How Tall Should a Concrete Footer Be?

Height and Width

• Generally, concrete footings are flush with the ground's surface. Pilings are placed within the footing's matrix, and these timbers and beams form the foundation of a house. Lamp posts and fence posts are seated in the matrix. The matrix holds the posts in place. Some concrete footings, such as those found on elevated homes and at the base of piers, are higher than ground level. More important than a concrete footer's height is it's width. The width of the footer determines how much weight can be distributed on the ground's surface. This is especially important when building on top of expansive, porous soils.

Soil-Bearing Capacity

• Soil-bearing capacity isn't significant when using concrete footers to support posts. It should be taken into account for building foundations and retaining walls. Overall, the less capable a soil is of holding weight, the wider the concrete footer should be. The actual width depends on soil type and the overall weight of the supportive structure. A one-story brick home built on top of weak soil should rest on footers that measure at least 22 inches wide. The actual configuration and spacing is best determined by an architect and construction team.

Walls

• Concrete footers are also found at the base of retaining walls. Installing these footers yourself is a moderately difficult task involving digging and setting concrete. Determine the width and height of the footers by choosing the wall's style and purpose. Gardeners interested in building raised beds should construct footers that are 6 to 12 inches high and 16 to 18 inches wide. Dig a 6- to 12-inch-deep trench and pour concrete into the excavated area. Smooth the surface and allow the concrete to cure. Top the cured slab with mortar and begin building a brick and mortar wall using the concrete footer as the base.

Considerations

• Most concrete footers are approximately 12 inches deep. Posts and retaining wall footers fall into this category. Still, if walls are higher than 4 feet or if retaining walls are meant to hold back large, saturated slopes, the footers should be wider and deeper. These dimensions should be determined by professional builders.