PROPER UPKEEP IS ESSENTIAL FOR STRONG RETAINING WALLS
If you take a walk around your community, you’re likely to see many of your neighbours have retaining walls on their property. Some may be big, others small and simple. But if you take a closer look, you might see that some of them are starting to fall into a state of disrepair.
Retaining walls are built on your property to hold soil behind it, retaining a difference in ground level. You could have a retaining wall that’s meant to keep soil from sliding away and provide erosion control or may be just for esthetic purposes.
For a lot of homeowners, retaining walls help enhance your plantings or even provide some extra usable space to your yard, as well as adding to the curb appeal of the space. Retaining walls aren’t complicated structures, but they need to be maintained to keep your property protected. Even smaller retaining walls are responsible for holding back loads of saturated soil — and if yours isn’t up to the task, you could start to see issues.
Here are a couple of common problems you might see with a retaining wall, and what to do to protect it: Problems with water: One of the largest problems you can have with your home is when water gets places that it shouldn’t. When soil gets wet, it gets heavier, and that can put a strain on your retaining wall if it wasn’t designed to support that extra weight. If this is happening, it’s likely that your wall isn’t equipped to allow the water to drain through as it should. To create better drainage, replace the current soil with gravel and line the base of the wall with a perforated tile to drain that water out. It’s similar to the weeping tile system you have around your foundation. Grading matters, too. The ground around the retaining wall needs to be sloped to drain and prevent excessive water from getting behind the wall. Problems with frost: Here in Canada, we have to consider the frost line when we build a retaining wall. As the ground freezes and thaws, it moves up and down — and if you’ve built your wall on top of that line where the ground freezes, it means the wall will also rise and fall as the soil moves. It’s called frost heaving, and as the soil freezes and heaves upwards it breaks the wall apart. You need to make sure you dig down deep enough to rest the footing of the wall below the frost line (typically four or five feet, or 1.22 to 1.52 metres, deep). You should be able to quickly search online for the frost line in your area. For extra protection, you can use concrete block to fill up to the ground level, and place your retaining wall material on top. Further, make sure you’ve placed gravel below and behind the concrete to help minimize the effects of frost heaving.
BEFORE YOU BUILD
The material you choose for your retaining wall will also play a role in its lifespan. I’ve seen a lot of retaining walls made from wood — and generally I don’t like that. Wood will decompose faster than stone or brick and, as it breaks down, so will the strength of your retaining wall. I have seen some really well-done wood ones but, overall, I have repaired a lot more wood retaining walls than stone ones.
How tall do you need your retaining wall to be? If you want one that’s more than four feet (1.22 m) tall, you may need to bring in an engineer to help calculate the support needed for a wall of that size. And make sure you’re always checking your local building codes to see what’s permitted in your area.
Disputes with the neighbours can be common when undertaking new construction projects. Before you build a new retaining wall, make sure you’re doing your due diligence: that is, checking your property lines to ensure that you’re not building on anyone else’s land or changing drainage patterns that may affect your neighbours.
If the wall already exists and is in need of repair, determining whose property it falls on can help dictate who is responsible for taking on that project. However, if both parties benefit from the wall, it’s worth trying to find a good solution that maintains harmony in the neighbourhood.
A retaining wall may seem like a small project, but it provides key protection to the landscape around your home — and if not taken care of, can leave you with a big retention headache! Watch Mike Holmes in his series, Holmes Makes It Right, on HGTV. For more information, visit makeitright.ca.