In the last twenty years, a new kind of retaining wall has been gaining popularity with homeowners, particularly the Do-It-Yourself folks. Up until now, if you wanted to build a retaining wall you were limited to the labor intensive materials of brick, stone or rock. Timbers, particularly railroad ties were easier to install but tend to only last about fifteen years before the rot requires replacement. But with the development of concrete retaining wall technology, a quicker easier method has arrived for building retaining walls.