Why proper base preparation is the difference between a patio that lasts 25+ years and one that fails in 3. Everything Ontario homeowners need to know about interlock base materials.
If you're installing an interlock patio, walkway, or driveway in Ontario, the base is everything. Our freeze-thaw climate puts enormous stress on hardscaping. Without proper base preparation, your investment will shift, settle, and fail—often within just a few years.
As a hardscaping contractor serving Northumberland County for over a decade, we've seen the results of both proper and improper base work. This guide explains exactly what your interlock base should include and why it matters for Ontario's climate.
Great pavers on a poor base will fail. Average pavers on a proper base will last decades.
Each layer serves a critical function in our freeze-thaw climate.
The secret weapon for Ontario interlock installations.
HPB is 3/8-inch clear crushed stone—angular fragments with no fines (dust). Unlike screenings or sand, HPB doesn't retain water. In Ontario's freeze-thaw climate, this is crucial.
When water freezes, it expands. If your bedding layer holds water, that expansion pushes pavers upward. When it thaws, they settle unevenly. Over a few winters, you get the dreaded "washboard" surface.
| Material | Drainage | Freeze-Thaw |
|---|---|---|
| HPB (3/8" clear) | Excellent | Resistant |
| Screenings | Poor | Prone to heaving |
| Sand | Moderate | Washes out |
It's non-negotiable for any interlock contractor who warranties their work in Ontario.
Proper compaction is science, not guesswork.
Why base preparation matters more here than almost anywhere else.
Northumberland County experiences 50+ freeze-thaw cycles annually. Water enters the ground, freezes, expands by 9%, and pushes everything upward. When it thaws, voids remain. Without proper base drainage, your patio is constantly moving.
For pedestrian areas (patios, walkways), excavate 12-15 inches below finished grade. For driveways or areas with vehicle traffic, 18+ inches is required. This depth accommodates the granular base (6-10 inches), bedding layer (1 inch), and pavers (2-3 inches) while remaining below the frost line.
We don't recommend it in Ontario. Sand retains moisture, washes out over time, and doesn't provide the same freeze-thaw resistance as HPB. While sand is cheaper upfront, the repair costs within 5-10 years make it the more expensive choice.
Improper compaction leads to settling, typically within 1-2 years. You'll see low spots where water pools, uneven surfaces creating trip hazards, and eventually paver cracking. The only fix is removing the pavers, re-compacting the base, and reinstalling—a costly process that could have been avoided with proper initial installation.
Yes, absolutely in Ontario's clay soils. Without fabric, the native soil (especially clay) migrates upward into your base layer over time, mixing with the crushed stone and reducing drainage capacity. This "pumping" action destroys the base structure and causes failure.
With proper base preparation, quality materials, and professional installation, an interlock patio in Ontario should last 25-30+ years. We warranty our workmanship for 5 years, but the structure itself—when built right—outlives the pavers' surface aesthetics.
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Read GuideWater management solutions for Northumberland County's challenging terrain.
Read GuideWe build interlock patios, walkways, and driveways with proper base preparation that withstands Ontario's freeze-thaw cycles. 5 year workmanship warranty included.
