Over the past several years, we have noticed a lot of phone calls from individuals who are dealing with failing retaining walls. A retaining wall is intended to retain entire hillsides. If a wall is not properly installed starting at ground level then issues will arise. In the example below we found that this particular retaining wall was failing FAST. You can see clearly, from the present crack, that the wall is falling to the left & to the right. The reason for this being an improperly installed base and base course. The most important step in any retaining wall is the soil base; comprised of tamped CA6 rock. This is the point where one needs to take the extra time to ensure that the base is level, if not, the entire wall will eventually fail. After the soil base has been installed, the next step is to start laying the first course of block. At this point every block needs to be individually leveled. Once the first base course is down then we simply stack the remainder of the block in a staggered pattern (to ensure maximum strength) & back fill with CA7 rock. As you may be able to notice in the picture, there is no type of drainage for ground and or rain water. All rain and ground water needs to be able to filter through the the back of the wall and out the other side, leaving no room for water to build up behind the wall. Depending on the size and height of the retaining wall, GEO-GRID may be needed. Geo-Grid is a product that is installed behind the wall and back into the turf / hillside, giving more strength and durability.
When shopping around for someone to build and retaining wall remember these crucial steps we have pointed out. No retaining wall job is ever CHEAP and if it is I would be very very cautious. In the world of retaining walls you honestly “get what you pay for”. Paying someone thousands of dollars, only to have the wall fail will ultimately lead to paying close to triple the original price.
Please don’t make a costly mistake! Compare contractors, get pictures of jobs they have installed, ask for letters of recommendation.