Ottawa’s Retaining Wall Company

Reasons to Use Retaining Walls

Retaining walls are one of the best ways to solve grade changes and create a cleaner, more functional landscape, especially on sloped Ottawa properties.

• Retaining walls let you terrace a slope into flat, functional areas for patios, gardens, walkways, or lawn space.
• By holding soil in place, a retaining wall helps prevent shifting, washouts, and the gradual loss of topsoil on sloped areas.
• Proper retaining wall design includes surface grading and drainage planning so water is directed away from problem areas.
• A well-built wall system uses gravel and drain piping to move incidental water away and reduce internal forces on the wall, helping the wall and surrounding areas stay stable.
• Retaining walls create clean lines, defined planting zones, and a more “finished” look, especially when paired with interlock, steps, and garden beds.

Use Cases

Retaining walls are most useful anywhere you need to manage a grade change, stabilize soil, or create clean, usable space in the landscape.

• Great for turning a slope into flat zones for patios, gardens, walkways, or lawn areas.
• Walls help create a stable edge and a clean transition where hardscapes meet changes in elevation. (Wall design must account for nearby surfaces, drainage, and loads.)
• Ideal when you need a smooth, safe “walkable” transition between two levels in the yard.
• Retaining walls can form clean, permanent raised planters that add structure and reduce erosion around beds.
• Walls provide lateral support to hold soil in place and reduce downslope movement and washouts.
• Useful where a narrow corridor or edge needs to be held back cleanly and stay stable over time.

Permits & Safety

Retaining walls can be more than a landscaping feature, they can be a structural element that needs to be built (and sometimes engineered) for safety and long-term stability. In Ontario, a retaining wall that exceeds 1,000 mm (1 m) of exposed height may be treated as a “designated structure” when it’s adjacent to public property, access to a building, or private property where the public is admitted.

What this means for homeowners and property managers:

• Some walls require a building permit and engineered drawings (depending on height and where the wall is located).
• Guards/railings may be required in situations where people have access to the open space at the top of a designated retaining wall.
• During quoting, we’ll help you identify whether your wall may trigger permit/engineering requirements, and if it does, we can coordinate the process so the wall is built correctly and safely.

Requirements vary by site and wall height, we’ll help confirm what applies before build day.

Design & Drainage Are Key

A retaining wall is only as strong as what’s happening behind it. Proper wall design assumes water won’t be allowed to build up as hydrostatic pressure, so grading and drainage have to be planned from the start.

Here’s what we focus on to build retaining walls that stay stable long-term:

• We shape the surrounding landscape so surface water is directed away from the wall instead of collecting behind it.
• We excavate to suitable material, install granular base materials, and compact in lifts so the wall has a solid foundation.
• Many systems call for a clear-stone drainage layer immediately behind the wall to move water down and out.
• A drain pipe at the base of the gravel/drainage fill is a common detail for collecting and evacuating incidental water.
• Filter fabric helps prevent soil fines from migrating into the drainage stone and clogging the system.
• For taller walls, curves, or more demanding conditions, geogrid reinforcement may be required as part of the wall system.

Maintenance for Retaining Walls

A well-built retaining wall should perform for years with minimal upkeep, but it’s worth doing a quick check each season, especially after heavy rain or rapid freeze-thaw cycles.

• Make sure any drain outlets “to daylight” stay visible and aren’t buried, and that water can flow freely away from the wall.
• Maintain positive grading so water doesn’t pond behind the wall, cascade over the face, or erode the base. Be mindful of sprinklers/irrigation so the area behind the wall isn’t constantly saturated.
• Look for cracks, bowing/bulging, leaning, movement/settlement, or erosion at the top, ends, or bottom of the wall.
• Keep planting from interfering with the wall and watch for leaning shrubs/hedges or uprooted vegetation, these can be early signs of movement.
• Don’t add heavy structures (sheds, pools, additional walls, etc.) or operate heavy equipment close to the top of the wall unless it was planned in the original design.
• Avoid excavating close to the base or cutting into the soil behind the wall, as this can compromise the foundation/reinforced zone.

If you notice significant movement, bulging, cracking, or persistent wet/saturated soil behind the wall, it’s best to have it assessed by a qualified professional before the issue worsens.