Which aggregate sizing works for Vancouver permeable paver joints?

For permeable paver joints in Metro Vancouver, use 2-8mm (No. 8 to 3/8 inch) open-graded aggregate with zero fines content. This sizing allows maximum water infiltration while providing adequate stability for the pavers in Vancouver's high-rainfall climate.

The aggregate gradation is critical for permeable paving performance in Metro Vancouver's 1,200mm+ annual rainfall environment. Standard jointing sand or polymeric sand completely defeats the purpose of permeable pavers by blocking water infiltration. The joint aggregate must allow rapid water passage while maintaining interlock stability between pavers.

Recommended joint aggregate specifications include crushed granite, basalt, or recycled concrete in the 2-8mm range with less than 2% fines passing the No. 200 sieve. The angular shape of crushed aggregate provides better mechanical interlock between particles compared to rounded gravel. Local suppliers like Lehigh Hanson, Burnaby Lake Aggregates, and Fraser Valley Aggregates stock appropriate permeable jointing materials. Expect to pay $45-65 per cubic yard for properly graded permeable joint aggregate.

Installation technique matters significantly for joint performance. The aggregate should be swept into joints when pavers are completely dry, then compacted with a plate compactor using a protective rubber mat. Multiple passes may be needed to fully fill joints as the aggregate settles. Unlike polymeric sand, permeable joint aggregate is not activated with water — it relies purely on mechanical interlock and the confining pressure from surrounding pavers.

Metro Vancouver's clay-heavy soils in Surrey, Richmond, Delta, and Langley require special attention for permeable paver systems. The entire base system must be open-graded aggregate (typically 20mm down to 5mm) with no fines, installed over geotextile fabric to prevent clay migration. Without proper base preparation, clay will eventually clog the system regardless of proper joint aggregate sizing.

Maintenance requirements for permeable joints include periodic vacuum cleaning to remove organic debris, leaves, and sediment that accumulate over time. In Vancouver's moss-friendly climate, expect to clean permeable joints annually or bi-annually to maintain infiltration rates. Power washing can actually damage the joint aggregate gradation by washing out finer particles, so stick to vacuum cleaning or gentle brushing.

When to hire a professional: Permeable paver installation requires ICPI (Interlocking Concrete Pavement Institute) knowledge of infiltration rates, base design, and connection to stormwater management systems. The specialized aggregate gradations, compaction techniques, and drainage engineering make this a professional installation requiring experienced contractors familiar with Metro Vancouver's soil conditions and municipal stormwater requirements.