Retaining walls improve landscaping — if built properly

A retaining wall is meant to hold back heavy soil in areas of your property that feature a steep height difference. You’ll commonly see them near swimming pools, driveways or in multi-tiered gardens. If you’ve got a place in your yard where there’s an extreme shift in the landscaping, you’ll find a retaining wall.

Retaining walls can be made of natural materials like rock and stone, treated lumber or poured concrete. As long as it has the capacity to hold that soil in place, you can probably use it as a retaining wall material. That’s not to say I think this is a project you should do yourself.

Why? Your retaining wall has to be able to properly drain water away. When too much water gets into the soil around the wall, it can put too much pressure against wall material, potentially causing collapse. This will happen due to the ongoing freeze-thaw cycle. When the soil swells with water and it freezes, it will expand and contract. Over time, this can add enough pressure to topple over the wall.

In general, any landscaping projects around your home can negatively affect your property’s grading. The grading is how your home’s landscape gently declines away from your home, allowing water to flow away from your structure, rather than pooling around your foundation. Even adding a small garden can negatively affect your grading, so that’s why I’d bring in a landscape architect to manage your retaining wall project.

They’ll also be able to make recommendations of the right kind of material to use, depending on how your retaining wall will see use. Do you plan to place patio furniture in the area? Let them know and they can install the proper anchoring system or add a thicker base to support the extra weight.

When it comes to your retaining wall, size matters. If it’s going to be taller than four feet (1.2 metres), you’ll probably need the additional assistance of an engineer — and always check with your local building code to see if your retaining wall project requires a permit.

MAINTENANCE YOU CAN DO

Even though I don’t recommend building the wall yourself, you should be able to handle a lot of the regular maintenance items. This will keep your retaining wall in good standing for a lot longer, preventing you from having to tear it down and rebuild. So what do you need to do?

Ensure there’s good ground cover around the wall. Grass and sod help absorb water around the wall — so if you see it die off over the winter, plant some new seed, or lay some new sod. The roots can help keep all that soil in place, preventing the erosion we don’t want to see.

Meanwhile, keep up with your weeding, as they can creep into those little spaces, potentially causing small shifts of the wall over time. It will seem small at first, but this can make way for big shifts later.

For retaining walls that include a drainage pipe, make sure to keep the pipe clear of debris so water can flow properly. Not every wall needs a drainage pipe, so don’t be alarmed if yours doesn’t.

This is dependent on the materials you use: concrete will require some drainage, while more natural materials may be able to make do without.

If your retaining wall uses concrete, beware of using any salt-related products nearby, since they can cause erosion over time. I generally stick to using things like sand, rather than a salt-based de-icing product, to ensure that our four-legged friends don’t harm their paws. I recommend you make the switch, as well.

Your retaining wall is responsible for keeping your landscaping intact, and free from water intrusion. So if you see major signs of the wall failing — like the wall buckling or major cracks or holes in your material — get it looked at right away.