Short answer: yes, road salt can damage interlock over time — but mostly indirectly, and it is manageable. The bigger culprit is the freeze-thaw cycle that salt encourages, which can spall the surface of the pavers and wash out the sand in the joints. With the right ice melt, sensible use, and good winter care, you can protect an interlock driveway through Ontario winters. Here is how.
Interlock is a real investment, so it is worth understanding what actually harms it.
How salt affects interlock
Salt itself does not dissolve concrete pavers, but it drives two problems:
- Freeze-thaw spalling. Salt keeps water liquid longer and pulls moisture into the pavers; when it refreezes, it expands and can flake or pit the surface, especially on lower-quality pavers.
- Joint sand loss. Repeated melting and runoff can wash the stabilising sand out of the joints, which lets pavers shift and weeds and ants move in.
Higher-quality pavers that are well sealed hold up far better than budget ones.
How to protect interlock in winter
- Use a gentler ice melt. Calcium chloride or magnesium chloride blends are easier on pavers than plain rock salt, and you need less of them.
- Do not over-apply. More salt does not mean more melting past a point — it just means more residue and more damage.
- Clear snow promptly so you rely less on melt in the first place. Packed snow left to ice up is what leads to heavy salting.
- Seal the interlock every few years and keep the joint sand topped up.
- Reach for sand for traction on the coldest days instead of dumping more salt.
The windrow makes it worse
The dense, salty windrow the city plow packs across the end of your interlock driveway is a double hit — heavy, hard-to-move snow loaded with road salt sitting right on your pavers. Clearing it promptly rather than letting it melt and refreeze on the surface helps; we explain the windrow problem separately.
Sloped interlock needs extra care
On a sloped interlock driveway, meltwater runs down and refreezes at the bottom, concentrating both ice and salt there. That is the exact spot to favour traction and prompt clearing over heavy salting — more in snow removal for sloped and icy driveways. Prompt, careful clearing all winter is also part of our snow removal process.
Frequently Asked Questions
Does rock salt ruin interlock?
Not instantly, but over time salt-driven freeze-thaw can spall the paver surface and wash out joint sand. Gentler ice melts and sensible use greatly reduce the risk.
What ice melt is safe for interlock?
Calcium chloride or magnesium chloride blends are gentler than plain rock salt, and you need less. Whatever you use, apply it sparingly.
How do I protect my interlock driveway?
Clear snow promptly, use a gentle ice melt sparingly, keep the joint sand topped up, and reseal every few years. Use sand for grip on the coldest days.
Is sealing worth it?
Yes — a good sealer helps the pavers shed water and resist salt and staining, which pays off over many winters.
Should I just avoid salt entirely?
Not necessarily. Prompt clearing plus a little gentle ice melt is fine; the damage comes from heavy, repeated over-salting on packed snow.
Want your interlock cleared and treated with care all winter? Home Bros clears driveways across the GTA and treats every property like our own. See how our snow removal works and get a quote.