EPS12 Geofoam blocks
2 inches of gravel on all sides
Foam is very easy to work with
Our customer had a 70′ long, 3′ high retaining wall with a 5′ drop from one end to the other. It also has several turns. Using EPS12 Geofoam blocks he was able to economically resolve an engineering problem.
Here is his description of the project. “We built level steps filled with compacted sand and made sure each foam block was level before we backfilled. After each foam block was set we put broke concrete on top to keep the foam from shifting as we back filled around it with gravel. We had 2 inches of gravel on all sides and no voids. To prevent future voids due to termites we put screw eyes into the top of the step risers and pulled the risers and stakes out with pre attached ropes before we backfilled. Once the foam blocks were set on a LEVEL base and backfilled they were SOLID, no rocking or movement at all. This is a utility area on the back of my home. We will cover the foam the with gravel and walking surface will be recycled broken concrete. I am very happy with this solution that my soils engineer came up with. This was a project that anyone could do, it does not require skilled labor. The foam is very easy to work with and to cut. As with any construction project care must be taken that it is done properly. The foam is only about a third more that the cost of gravel and the reduction in labor cost to move it makes it a more economical choice. The reduction in lateral forces pressing on my retaining wall is around 80-90% so it will last much longer than if it was backfilled with gravel.”