Calgary interlock cleaning — stone driveway and patio specialists
Interlocking stone driveways and patios need more than a quick rinse. Algae embeds between stones, joint sand washes out exposing edges to movement, oil stains soak into porous stone faces, weeds root in compromised joints. Hartford's process: chemistry pre-treatment, surface cleaner pass, joint inspection, optional polymeric joint re-sand, optional sealer application. Annual cadence keeps Calgary interlock looking like the day it was installed.
Four contamination types — chemistry, surface cleaner, joint maintenance
Embedded algae on stone faces — the porous concrete or stone material absorbs moisture, algae spores root and spread. Visible as green-grey discolouration on north-facing patios and shaded driveway sections. Fixed by sodium hypochlorite pre-treatment with 10-15 minute dwell, followed by surface cleaner rinse.
Washed-out joint sand — the original installation sand between stones gradually washes out through rain, snowmelt, freeze-thaw and sweeping. Once joints lose 30%+ of their sand, stones become vulnerable to lateral movement (driveway stones rock under car weight, patio stones wobble underfoot), weeds root from below in the exposed joint space, and edge stones can shift entirely. Fixed by polymeric joint re-sand after cleaning.
Oil and grease stains on driveways — embedded automotive fluid contamination on the parking area. Surface chemistry won't lift it because the oil has soaked into the porous stone. Fixed by alkaline pre-treatment (saponification breaks down the oil) plus surface cleaner pass — visible improvement on most stains, complete removal on light-to-moderate staining.
Weed growth in joints — visible roots emerging through compromised joint sand. Surface chemistry kills existing weeds; polymeric joint re-sand prevents future growth by creating a bonded barrier weed roots can't penetrate. Together this gives 3-5 years of substantially reduced weed growth without herbicide. Pair this page with paver sealing for the post-clean sealer detail and oil stain removal for the deeper oil-treatment process.
Recent work
Four-step Hartford Calgary interlock service
Pre-treatment through optional seal — pick the stops that fit your scope
Walk + scope confirmation
Identify stone type (concrete paver, natural stone, clay), measure square footage, inspect joints, note stains. Confirm whether re-sand and seal are scoped.
Chemistry pre-treatment
Sodium hypochlorite for biological contamination + alkaline pre-treat for oil zones. 10-15 minute dwell.
Surface cleaner deep pass
21-inch surface cleaner with adjusted PSI for stone type. Multiple slow passes for embedded contamination. Wand for edges + detail.
Sealer application (optional)
Wet-look or matte finish sealer after stone fully dries (24-48 hours). Adds $400-$1,200. Re-seal in 3-4 years.
Sealer vs no sealer — when each makes sense
Sealer is an investment, not a default — assess by property profile
Sealing interlock makes sense in specific situations. High-traffic driveways (3+ vehicles, frequent guest parking) benefit from sealer because it locks joint sand in place and resists the oil staining that accumulates from parked cars. Patios used for entertaining (food and drink spillage common) benefit because the sealer resists wine, oil, and food acid staining. High-end properties where curb appeal directly affects resale benefit because the wet-look or enhanced-matte finish brightens stone colour visibly.
Sealing doesn't make sense in other situations. Low-traffic patios without entertainment use rarely accumulate enough staining to justify the sealer cost. Older interlock past its design life (15+ years, visible stone wear, cracked stones) shouldn't be sealed because the sealer locks in defects that need addressing first. Properties planning replacement within 3 years (failing joints, settled stones, drainage problems) should skip sealing and put the money toward replacement.
The sealer adds $400-$1,200 to a typical project depending on square footage and finish choice. Re-seal cadence is 3-4 years for residential, 18-24 months for high-traffic commercial. The estimator scopes seal vs no-seal during the on-site visit based on the property profile and your priorities. Pair this page with paver sealing for the sealer detail and all sealing services for the broader sealing options.
Written quotesPricing
Annual + as-neededCadence
Hartford interlock cleaningStandard
Related Hartford services
Six services that pair with Calgary interlock cleaning
Joint maintenance, sealing, and adjacent flatwork that often combines into one visit.
