How to Maintain Interlocking Stone in Guelph: A Seasonal Guide

Interlocking stone is one of the most durable driveway and patio surfaces you can install in Guelph — but it's not zero-maintenance. The good news: what it requires is simple, seasonal, and mostly DIY-friendly. Here's the year-round routine.

Spring: Post-Winter Assessment

After Guelph's last frost (typically mid-April), inspect your interlocking for:

• Heaved or settled pavers: Frost heave can push individual pavers up or cause sections to settle. Small heaves often re-seat naturally as the ground thaws — watch for 2–3 weeks before intervening.
• Joint sand loss: Winter precipitation and snowblowing erodes polymeric sand over years. If you see gaps or pavers rocking, joint sand replacement is needed.
• Staining: Oil drips from vehicles, rust from metal furniture legs, and organic staining from leaves are easiest to treat in spring before they set further.
• Edge restraint integrity: Check that plastic or metal edge restraints haven't shifted. Loose edges allow pavers to creep and spread.

Spring Cleaning Protocol

1. Remove all debris with a stiff bristle broom (not metal) or a leaf blower
2. Rinse with a garden hose — avoid pressure washing at high settings, which removes joint sand
3. Treat stains: oil stains respond to degreaser; organic stains to diluted bleach (keep off plants); rust to oxalic acid-based rust remover
4. Re-sand joints if needed (see Joint Sand section below)

Polymeric Joint Sand: The Most Important Maintenance Task

Polymeric sand is the binder that holds interlocking together, prevents weed growth, and keeps ants from establishing colonies under pavers. It typically lasts 7–10 years in Guelph conditions before it needs refreshing. Signs it's failing:

• Visible gaps between pavers
• Weeds growing from joints
• Ants building hills along joint lines
• Pavers shifting or rocking when walked on

Re-sanding is DIY-possible but requires care: sweep dry polymeric sand into joints, compact with a plate compactor, sweep again, then mist with water to activate the polymer. A professional job typically costs $300–$700 for an average driveway.

Summer: Sealing and Weed Control

Sealing interlocking stone is optional but recommended for Guelph homeowners who want to preserve colour and make maintenance easier. A quality paver sealer:

• Enhances colour (wet-look or matte finish available)
• Reduces staining from oils and organics
• Helps polymeric sand last longer by reducing UV degradation
• Makes annual cleaning faster

Seal every 3–5 years. Never seal new pavers for the first season — they need to cure and any efflorescence (white salt deposits) needs to leach out first.

Fall: Pre-Winter Prep

• Apply a paver-safe weed preventer to joints in early October
• Clear leaves before they decompose and stain — wet leaves sitting on light-coloured pavers for weeks leave permanent marks
• Store metal patio furniture off pavers or add rubber feet — metal legs cause rust staining over winter

Winter: What to Use (and Not Use)

Safe for interlocking: Calcium chloride, magnesium chloride, sand for traction. These have minimal chemical effect on concrete pavers.

Avoid: Rock salt (sodium chloride) at high concentrations can contribute to spalling on some paver types over many years. Ammonium-based fertilizers used as deicers — these are genuinely damaging.

Snowblowers: Use a plastic-shoe snowblower or raise the blade slightly to avoid scraping paver surface and joint sand.