Interlock Maintenance in Ontario: Sand, Sealing, and Winter Care
Interlock patios and driveways are low-maintenance, but they are not zero-maintenance - especially in Ontario, where 60+ freeze-thaw cycles and winter road salt work on every exposed joint. Skip basic maintenance and an otherwise perfect interlock patio starts shifting, greying, and weeding at year 5 instead of year 25. This guide covers exactly what to do, in what order, and how often, for pavers installed across Hamilton, Burlington, Oakville, Milton, and Mississauga. Every recommendation matches ICPI installation guidance and what Seven Stones Landscape does on its own customer callbacks.
Year 1: settle-in and first inspection
The first year is when the base consolidates and the polymeric sand proves itself. During the first 6-12 months after installation:
- Let polymeric sand cure undisturbed for at least 48 hours after activation - no rain, no hose rinse, no sweeping.
- Re-top joints after first rain. It is normal for a millimetre or two of polymeric sand to settle into pore spaces. A simple sweep-in re-topping is part of the ICPI-recommended install sequence.
- Do not pressure wash the first season. High-PSI water strips polymeric sand from joints.
- Inspect edges after the first spring thaw. If edge restraint spikes have shifted, this is the cheapest time to correct them.
If your contractor does not return for a 6-month walkthrough, you can walk the perimeter yourself: look for open joints, edge lift, and any settled pavers. Seven Stones Landscape books a free 6-month inspection with every patio and driveway we install.
Polymeric sand top-up cycle
Polymeric sand is the single most important wear item on an interlock install. It locks joints, resists weeds and insects, and prevents water intrusion into the bedding layer. It also breaks down gradually under UV and freeze-thaw, especially on driveways and high-traffic patios.
- Inspect annually every spring. Run your fingers along joints. If sand is more than 3 mm below paver chamfer, it is time to top up.
- Full re-sand every 3-5 years on residential patios, 2-4 years on driveways with heavier use.
- Product choice: use the same brand as your installer applied, or a premium brand-compatible polymeric like Alliance Gator SuperSand Bond or Techniseal HP NextGel. Cheap polymeric haze on the paver surface is the most common mistake.
- Install conditions: dry pavers, 0 to 80% humidity, no rain within 2 hours of activation. Early morning in late spring is ideal in Ontario.
If joints are very open or weedy, do not just re-top - sweep out the old sand first, power-wash joints to 1.5 inch depth, let pavers dry completely, then install fresh polymeric sand per manufacturer directions.
Sealing: when, what, how often
Sealers are optional but worth considering on:
- Driveways exposed to road salt and vehicle fluids.
- Pool surrounds where chlorinated water splashes.
- Patios where owners want deeper colour saturation (wet look).
Guidance for Ontario installs:
- Wait 12 months after install before sealing so efflorescence can complete its first cycle.
- Use a penetrating sealer matched to your paver manufacturer. Film-forming sealers look good at year 1 and look terrible at year 3 when they yellow or peel.
- Re-seal every 3-5 years on driveways, every 5-7 years on patios, based on how water beads on the surface.
- Apply clean and dry. Pavers must be clean and moisture-free; a bad seal traps dirt and moisture under a glossy layer.
Skipping sealer does not shorten paver life. It can shorten the aesthetic life - colours soften with UV, and deep reds especially benefit from a sealer at year 1-2.
Weed control that does not wreck joints
Weeds grow in wind-blown dust deposited on top of polymeric sand - they do not actually root in the base. That means the goal is to:
- Sweep debris off the surface so weed seeds have nowhere to germinate.
- Spot-treat any weeds that appear with horticultural vinegar or a targeted herbicide approved for paver joints. Avoid boiling water (expands joints) and flame weeders (can scorch paver surface).
- Re-sand at the first sign of open joints rather than waiting.
A fully sanded joint simply has no room for a weed to take hold. Chronic weeding means your polymeric sand is due for a full refresh.
Winter care: shoveling, salt, and alternatives
Ontario winters are the hardest test your interlock will face. Rules:
- Shovel with a plastic or rubber-edged shovel. Metal shovels chip paver edges and chamfers over time.
- Skip rock salt (sodium chloride) if you can. It is the most corrosive option for the adjacent concrete surfaces and for any metal edge restraints.
- Calcium chloride or potassium chloride are gentler and work at lower temperatures.
- Sand for traction is harmless to the paver but should be swept up in spring before it abrades the surface underfoot.
- Never chip ice off pavers with a metal bar - you will spall the paver surface.
If you have a heated driveway or use a snowblower, set the auger 1/4 inch higher on interlock than on concrete to avoid scraping the surface.
Annual spring and fall checklist
A quick twice-a-year walk saves large repair bills later:
- Spring: inspect edges, re-top polymeric sand on open joints, spot-treat early weeds, check that drainage points daylight freely.
- Fall: deep sweep and rinse, check pool surrounds for any pavers lifted by root pressure, clean polymeric sand dust off paver surface before the first freeze.
- Every 3-5 years: full polymeric re-sand and, if sealed, re-seal.
When DIY stops and a repair starts
Some maintenance tasks are DIY-friendly. Others tell you the base is failing and cosmetic work will not help. Call in a contractor when you see:
- Large dips or waves in the paver surface - base is settling.
- Pavers spreading outward at the edge - edge restraint has failed.
- Water pooling or running toward the house - drainage or slope has shifted.
- Joint sand disappearing every season - water is moving under the surface.
For any of these, our interlock repair team diagnoses the base before any cosmetic re-sanding. See also our guides to patio sinking repair and uneven interlock for symptom-specific detail.
Keep your install in year-one shape
Interlock maintenance is mostly annual sweeping, watchful joints, and one polymeric re-sand every 3-5 years. Do that, and your patio or driveway will look structurally identical at year 25 as it did the week it was laid. Let it slide, and year 5 is when you start seeing shifting, weeding, and greying that costs real money to reverse. If you want your install walked through once with a contractor who built it to ICPI specs, Seven Stones Landscape offers free maintenance inspections to homeowners across Hamilton, Burlington, Oakville, Milton, and Mississauga. Book yours today.