Freeze-Thaw Damage in Calgary: How to Build Hardscape That Lasts

Calgary’s Freeze-Thaw Problem

Water expands 9% when frozen.
If your base holds moisture — your patio will move.

Every winter.


The 4 Must-Do Steps

1. Proper Excavation Depth

Minimum:

  • 8–12” base for patios

  • 12–18” for driveways


2. Use Road Crush (Not Washed Gravel)

Road crush compacts.
Washed gravel drains but shifts.


3. Compaction in Lifts

Compact every 2–3 inches.


4. Drainage Planning

Slope away from house:
Minimum 2% grade.


Why Most Patios Fail

  • Not enough base

  • Poor compaction

  • No edge restraint

  • No drainage slope


FAQ

How long should a properly built patio last in Calgary?
20–30+ years if installed correctly.