a Retaining wall choices in materials

Which type of retaining wall is the easiest and cheapest to build

Most homeowners build fieldstone or timber walls because they are the most popular materials in my area, but modular block and poured concrete or concrete block walls also are excellent options. Each type of wall requires a different set of tools and building skills.

Railway or wood landscape ties are a good, inexpensive material for someone comfortable building with wood. A poured-concrete wall is likely the strongest choice, but the installation is probably best left to professionals.

Choosing the most appropriate material is the first decision you need to make when starting a retaining-wall project. Before you begin building a wall, you also need to consider the elevations of the new finished grades, the appropriate base and how to backfill properly.

Building two or more small walls also may be easier on your back because you don't have to lift the stone, block, or timbers too high, or set up staging. If you decide to build a terraced retaining wall, start with the lowest wall: You'll create flat areas to stand on while working on the upper walls, and you can incorporate steps, which have to be built from the bottom up.

Even the most attractive retaining wall can lose its charm if the wall is too massive for its surroundings. If there is enough area to divide the change in grade into multiple stepped walls, a series of small walls might be more visually appealing. Terraced walls also may avoid the need for permits, engineers, and complicated construction details. The area between terraced retaining walls does not have to be level and can be used for lawn or gardens.

About base and backfilling:

One truth about all retaining walls is that they are only as good as the base they are built on. The right depth and type of base depends on the material and the landscape.

Dry-laid stone walls usually are backfilled with large stones, and the voids are filled with rubble. If the wall is separated from the earth with filter fabric, drainage behind the wall often is unnecessary. Block walls should be backfilled with gravel and a perforated drainpipe and separated from the earth with filter fabric.

This method also can be used for a timber wall in a wet area, a wet-stacked stone wall, or a poured-concrete wall. Weep holes are another option for poured-concrete walls and wet stone walls.

For some projects, excavating for the base and backfill is the most laborious part of the job. If this is the case, it might be worthwhile to hire an excavator or to rent a backhoe for a day.