A retaining wall is commonly used in landscaping to either make better use of a slope or create a decorative statement. Regardless of the reason why a retaining wall is used, it is typically constructed of a material such as brick, concrete, stone or wood timbers. Depending on its purpose, a retaining wall can be very short or very tall. With proper retaining wall drainage and construction, it can bring a lot of character and function to your landscaping.
Retaining walls are a seemingly simple enhancement to any landscaping project. However nearly 80% of all residential retaining walls fail at one point or another because of poor drainage. Even though it is often passed over to reduce the cost of the project, retaining wall drainage is the most important aspect of its structure.
If water and soil find their way into the structure of your retaining wall, it can very quickly create a disastrous outcome, potentially destroying all of your hard work. For this reason, you should consult a professional very thoroughly before starting on any retaining wall project.
What are some of the things that you can do to ensure that your retaining walls have adequate drainage?
Retaining Wall Drainage Tips
Use backfill properly
Whenever you hear the term “backfill,” it means the dirt that rests immediately behind your retaining wall. Rather than just filling in with garden soil, clay or any other material that you may have, it is very important that you use at least 12 inches clean crushed stone as backfill. Beyond this point, it is completely ok to use compacted soil extracted from the area where you are doing the project. If you have plans to landscape behind the wall, use at least six inches of native soil over the gravel backfill.
Lay perforated piping
In addition to the foot of backfill that is used behind your retaining wall, you should also make sure that perforated piping is laid at the bottom of the backfilled portion of the wall. This helps create a hollow channel for water to go in the event of a heavy rain or watering. This piping can then be used to divert the water away from your retaining wall so that you do not have to worry about it collecting behind the wall, causing pressure and decay.
Install weep holes
Another important aspect of your retaining wall drainage plan is to have properly installed weep holes. Work with your landscaping expert to ensure that these holes are appropriately placed and sized to ensure that any excess water can drain through the wall. This will essentially give any moisture an additional route away from your wall, which is your ultimate goal.
A retaining wall project is a major investment in both time and money. You will want to do everything in your power to ensure that the effort that goes into creating a retaining wall is not wasted. Because of this, make sure that you don’t make one of the most common (and most destructive) mistakes that any homeowner can make: cutting corners in the project and eliminating proper retaining wall drainage. By spending a little bit of extra time and a few more dollars on the project, you can ensure that your wall drains properly and will remain in place for many years to come.