How do I prevent ant hills under my Vancouver paver walkway?

Ant hills under paver walkways are prevented primarily through proper base preparation with compacted gravel and polymeric sand joints, though some ant intrusion is normal in Metro Vancouver's mild climate where ants remain active year-round.

The most effective prevention starts during installation. A properly compacted granular base (6-8 inches of crushed gravel compacted in 2-inch lifts) creates an environment that ants find difficult to excavate through. The angular, interlocked gravel particles resist tunneling much better than loose soil or sand. More importantly, polymeric sand in the paver joints creates a hardened barrier that ants cannot easily penetrate or excavate through, unlike regular sand which they can move grain by grain.

Metro Vancouver's mild, moist climate means ants remain active throughout most of the year, unlike prairie provinces where winter kills surface colonies. Pavement ants (the small black ants common in BC) are particularly persistent and will exploit any weakness in paver installations. They're attracted to the protected environment under pavers and the easy excavation opportunities that poorly prepared bases provide.

For existing walkways with ant problems, the solution depends on the severity. If you're seeing occasional small ant hills pushing up through joints, you can address this by removing the existing joint sand, applying ant control granules or diatomaceous earth to the joints, then refilling with fresh polymeric sand. The polymeric sand creates a much harder barrier once activated with water. For severe infestations where ants have undermined the base, sections may need to be lifted, the base re-compacted, and pavers relaid.

Prevention strategies include maintaining your polymeric sand every 3-5 years (more frequently in Vancouver's wet climate), keeping the area around your walkway free of food sources that attract ants, and ensuring proper drainage so water doesn't pool and soften the base material. Ants prefer moist, loose soil for tunneling, so a well-drained, compacted base is your best defense.

When to call a professional: If ant activity has caused noticeable settling or shifting of your walkway pavers, the base has likely been compromised and needs professional reconstruction. Similarly, if you're planning a new walkway installation, proper base preparation and polymeric sand application are critical enough that most homeowners benefit from professional installation to ensure long-term ant resistance.

Minor ant intrusion is manageable with good maintenance, but preventing major infestations requires quality installation from the start.