How thick should the gravel base be under a patio in Vancouver?

For patio installations in Metro Vancouver, you need a minimum 6-8 inch compacted gravel base, with 8 inches being the recommended standard for long-term performance in our wet climate.

The gravel base thickness is absolutely critical in Metro Vancouver because our marine climate receives over 1,200mm of annual rainfall, with 70% falling between October and March. This persistent moisture creates unique drainage challenges that make base preparation the single most important factor in paver longevity. Unlike drier climates where base depth is primarily about load-bearing capacity, Vancouver's year-round humidity and heavy winter rains mean the base must function as both a structural foundation and a drainage system.

Why 8 inches is the Vancouver standard: The extra depth compared to drier regions (where 4-6 inches might suffice) accounts for our clay-heavy soils prevalent across Surrey, Richmond, Delta, Langley, and parts of Burnaby. Clay doesn't drain well and can migrate upward into the base material over time, destroying its drainage capacity. The deeper base provides more separation between the pavers and the clay subgrade, and more storage capacity for water during heavy rainfall events.

Base material specifications: Use 3/4-inch minus crushed gravel (also called road base or crusher run) that contains a blend of stone sizes from 3/4-inch down to fines. This gradation compacts tightly while maintaining drainage voids. The base must be installed in lifts of no more than 2 inches at a time and compacted with a plate compactor to achieve 95%+ density. Many contractors try to shortcut this by dumping 8 inches and compacting only the surface — this doesn't work and leads to settling within 1-2 years.

Essential drainage components: Install geotextile fabric between the clay subgrade and gravel base to prevent soil migration. Ensure the finished patio slopes at minimum 2% (1/4 inch per foot) away from your house. For patios over 400 square feet or in low-lying areas, consider installing a perforated drain pipe at the low point, surrounded by clear drain rock and connected to your storm drain or a dry well.

When to go deeper: Increase to 10-12 inches of base if your patio will occasionally support vehicular traffic (like accessing a backyard garage), if you're building on particularly soft or wet ground, or if your property has drainage challenges. Properties in Richmond with high water tables may require even deeper bases and additional drainage measures.

Hire a professional for proper base preparation — this isn't a DIY job for most homeowners. Proper excavation, material delivery, lift-by-lift compaction with commercial equipment, and grade verification require professional tools and experience. Skimping on base depth to save $500-1,000 upfront typically results in a $3,000-6,000 rebuild within 3-5 years when the patio settles and becomes uneven.

Need help finding an interlock installer who understands Vancouver's base requirements? Vancouver Interlock can match you with experienced local contractors for free estimates.

---

Find a Interlock & Paver Contractor

Vancouver Interlock connects you with experienced contractors through the https://vancouverconstructionnetwork.com:

• Pacific West Floor Decor and Renovations ✓
• Good Old Wood ✓
• Broadway Blacktop Ltd. ✓