Five questions about interlock vs paver terminology, joint re-sand, sealing, cadence and weed removal.
Interlock and paver are largely interchangeable terms — interlock is more common in Ontario/Alberta, paver is more common in BC/US. Both describe individual stone units laid in patterns with sand-filled joints between them. The cleaning process is the same: chemistry pre-treatment for algae/biological, surface cleaner pass for embedded grime, joint inspection, optional polymeric joint re-sand if existing joint sand has washed out, optional sealer application for long-term protection. Hartford uses 'interlock' for residential driveways and patios, 'paver' for commercial pad cleaning — same crew, same equipment.
Optional service — assessed during the on-site quote walk. Joint sand washes out gradually over years (more in high-traffic areas, less in patios), exposing the stone edges to lateral movement and weed growth from below. If we see significant joint sand loss, we recommend polymeric sand re-application after cleaning — adds $150-$400 to a typical project. Polymeric sand bonds when activated with water, creating a flexible weed-resistant joint that lasts 5-7 years. If joints are full and intact, we skip the re-sand and just clean.
Cleaning removes contamination (algae, oil, grime, surface weed growth). Sealing adds a protective layer (wet-look or matte finish) that resists oil staining, slows algae regrowth, locks the joint sand in place, and brightens the stone colour. Sealing only makes sense after a deep clean — sealing over contamination locks the dirt in permanently. Hartford sealing is an add-on to cleaning, never standalone. Sealer adds $400-$1,200 depending on square footage and finish type. Re-seal cadence is 3-4 years for residential, 18-24 months for high-traffic commercial.
Annual is the Calgary standard for residential driveways and patios — chinook freeze-thaw plus prairie dust plus winter road salt brine plus seasonal organic debris (leaf staining, pollen) all accumulate visibly across a 12-month window. North-facing interlock and shaded patios under tree cover often need every-9-month cadence because of algae pressure. Commercial interlock (restaurant patios, retail walkways) typically needs quarterly cleaning because of heavier foot traffic and food/drink spillage.
Yes — and the long-term fix is joint maintenance, not herbicide. The cleaning process kills existing weeds (chemistry plus high-pressure rinse uproots them). Polymeric joint re-sand prevents future weed growth from below because the bonded sand creates a barrier that weed roots can't penetrate. Together, clean + polymeric re-sand gives 3-5 years of substantially reduced weed growth without using herbicide. Properties with chronic weed issues benefit most from the combined treatment; properties with intact existing joint sand may just need cleaning.
Calgary interlock clients
What homeowners say about Hartford interlock work
★★★★★4.9· 75 reviews on Google
★★★★★
Air Ranch interlock driveway, 280 square metres, hadn't been cleaned in 6 years. Hartford did the deep clean plus polymeric joint re-sand plus wet-look sealer. Stones look brand new, no weeds three years later.
Homeowner
Okotoks · Air Ranch
★★★★★
Patio interlock with embedded wine and food stains from years of entertaining. Hartford got 80%+ recovery on the staining and sealed the surface so future spills wipe off. Worth the sealer add-on cost.
Homeowner
Calgary · Mount Royal
★★★★★
Cracked joints with weeds growing through. Honest estimator told me sealing wouldn't help until joints were repaired. Did clean + polymeric re-sand and skipped the seal — weed problem gone, saved me $700 on unnecessary sealer.
Homeowner
Cochrane · Sunset Ridge
★★★★★
Commercial interlock walkway at our retail strip. Quarterly cleaning contract keeps it presentable through Alberta winters. Property manager loves the predictable scheduling.
Property Manager
Chestermere · Highway 1A retail
Interlock cleaning + joint maintenance
Annual cleaning is cheaper than interlock replacement
Compromised joints + neglected staining + uncontrolled weed growth shortens interlock lifespan from 25+ years to under 12. Annual cleaning plus joint maintenance every 5-7 years protects the install. Mention 'interlock' on the quote form and the estimator will scope it right.
