Home/Hardscaping/Retaining Walls
HardscapingRetaining Wall Installation
in Ottawa
A retaining wall does more than hold earth. It defines spaces, creates usable land on sloped properties, and — when built right — becomes an architectural feature. When built wrong, it becomes a liability.
A retaining wall is an engineered structure — not a pile of stones.
Every retaining wall holds back thousands of pounds of earth. Add Ottawa's freeze-thaw cycles, and the pressure multiplies. Without proper engineering, drainage, and compaction, walls lean, crack, or collapse — usually after the second or third winter.
Ontario building code requires a permit for any retaining wall over 1 metre (3'3"). We handle the permit process, the engineered drawings, and the construction — start to finish. If your wall is under 1 metre, we still build it to the same standard.
Three kinds of retaining walls we build.
Armour Stone
Massive 800–1,200 lb natural limestone blocks placed by excavator. Monumental, permanent, and impossible to replicate with smaller products. Best for tall walls, estate properties, and statement entrances.
Concrete Block
Versa-Lok or Allan Block systems with integrated pins and setback. Wider colour range, cleaner lines, and faster installation than stone. Good for mid-height walls (2–5 ft) and curved layouts.
Natural Stone (Mortared)
Traditional mortared stone walls for a classic, old-Ottawa look. Best for lower walls, garden terraces, and heritage neighbourhoods where character matters more than height.
The most important part of a retaining wall is behind it.
Every wall we build includes a complete drainage system behind the wall face — this is what separates a permanent structure from one that fails in five years.
Drainage Stone
12–18 inches of clear drainage stone behind every block, not native soil. Water passes through stone, not pushing against the wall.
Perforated Pipe
A 4-inch perforated pipe at the base collects water and channels it to daylight. No standing water behind the wall, ever.
Filter Fabric
Geotextile fabric wraps the drainage stone, keeping soil fines from migrating into and clogging the drainage system.
Compacted Base
A minimum 6-inch granular A base compacted in lifts before the first block goes down. The foundation of everything above it.
Orleans Armour Stone Retaining Wall
Engineered 4 ft Armour stone wall spanning 60 linear feet with integrated drainage, backfill, and sod restoration. 800–1,200 lb stones placed by excavator. The wall runs along a sloped property line, creating a level, usable yard where there wasn't one — with a finished appearance that feels like it's always been there.
“An engineering masterpiece. The excavation was massive — they handled the permit, the city inspector commented on the drainage, and the finished wall looks like it's been there for a hundred years.”
Margaret D.
Westboro, Ottawa
Common questions about retaining walls.
Do I need a permit for a retaining wall in Ottawa?+
Under Ontario building code, any retaining wall over 1 metre (3'3") requires a building permit with engineered drawings. We handle the entire permit process — you don't need to visit city hall. Walls under 1 metre don't require a permit, but we still build them to the same drainage standard.
Armour stone vs. concrete block — which is better?+
Armour stone is heavier, more permanent, and has a natural look that suits estate properties. Concrete block (Versa-Lok, Allan Block) offers more colour options, faster installation, and works better for curved walls and tighter spaces. Your choice depends on height, aesthetics, access for an excavator, and budget. We'll walk you through both options during the estimate.
Why do retaining walls fail?+
Almost always water. Without drainage stone, a perforated pipe, and filter fabric behind the wall, water builds up pressure during freeze-thaw cycles and pushes the wall forward. The wall face itself is almost never the cause — it's what's behind it that fails. Every wall we build includes a complete drainage system.
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Ready to talk about your retaining wall?
Free on-site assessment with wall type recommendations, drainage plan, and a line-item estimate. No obligation.