block wall structure, because they help support the weight of the wall and keep it from sinking into the soil. If a wall didn’t have a footer, it would slice through the dirt like a knife through warm butter, but a footer spreads the load out so that it rests on top of the soil and doesn’t sink. Footers are created from concrete and range in thickness and width based on the needs of the wall. Once set up, they last a lifetime and support whatever wall they are built under.

Things You'll Need

• Work gloves
• Safety glasses
• Dust mask
• Tape measure
• Pencil
• Form boards
• Nails
• Hammer
• Circular saw
• Wheelbarrow
• Shovel
• Concrete mix

Instructions

1. Determine the height of your wall and use that measurement to figure your footing width. The basic rule of thumb is that your footer should be as wide as half the height of the wall. So, if your wall is 10 feet high, you need to have a footer that is at least 5 feet wide. It should also be anywhere from 4 to 30 inches thick, depending on if you are building a cosmetic wall or a foundation wall.

2. Dig a trench for the footer. Use a tape measure to ensure that you are digging down sufficiently deep and wide for the footer. Include width for the form boards. Cut the boards down to size with the circular saw. Measure and mark them with a tape measure and pencil. Nail them together with the hammer and nails and place the forms into the footer trench.

3. Mix up a batch of concrete mix in your wheelbarrow. Shovel the mixture around for several minutes to achieve the proper consistency, according to the instructions on the bag. Dump the wheelbarrow into the form boards and fill them, according to the depth for your specific wall. Repeat the process as necessary until you have enough concrete in the boards. Let the footer dry for 72 hours, remove the boards and build your wall.

Tips & Warnings

• If you are building a large wall, you will want to contract a local concrete company to deliver concrete to your house with a truck rather than try to mix it by hand. Also, hire an excavator to remove large amounts of dirt and rock if you are working on a large project.

• Hire a structural engineer to help you determine the proper footing width and depth for anything other than cosmetic walls. Always wear safety gear when working on home projects.

Resources

• Quikrete: Footers for Walls
• This Old House: Engineering a Retaining Wall
• Ask the Builder: Retaining Walls