How much slope away from a Vancouver house is needed?

Paver installations in Metro Vancouver need a minimum 2% slope (1/4 inch per foot) away from your house — and given Vancouver's rainfall, erring toward 3% is even better for patios and driveways directly adjacent to the foundation.

That 2% figure comes from both ICPI standards and standard BC drainage practice. On a 10-foot-wide patio, 2% means the outer edge sits 2.4 inches lower than the edge against your house. It sounds subtle, but it's enough to move water decisively away from your foundation during a heavy November rainstorm — which in Metro Vancouver can mean 50-80mm of rain in a single day.

Why slope matters more in Vancouver than almost anywhere else in Canada. With 1,200mm+ of annual rainfall (and over 2,000mm on the North Shore), water that pools against your foundation doesn't just sit there — it saturates the base material beneath your pavers, softens the subgrade, and begins undermining the installation from below. Clay-heavy soils in Surrey, Langley, Delta, and parts of Burnaby make this worse, because clay holds water rather than letting it drain away. A patio that's perfectly level, or that pitches even slightly toward the house, is a slow-motion drainage disaster in this climate.

Slope alone isn't always enough. On larger patios (over 300-400 sq ft), or on properties where the grade naturally runs toward the house, slope needs to be paired with a perimeter drain or channel drain at the low point of the patio to intercept water before it reaches the foundation. A linear slot drain along the house-side edge of the patio, connected to a perforated drain pipe running to daylight or the municipal storm system, is the right solution for challenging sites. Roof downspouts discharging onto or near a paver surface also need to be directed away — either through extensions or underground pipe — before they overwhelm even a well-sloped installation.

For driveways, the same 2% minimum applies, but the direction of slope depends on your lot. Many Metro Vancouver driveways slope toward the street, which naturally handles drainage. Where the driveway runs parallel to the house or slopes toward the garage, a channel drain across the driveway apron in front of the garage door is standard practice — it intercepts water before it enters the garage or runs along the foundation wall.

Practical tips for your project:

A laser level or digital slope gauge is the right tool for verifying slope during installation — eyeballing it is not reliable enough. Your contractor should be checking slope throughout the screeding and paver-laying process, not just at the end. Ask specifically how they'll verify slope before you sign off on the work.

If you're on a sloped lot in North Vancouver, West Vancouver, Burnaby, Coquitlam, or Port Moody, drainage design becomes more complex — water moves faster, volumes are higher, and you need to think about where it's going after it leaves your patio. Directing large volumes of runoff onto a neighbour's property can create bylaw and civil liability issues, so proper drainage planning matters beyond just protecting your own foundation.

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