Q:

I need to build some retaining walls about 5 ft. high, and I thought of using tires. There are a few design problems that come to mind: how to keep the walls from tumbling forward and how to finish the top edges so the tires don’t show. Where can I get this information?

James Callear, Blairsville, GA

A:

Ken Anderson, an architect with Solar Survival Architecture in Taos, New Mexico, replies: For our construction projects, we always use tires for retaining walls, some up to 25 ft. high. Tires make an inexpensive solution that requires no concrete, wood or steel. The proper construction of a tire retaining wall involves filling the tires with dirt that’s compacted with a sledgehammer or a pneumatic tamper. We call this process “pounding the tires.” First, you place the tire on a level grade, then pound it, checking it for level. Always pound a tire in place. A 15-in. tire will take nearly 300 lb. of earth.

The wall is built using staggered courses, just like a block wall. Step back each tire course 3 in. to keep the wall from toppling and berm and tamp earth behind each completed course. A few courses of small tires can be pounded at the top of the wall for a sturdy railing. The weight of the tires and their ability to interlock with the tires below mean that no mortar or reinforcing steel is required.

To finish the wall, stuff mud, tin cans and rocks into the voids between the tires. Fill the voids in several steps until a fairly flat surface is achieved. At that time, metal lath is fastened to the tires with 1-1/2 in. deck screws. You can use roofing tins or even bottle caps to hold the lath in place. Then apply cement plaster. The final appearance is a stucco finish.

For more information on building with tires, you might want to take a look at Earthship Volume 1, How to Build Your Own, a book written by my colleague, Michael Reynolds (Solar Survival Press, P. O. Box 1041, Taos, N. M. 87571; 505-770-7056).

photo: Eugene Kim on Flickr