How much does it cost to seal and protect an aging interlock driveway in Nepean that has been down for 20 years?

Sealing and protecting a 20-year-old interlock driveway in Nepean typically costs $800 to $2,500 depending on size and condition, but the approach differs significantly from asphalt sealcoating.

Unlike asphalt driveways that get liquid sealcoat applied to the surface, interlock pavers are protected through joint stabilization, cleaning, and selective repairs. After 20 years in Ottawa's freeze-thaw climate, your Nepean interlock likely needs polymeric sand replacement, relevelling of settled areas, and possibly some paver replacement where salt damage or cracking has occurred.

Polymeric sand replacement is the primary "sealing" for interlock driveways. The specialized sand between pavers hardens when activated with water, locking the pavers together and preventing weed growth, ant intrusion, and sand washout. After 20 Ottawa winters, your original jointing sand has likely been displaced by freeze-thaw cycles and snowplowing. Professional polymeric sand replacement costs $1.50 to $3.00 per square foot in the Ottawa market, so a typical 200-square-foot driveway runs $300 to $600. This includes removing old sand from joints, sweeping and cleaning, applying new polymeric sand, compacting, and proper water activation.

Relevelling and repairs address the settling and displacement common in older Nepean interlock. Many 2000s-era subdivisions in Nepean were built on clay soils with minimal base preparation by today's standards. After 20 years, sections may have settled or heaved, creating uneven surfaces and drainage issues. Lifting settled pavers, adding base material, re-compacting, and relaying costs $8 to $15 per square foot for affected areas. If 20 to 30 percent of your driveway needs relevelling (common after 20 years), expect $500 to $1,500 for this work.

Paver replacement may be necessary where individual units have cracked from freeze-thaw or been damaged by salt exposure. Concrete pavers from the early 2000s weren't always manufactured to today's freeze-thaw resistance standards. Replacing damaged pavers costs $5 to $12 per square foot depending on whether matching pavers are available or if you need to source similar units.

Power washing and cleaning removes 20 years of dirt, algae, and efflorescence buildup, restoring the original appearance. Professional cleaning costs $0.75 to $1.50 per square foot. Some contractors include this in their polymeric sand service since clean joints are essential for proper sand adhesion.

Nepean-specific considerations include the clay soils prevalent in many subdivisions like Barrhaven South, Riverside South, and parts of Manotick. Clay expansion and contraction may have caused more movement in your interlock than in sandy soil areas. The mature trees common in established Nepean neighbourhoods may have sent roots under your driveway, causing localized heaving that needs addressing.

Total investment for comprehensive restoration of a 20-year-old interlock driveway typically ranges from $800 for basic polymeric sand replacement and minor repairs up to $2,500 for extensive relevelling, paver replacement, and full restoration. This investment can extend your driveway's life another 15 to 20 years with proper maintenance.

When to hire a professional: Polymeric sand replacement requires precise technique — improper activation leaves white haze on pavers or creates weak joints that fail within a year. Relevelling requires understanding proper base preparation and compaction. While homeowners can handle small repairs, comprehensive restoration of a 20-year-old driveway benefits from professional expertise.

Need help finding an interlock restoration specialist? Ottawa Driveways can match you with experienced paving contractors who understand Nepean's soil conditions and the specific challenges of maintaining older interlock installations.