Cleaning and sealing interlock, in that order, always.

Faded, grimy, moss-streaked interlock is usually not worn out. Years of surface build-up obscure the original colour. A real clean pulls that build-up off, and the right sealer keeps the restored colour looking that way. The trap is sealing over the grime, which traps it under a film and makes the next cleaning a much harder job.

The clean

A controlled pressure wash, calibrated to lift moss, oil shadows, ground-in dirt, and the white efflorescence that hazes older pavers, without blasting the surface or displacing more joint sand than necessary. Done properly, the original colour of the stone comes through, and the change is often surprising to homeowners who assumed the stone had simply faded permanently.

Choosing the right sealer

Sealer selection depends on the result the homeowner wants and the conditions the surface faces. The main categories:

• Natural-look or matte sealers. Protect without changing the colour much. The surface looks clean and protected but not wet or shiny. A common choice for light-coloured pavers where homeowners want to preserve the as-laid appearance.
• Wet-look or gloss sealers. Deepen the paver colour significantly, similar to how wet stone looks in rain. A popular choice for two-tone driveways or patios where contrast is part of the visual. Tends to show scuff marks more on driveways with heavy vehicle traffic.
• Salt-resistant sealers. Formulated to resist the winter road salt that is common on Niagara driveways. Worth specifying for a driveway that receives direct salt contact.
• UV-stabilized sealers. Block the ultraviolet exposure that fades darker pavers over time. Particularly relevant for south-facing surfaces in full sun.

The 3 to 5 year refresh cycle

Most exterior interlock sealers in the Niagara climate have a service life of roughly 3 to 5 years before they need refreshing. A driveway that takes daily vehicle traffic and heavy road salt is at the shorter end; a shaded back patio with foot traffic only is at the longer end. The refresh is less intensive than the first seal: a light clean and a new coat, without the need for the aggressive cleaning pass.

Illustrative cost ranges

Cleaning and sealing together typically runs roughly $2.50 to $4.50 per square foot in the Niagara market, depending on how much build-up has to come off and which sealer finish is chosen. It is almost always quoted as one job because doing only the clean, or only the seal, wastes either the investment or the window. Full illustrative ranges are on the cost guide.