Types of Stone Wall Footings

Types of Stone Walls

• The type of footing you use will depend on the type of wall you are building. Simple garden walls may not require a footing at all, while larger retaining walls may require a larger footing with built-in reinforcements. The type of footing used depends on the width and height of your wall, as well as the material used to build it and whether it is freestanding or used to hold back soil (a retaining wall). Mortared stone walls are less flexible than dry-laid walls, and may require a more solid foundation to keep them steady over time.

Basic Footing Construction

• Small, ornamental stone walls that are less than 2 feet high need minimal footing. Once you have marked out where you want your wall, dig a small trench (roughly a third of the height of your wall) that is slightly wider than your wall will be. Good drainage is necessary for any in-ground construction, so put 1 to 2 inches of gravel in the bottom of the trench. For a small wall, simply begin placing your stones directly over the gravel to create built-in footing. Larger walls will require concrete or reinforced footing. Once your footing is in place, leave it to settle for a day or so, which will also give concrete footing time to cure before continuing construction.

Concrete and Reinforced Footing

• Larger walls and retaining walls can pose a danger to people if they are not built correctly. This is a project that is only for someone experienced in stonemasonry. Larger stone walls are built in much the same way as smaller ones. The depth of the footing must be no less than 1/3 the height of the wall, and even deeper for heavy-duty retaining walls. Retaining walls should lean slightly inward toward the held-back soil. Large retaining walls will require a concrete footing, possibly with steel reinforcement bars to strengthen the footing and improve stability. The concrete can be poured straight into the footing trench, or premade concrete footing molds with reinforcement bars (rebar) can be used.

Local Regulations and the Frost Line

• When laying the foundation for your stone wall, check the local regulations regarding how deep you must dig your footer. This varies according to location because soil composition may affect the stability of your wall during the winter. Large stone walls and retaining walls will require you to dig below the frost line to keep it stable. If you don't make your footer deep enough, frozen water will push the wall upward or it can lead to ground heave, causing your structure to become unstable or even topple. Ignoring local regulations can lead to heavy fines, and the extra effort is worth not having to rebuild your wall.