While some slope away from the home is a good thing, too much slope can severely affect how you use your yard. Thankfully there are a lot of great looking options to help tame steep sloped areas:
Armour Stone Retaining Walls
Armour stone refers to large block-like pieces of limestone that can be stacked to create a wall or a series of stepped walls. This can range in formality from a very straight-line wall to a looser form of wall set back into the slope with planting pockets to replicate a rocky outcropping in nature. If you are thinking of adding natural stone steps into the slope, then armour stone walls area perfect pairing. The flexibility and the natural look of the stone make this wall both structurally sound as well as beautiful. Perhaps the only slight limitation to this wall system comes from the thickness of the stones themselves. If space at the top of the wall is limited, then this wall system may not be the best choice.
Manufactured Concrete Retaining Walls
This category is the incredibly vast in options, ranging from wood timber imitation blocks to smaller stackable blocks right up to large pre-cast blocks of concrete that closely imitate natural stone. The options available through various manufacturers are nearly limitless. Some systems use a decorative fascia panel hung off structural backer blocks constructed of standard concrete while other systems rely on the massive weight of blocks weighing over 600lbs each to ensure stability. When these larger blocks are called for, we thankfully have machine mounted clamps and vacuum lifters to allow us to safely place these blocks with precision.
Pressure Treated Wood
This style of wall was used heavily after the introduction of treated wood in the 70s and 80s, but time has shown that wood in direct contact with the ground will inevitably rot leading to expensive repairs. Thankfully with the concrete options that closely resemble timbers, you can have the look of wood without the rot!
Design Considerations
Depending on your aesthetic requirements, soil type, wall height and the load behind or above the wall, we can help you select the best wall system that will be designed to easily last 50 years or longer. As with most of landscaping, it is the stuff you don’t see behind and under the wall that make the difference. We use properly compacted gravel under the wall, as well as free-draining gravel with drainage pipe behind the wall to ensure that wall doesn’t move after we install it. With various wall systems we may also need to use geogrid reinforcement as an anchor tying the wall back into the compacted gravel and soil behind it. This ingenious grid uses the retained weight behind the wall as an anchor helping keep everything in place. Another way that wall systems ensure stability is to intentionally lean back toward the slope they are retaining. Usually, this angle is no more than 10 or 12 degrees, but it makes a large difference in the engineering of a gravity wall system. Any wall constructed without this angle must be designed with greater tiebacks to ensure it doesn’t tip forward. The base of any wall regardless of material must be set below the surrounding grade to prevent the bottom kicking out over time. Failure to embed at least one row of blocks below ground can lead to the wall moving out over time. One final consideration is the local building requirements and permits. Some municipalities or conservation authorities will require that walls over a certain height be approved by an engineer. In this case, we have local engineers that can help certify a design or most manufacturers have engineers on staff as well.
Hiring a Retaining Wall Contractor
If you are hiring a contractor to construct any wall over 12” in height especially those retaining driveways or pool patios you should be certain that they have the necessary experience to properly complete the project. Another necessity is to verify that they have liability insurance as well as their status with the Workplace Safely and Insurance Board. Failure to do so could result in liability falling on your homeowner’s insurance if there is an injury or a wall failure.
If you have any questions about a retaining wall please call or text our office at 613-316-7710 and we will gladly assist you with your project.