How deep should a paver base be in the GTA?

Every quote you get will use the word "base". Almost none of them will tell you how deep it goes, and that is the number that decides everything.

Foot traffic versus vehicles

A patio or walkway carries people. A driveway carries a car, an SUV, a delivery truck and a plow. Those are different loads and they need different build-ups. A contractor quoting the same excavation for your patio and your driveway is quoting a driveway that will rut within a few seasons.

Why our winters change the number

Southern Ontario goes through dozens of freeze-thaw cycles every winter. Any water sitting in the base freezes, expands about nine per cent, and lifts whatever is above it. A deeper base of clean, free-draining granular gives that water somewhere to go before it can do the lifting.

Compaction in lifts, not in one dump

Depth alone does not help if the material is placed in one thick layer. A plate compactor only influences the top portion of what it runs over. Material has to go down in thin lifts, each compacted before the next one lands on it. That is slow, it is invisible in the finished job, and it is the first corner cut when a price has to come down.

What to ask

• How deep do you excavate for this surface?
• How many lifts do you compact, and at what thickness?
• Is the spoil hauled away, or spread on the property?
• Is geotextile used where the subgrade is soft clay?

If one quote is dramatically cheaper than the others, the difference is almost always here. Ask all three contractors these four questions and the gap usually explains itself.

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