August 31, 2011
It’s interesting how humans often fail to notice what they don’t appreciate. For instance, retaining walls are found around many homes, businesses and schools, but until you realize you might need a one, you probably don’t pay much attention to the retaining walls in your neighborhood.
The following is a look at what retaining walls are and how to tell if you need one, as well as a discussion of some retaining wall design options to beautify your house landscaping.
The Functions of a Retaining Wall
Retaining walls are often found in places where extra support is needed to prevent the earth from moving downhill with erosion. The most basic function of a retaining wall is to battle gravity; the lateral force of the slope must be offset in the retaining wall’s design. Retaining walls can also:
Provide usable land. For millennia, humans have used retaining wall techniques to create terraces of usable land on slopes. Consider the incredible terraces of ancient South American civilizations; farmers in Peru’s Sacred Valley still use the area’s Andinas, or agricultural terraces, to grow lush produce. A retaining wall can serve the same purpose (albeit on a much smaller scale) for your house; landscaping is much easier when you have a level area in your yard.
Manage water runoff. Retaining walls also help slow the flow of rainwater; in this way, they can increase the utility of your gardening and lawn care. Portland homeowners can help keep polluted street water out of nearby rivers by installing a water-thirsty retaining wall system, perhaps with a rain garden incorporated in its design.
Provide extra seating. Once your retaining wall is up, it may provide several unanticipated services; landscaping seating is an example. Depending on the location of your retaining wall, it may prove to be a popular place to sit and chat.
You Might Need a Retaining Wall If…
1. You need a way to control downhill erosion. If mountains of erosion materials are clogging important areas on your property, adding a retaining wall is a wonderful idea. Retaining walls minimize erosion by decreasing the angle of a slope and holding back soil.
2. Your home is downhill from soil fault lines. As any landscaping contractor will tell you, even if erosion isn’t threatening your home now, it could under the right conditions. In an earthquake, land typically slides away from fault lines. If your home is located downhill from a fault line, a retaining wall can provide stability and peace of mind.
3. Your foundation is threatened by a sliding hill. Erosion can threaten your home’s foundation. If the soil around a downhill foundation is washing away, or erosion from a slope is compacting an uphill foundation, a retaining wall can help. In such cases, building retaining walls is one of the most important services landscaping and contracting companies perform.
Improperly installed retaining walls can bulge, crack, or lean. This occurs because either the contractor failed to build a strong enough wall to hold back the pressure of the hillside, or no drainage mechanisms were included in the wall’s design. If you live in a wet location, ask about draining options when researching retaining wall services. Landscaping design should last a lifetime, and your retaining wall will be better equipped able to hold back gravity for years to come if you include drainage solutions.
Timber walls. Typically, timber walls are the least expensive retaining wall design; they often run about $15 per square foot. However, you should keep in mind that timber walls may not last as long as other retaining wall options, since moisture in the soil can weaken the timber.
Interlocking blocks or poured concrete. For just $5 extra per square foot, you can have an interlocking block or poured concrete retaining wall. These designs pair well with homes and businesses with a modern sensibility.
Natural stone. For about $25 per square foot, you can build a natural stone retaining wall. This most expensive retaining wall option is also usually considered the most attractive. A natural stone retaining wall has oodles of character; it can turn a drab corner into an inviting, intriguing locale.
Whichever design you choose, it’s best to hire a professional engineer or house landscaping expert to install your new retaining wall. Don’t automatically contract with the outfit that provides your lawn care; Portland offers many full-service landscaping companies that specialize in landscape construction projects such as retaining walls.
A professional landscaping contractor will have years of experience to bring to your retaining wall project; that valuable experience can help you avoid an engineering catastrophe. For example, a poorly constructed retaining wall can suddenly break, unleashing a flood of stones and mud. Also, consider that retaining walls contribute to the stability of your house. Landscaping that is improperly packed behind a retaining wall can shift, taking your home with it.
For these reasons, building a retaining wall is one time when it just makes sense to arrange for professional services. Landscaping companies can help you create a retaining wall that will look great and stand up to years of extreme weather.
Do I really need a retaining wall? ›
You need a way to control downhill erosion. If mountains of erosion materials are clogging important areas on your property, adding a retaining wall is a wonderful idea. Retaining walls minimize erosion by decreasing the angle of a slope and holding back soil.How important are retaining walls? ›
Retaining walls make sloped areas functional. Essentially, the walls flatten the slope so that water and soil don't flow downward. Retaining walls can also help provide pedestrian access to a sloped area. Instead of walking up and down the slope, a retaining wall makes it easier to walk since the area is flat.At what height do you need a retaining wall? ›
The ideal height for a retaining wall is around five feet in the most optimal conditions. The best type of conditions for building a retaining wall is sandy soil that drains easily. Soil that is high in clay puts a lot of pressure on the new wall and it gets even heavier when it's wet.What happens if you don t put drainage behind a retaining wall? ›
If there is no drainage, water will compromise the safety and structure of your retaining wall. It's vital that the wall is repaired or replaced if measures to ensure drainage weren't taken. This can lead to an extensive amount of damage on the property, the expense of repairs and installation of a new wall.How much value does a retaining wall add? ›
A retaining wall can add up to 15 percent to a home's value and an average of 100- to 200-percent return on investment.