Protecting Concrete and Asphalt From Winter Salt and Freeze-Thaw
Winter is hard on driveways, walks, and parking lots — de-icing salt and constant freeze-thaw do real damage. Here’s how to protect your concrete and asphalt through the season, and set up for spring.
Road salt and freeze-thaw are the two biggest threats to pavement in the Quad Cities, and both peak in winter. A little care now prevents the spalling, cracking, and potholes that show up when the snow finally melts. Here’s what’s happening and what to do about it.
Two threats: salt and freeze-thaw
De-icing salt causes concrete to flake and crumble (spalling), and freeze-thaw pries cracks open in both concrete and asphalt. You protect your surfaces by sealing them, going easy on salt, shoveling promptly, and lining up crack repair and sealcoating for spring.
What salt does to concrete
De-icing salt — and the brine that drips off vehicles — drives extra water into the surface and accelerates freeze-thaw right at the top layer. The result is spalling and scaling: the surface flakes, pits, and crumbles. Newer concrete is especially vulnerable, but any unsealed concrete is at risk.
How de-icing salt spalls concrete
What freeze-thaw does to asphalt
Water seeps into small cracks in asphalt, freezes, expands about 9%, and widens them — over and over all winter. That’s how small cracks become big ones and how potholes form once the base underneath washes out. Cracks that go into winter unsealed come out noticeably worse.
How to protect your surfaces this winter
- Seal concrete — a good sealer is the best defense against salt and water. (See caring for new concrete.)
- Go easy on de-icing salt — use sand for traction where you can, and avoid products with ammonium nitrate or ammonium sulfate, which attack concrete.
- Shovel promptly — don’t let meltwater sit, refreeze, and work into the surface. Use a plastic-edged shovel, not metal.
- Don’t pile salted street snow onto your driveway or walks.
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Planning interior work too? Interior foundation repair and basement waterproofing — book by April 1. Winter spots are limited and filling up.
Set up for spring
Winter is the right time to plan spring surface work. Cracks that opened up over the season should be filled and surfaces resealed once the weather warms — sealcoating season runs roughly May through early fall here, and it books up fast. Getting on the schedule now means your driveway or lot is protected before next winter. (See how long sealcoating lasts.)
Common questions
Does road salt really damage concrete?
Yes. De-icing salt drives water into the surface and speeds up freeze-thaw there, causing the concrete to flake and crumble (spalling). Sealing and minimizing salt prevent it.
What’s safer than salt for my driveway?
Sand for traction is easiest on concrete. If you must melt ice, avoid ammonium-based products; calcium chloride is gentler than rock salt, but less is always better.
Should I sealcoat asphalt before winter?
If it’s due, sealing before winter helps keep water out of the surface. If it’s too late in the season, plan it for spring — and fill any open cracks as soon as weather allows.
My concrete is already flaking — can it be fixed?
Surface spalling can often be addressed, and sealing prevents it from spreading. Badly damaged sections may need replacement. We can take a look and tell you honestly.