Should You Seal Your Interlock? The Honest Answer for GTA Homeowners

If you've had your interlock cleaned, or you're considering it, someone has probably suggested sealing it afterward. And if you've gotten quotes, you've likely noticed that sealing adds a meaningful amount to the total cost.

So is it worth it? The honest answer is: it depends. Sealing interlock is often oversold — but for the right driveway in the right condition, it's genuinely excellent value. Here's how to think through it.

What Does Sealing Actually Do?

A quality interlock sealer does several things:

• Locks in joint sand — polymeric sand activates with water, but a sealer provides additional stabilization that keeps joint sand from eroding out as quickly from rain and traffic
• Repels staining — oil, grease, and road grime sit on the surface rather than penetrating the paver, making cleanup significantly easier
• Slows efflorescence — the white mineral deposits that appear on concrete and interlock are partly caused by water moving through the paver material; a sealer reduces this moisture movement
• Enhances colour — a wet-look sealer deepens and enriches the colour of the pavers, making them look richer and more saturated (a natural/matte sealer maintains the original appearance without the sheen)
• Inhibits weed growth — a properly sealed joint is harder for weed seeds to establish in

When Sealing Makes Sense

Sealing is most worthwhile when:

• The interlock was recently installed or freshly cleaned — you want to seal clean pavers, never dirty ones
• The pavers are a premium product with a colour or finish worth preserving
• The driveway gets heavy vehicle traffic or is prone to oil staining
• You want to reduce maintenance frequency — sealed interlock requires less frequent cleaning
• The property is being listed for sale — sealed interlock photographs and shows significantly better

When Sealing Doesn't Make Sense

Sealing is a waste of money when the interlock hasn't been properly cleaned first. A sealer traps whatever is on the surface — stains, dirt, efflorescence — permanently underneath it. You cannot un-seal pavers without stripping the entire surface, which is labour-intensive and expensive.

Similarly, if your interlock has significant structural issues — shifted pavers, failed base, major joint erosion — sealing is cosmetic and doesn't address the underlying problems. Fix the structure first.

What Type of Sealer Should You Use?

Wet-look (gloss) sealer

Gives pavers a rich, deep, slightly glossy appearance as if they were wet. Popular for driveways and front entries where curb appeal is the priority. Can be slippery when wet on flat surfaces if not formulated with anti-slip additives.

Natural/matte sealer

Preserves the original appearance of the pavers without adding sheen. Provides all the protective benefits of a sealer without changing how the surface looks. Good choice for older pavers or homeowners who prefer a natural aesthetic.

Penetrating sealer

Soaks into the paver rather than forming a surface film. Excellent protection with virtually no change to appearance. Doesn't lock joint sand as effectively as a film-forming sealer, but more durable in freeze-thaw conditions.

How Long Does Sealer Last in Ontario?

In Ontario's climate — UV exposure in summer, road salt and freeze-thaw in winter — most quality sealers last 2–4 years on driveways with regular vehicle traffic. Patios and walkways with lighter use can go 4–6 years between applications.

The sealer doesn't simply stop working one day — it gradually breaks down, losing its repellency and sheen. When water stops beading on the surface and starts absorbing, it's time to reseal.

Does Sealed Interlock Require Less Maintenance?

Yes, noticeably. Stains that would penetrate unsealed pavers and require aggressive cleaning are easily wiped or rinsed off sealed surfaces. Weeds establish less readily in stabilized joints. Efflorescence appears less frequently. The overall maintenance load is lower — which is one of the main reasons regular sealing makes financial sense over the long term even accounting for the reapplication cost.

The Bottom Line

If your interlock is in good condition and has been properly cleaned, sealing is a worthwhile investment that protects your driveway, reduces maintenance, and keeps it looking great longer. If your interlock is heavily worn, structurally compromised, or dirty — address those issues first, then consider sealing afterward.

As with most property maintenance, the best time to seal is right after a professional clean — while the surface is completely clean and the joint sand has been freshly applied.