The wall
Sixty feet tall and two hundred and fifty feet long, dug ten feet into the hillside and built in multiple levels.
Project: Chilliwack Mountain
A 60 Foot Rock Wall on Chilliwack Mountain
The largest wall we have built. Sixty feet tall and two hundred and fifty feet long, holding a hillside so the property above it could finally be used.
- 60 ft tall, 250 ft long, built in levels
- 2,000 to 2,500 tons of local rock
- Engineered and permitted
60 ftTall
250 ftLong
2,500Tons of rock
How it was built
The wall came first, everything else followed
An old 1960s house sat on a slope with grass running down the hill and trees across the bank. The usable part of the property was a fraction of what the owners were paying for, so they started over.
Nothing above the bank could be planned until the ground below it was held, which made the wall the first real decision on the project. The stone came from Armstrong Sand and Gravel Ltd out of Agassiz, and ran between $350,000 and $400,000 before any excavation or machine time.
- Dug ten feet into the hillside, so the wall is anchored in undisturbed ground instead of sitting on the slope.
- Two feet of gravel under the base, for drainage and to stop uneven settlement across a 250 foot run.
- Three inch clear crushed rock behind the face, with geogrid through the backfill tying the wall and the soil behind it into one mass.
Engineered and permitted. At this height there is no version of this job that skips either.
What sits on the terrace
The wall created a level bench where there had been a bank. This is what went on it.
The sauna
A cedar sauna on the terrace, looking out over the valley that the wall made it possible to sit above.
The kitchen
A covered outdoor kitchen, built by the same crew that dug the hill. Forty five thousand dollars on its own.
The fire pit
Flagstone, a fire pit and the valley in front of it. This is the part the owners actually use.
The project in pictures
The whole project
Three years, and the wall was one part of it
Alongside the wall there was the demolition of the original house, the new build, a septic field, a pool and the finished yard. The project ran about three years and came to somewhere between $2.5 and $3 million. Two to three of our people were on site continuously through it.
- The hard part was not the rock, it was planning a job that kept changing across three years.
- What was underground did not match the plans, so the work adjusted to the ground as it was found rather than as it was drawn.
- Any contractor who promises nothing will change on a three year build is guessing.
One crew, from the first dig to the finished yard.
What this means for a smaller wall
Most of the walls we build are nothing like this one.
A typical wall
Forty to seventy feet long, kept under four feet tall where we can, and built in somewhere between a week and a month.
The same method
Compacted base, clear rock behind the face, geogrid where the height calls for it, and somewhere for the water to go.
The same crew
A thirty thousand dollar wall in a back yard gets built the same way as a sixty foot one, just smaller.