Retaining Walls & Steps · Cambridge
Retaining Walls and Steps in Cambridge
A retaining wall holds back soil and, more importantly, the water in it. Walls do not fall over because the blocks were wrong; they fall over because nobody dealt with the water behind them.
Cambridge is a city of river valleys and the slopes that go with them, and many lots in Galt, Preston and along the Speed in Hespeler have a grade change that a wall has to manage. Retaining walls are also where interlock meets the building code: the City of Cambridge's building permit page lists retaining walls greater than 1 metre, depending on location, among projects that need a building permit, and its by-law page says a permit is not necessary under 1 metre. A wall at or over that height, or one that holds up a driveway, a pool or a neighbour's yard, is engineered and permitted rather than built on a hunch, and that gets settled before the quote.
What holds a wall up
- The base. A compacted granular footing below grade, with the first course buried and dead level. A wall built on a scraped lawn moves with the first frost.
- Drainage behind the wall. Clear stone backfill and a perforated drain at the base that daylights somewhere water is allowed to go. Water held behind a wall freezes and expands, and the wall leans a little further every year.
- Setback and geogrid. Segmental blocks step back into the slope by design, and walls above the manufacturer's gravity height need geogrid reinforcement laid back into compacted fill. This is the part a permit drawing shows.
- Separation fabric between the native soil and the stone so fines do not clog the drain.
Garden walls and seating walls
Not every wall is holding back a slope. A low wall that frames a patio, a planter wall along a walkway, or a seating wall around a fire pit is a smaller structure with the same basic rules: a compacted base, a buried first course and somewhere for water to go. These are quick to build and they are where most of the visual value in a landscape comes from.
Steps
Front steps are the piece of interlock that moves most, because they sit on fill against a foundation and they carry the most freeze-thaw. On the century houses in Galt the original stone steps have often been replaced with poured concrete that has since cracked and tipped. New steps are built on a compacted base to depth, with each riser bedded on a solid core and, where the approach falls toward the house, with drainage at the bottom tread. In a Heritage Conservation District such as Dickson Hill or Main Street, the step material and profile are part of what the City's heritage staff look at, since exterior alterations there need a permit under the Ontario Heritage Act.
What to expect
A garden or seating wall is typically one to two days. A retaining wall holding a real grade change is two to five days depending on length, height and how much backfill moves. The quote depends on height, length, what the wall is holding, access for material, drainage routing and whether an engineer's drawing and permit are needed.
Frequently asked questions
Do I need a permit for a retaining wall in Cambridge?
The City's building permit page says retaining walls greater than 1 metre may need a permit depending on location, and the by-law page says under 1 metre does not. Anything near that height, or holding up something that matters, gets confirmed with the City's building division before it is quoted.
Why is my existing wall leaning?
Nearly always water: no drainage behind it, or a drain that clogged with fines, so saturated soil freezes and pushes. Sometimes a missing base course. A leaning segmental wall can often be taken down, the base and drainage rebuilt, and the same blocks relaid.
Can you match my existing block?
Often. Many segmental wall systems have been in production for years. Where a style is discontinued, we show you the closest current match or suggest where a deliberate change in material looks intended rather than accidental.
Serving Cambridge and surrounding areas. Contact us for a no-obligation quote specific to your property.