Should I refresh polymeric sand before Ottawa winter?

Yes, refreshing polymeric sand before Ottawa's winter is excellent timing and one of the most important maintenance tasks for interlock driveways. Fall application (September through early October) gives the sand time to cure and harden before freeze-thaw cycles begin.

Why Fall Timing Matters in Ottawa

Polymeric sand needs warm, dry conditions to activate and cure properly — ideally temperatures above 15°C with no rain for 24-48 hours after application. Ottawa's unpredictable fall weather makes September and early October the sweet spot. The sand forms a semi-rigid bond that locks pavers together and prevents winter damage from frost heaving, snow removal, and ice formation in the joints.

Old or deteriorated polymeric sand allows water to penetrate deep into the joints, where it freezes and expands, pushing pavers apart and creating an unstable surface. Fresh polymeric sand acts as a barrier, keeping water on the surface where it can drain away or be removed during snow clearing.

Signs You Need Fresh Polymeric Sand

Look for sand that's washing out of joints, weeds growing between pavers, ant hills in the joints, or joints that appear loose or crumbly. If you can easily scrape sand out with a screwdriver, it's time to refresh. Ottawa's freeze-thaw cycles break down polymeric sand faster than in milder climates — most Ottawa interlock driveways need fresh sand every 3-4 years.

Application Process

Remove old sand from joints using a pressure washer, joint scraper, or stiff brush. Let the surface dry completely, then sweep new polymeric sand into joints, ensuring they're filled to within 3mm of the paver surface. Compact gently with a plate compactor (use a rubber pad to protect pavers), sweep excess sand, then activate with a fine mist spray. Follow the manufacturer's activation instructions precisely — too much water can cause the sand to wash out before curing.

Professional vs DIY

This is a manageable DIY project for most homeowners if you have the right tools and good weather. However, if your driveway has significant settling, widespread loose pavers, or drainage issues, hire a professional who can address the underlying problems during sand replacement.

Need help finding a driveway contractor for more extensive interlock maintenance? Ottawa Driveways can match you with local professionals through the Ottawa Construction Network.