Stonewall Heading South

One concern of any home inspector is water control around foundations or any subterranean wall. The combination of soil and water against a wall can cause hydrostatic pressure that will cause the wall to implode. The main defense is proper water control. Retaining walls much like a foundation wall is a wall that holds soil in its place.

Here is a typical question I receive on this subject.

Question: We just moved into a wonderful cape cod that was built in the 1950's. We love the home, but we have a retaining stonewall on the side of our drive and it appears to be leaning inwards. It looks like there was some patchwork in the past (new concrete). How worried should I be and should I just pay to have a new wall built? Answer: Retaining walls over the years will start to lean inwards because of hydrostatic pressure. This is caused by poor grading on the high side of the wall, and also poor draining at the bottom of the wall. If the wall is leaning in slightly, with proper maintained and drainage the wall can still perform for many more years.
For proper grating at the top of the wall, the dirt should be higher against the wall and sloping down away from the wall. This will help stop water pressure against the wall. You should find drain holes (scuppers) at the bottom base of the wall, removing dirt and debris from these holes will help with drainage. This will also help prevent water pressure against the wall.
Perform these maintenance tips and monitor the wall movement.
If the wall keeps moving, there are other cures besides removing and rebuilding the wall. One such method is to install soil anchors. Soil anchors are rods that go through the wall and under the soil, and are anchored in the soil. There are plates on the open side of the wall that the rods pass through. The rods are treaded and have nuts on the end, by tightening the nuts the wall is pulled back into place, and is held there by the soil anchors.