Retaining walls are beautiful landscape structures that are built to restrain the earth behind them. They need to hold up to constant pressure as the force of gravity pushes against them. Badly built walls will fail. Failed walls will sag, crack, bulge, lean, produce large gaps, or collapse. Most of the time, the only way to fix a collapsing retaining wall is to tear it down and rebuild it.

Most retaining wall failures can be avoided. Here are 4 preventive measures you can take to make sure your retaining wall will hold up.

1. Drainage is the number one reason of retaining wall failure in the Vancouver Washington area. When water is absorbed into the soil behind a retaining wall with no place to go, the pressure behind the wall will be increased. If water continues to build up, the wall will eventually push out, causing it to bulge or collapse. Installing drain tile and using clean, granular rock for both the back fill and the base of the wall will allow water to drain out. You need to make sure that the drain pipe is ran out of the wall to move the water away from the wall. The pressure will be released and wall failure will be prevented.

2. Compaction. Bad compaction will eventually cause a retaining wall to move or shift that will produce large gaps within the wall. The soil needs to be compacted once at the point of excavation, again after the gravel base has been added, and each time backfill is added. Backfill should also be added after each course of the wall).  The best way to do this is to use a compactor.

3. Reinforcements might be needed depending on a number of factors, soil conditions, type of material being used to build the wall, and the height of the wall. The most common and best  type of reinforcement for modular block retaining walls and rock retaining walls is geogrid. Geogrid is a mesh-like fabric that lays between the wall blocks and ties back into the soil which helps stabilize the soil and secure the wall. It is usually added every 2 or 3 courses. The more clay you have in your soil, which we have a lot of in Camas and around the Vancouver area will need more geogrid.  Soils that drain like sandy ones won't need as much.

4. Engineering. Certain conditions call for a retaining wall to be professionally engineered before it can be installed. Walls exceeding a certain height (usually 4 feet) should always be engineered.  Walls that will be holding up against additional pressure, such as a retaining wall that is holding back a parking lot, should be engineered. Your local city or county ordinances may also require engineering for retaining walls.



Do your homework before you get started. If you are hiring a landscape contractor, talk to them about retaining wall failure. Make sure to review your contract carefully to make sure all the costs needed to build the wall properly are included. You should also ask if they have certified wall builders on staff. If you are going to do it yourself, be sure to follow the installation instructions. Check into your local ordinances for retaining wall requirements, and don't hesitate to consult with your supplier or a professional retaining wall builder if you need assistance.

Retaining walls will last for a long time if built the right way.  woodyscustomlandscaping.com  has certified retaining wall builders that can serve all of your wall needs.
We build rock walls, CMU walls, Manor stone, Pisa II walls and boulder walls.