By Bennett's Concrete and Excavation, Norwich, NY. Updated October 2026.
The rules that come first
- First winter: no deicers. NRMCA's guidance on scaling says to avoid deicing chemicals in the first winter and use clean sand for traction.
- Never these: NRMCA says never use ammonium sulfate, ammonium nitrate or magnesium-based salts as a deicer. Many fertilizers are ammonium-based, so keep them off concrete too.
- After that, go easy. NRMCA says to use deicers in moderate amounts after the first winter.
How ice melt hurts concrete
There are two separate ways.
Physical. Melting snow on a cold night adds water that refreezes, so deicers add freeze-thaw cycles at the surface. NRMCA describes the result, scaling, as local flaking or peeling of the finished surface. Air-entrained concrete, proper finishing and curing help it resist. See our guide to scaling and spalling.
Chemical. An FHWA tech brief explains that calcium chloride and magnesium chloride can react with the cement paste to form calcium oxychloride, a highly expansive compound. The brief says this damage is more likely at higher salt concentrations, often shows up first at joints, and isn't prevented by air entrainment alone. In the same brief, test specimens soaked in sodium chloride showed no damage from that reaction.
Common ice melts compared
| Product | What the sources say |
|---|---|
| Sand | Not a melter, just traction. Recommended for new concrete by NRMCA and Cemstone. |
| Rock salt (sodium chloride) | Cemstone says it doesn't chemically attack concrete. It still adds freeze-thaw cycles, and Nebraska Extension notes it can burn plants. |
| Calcium chloride | Cemstone lists weak solutions as not chemically attacking concrete. FHWA warns it can form expansive calcium oxychloride, especially at higher concentrations. |
| Magnesium chloride | NRMCA says never use magnesium-based salts. FHWA raises the same oxychloride concern. |
| CMA (calcium magnesium acetate) | Nebraska Extension describes it as salt-free with little impact on plants and animals. It contains magnesium, so weigh NRMCA's warning and read the label. |
| Urea | Cemstone lists it as not chemically attacking concrete. Nebraska Extension says it burns plants less than potassium chloride but can make nearby grass green up and grow fast in spring. |
| Ammonium nitrate or sulfate | Never. Both NRMCA and Cemstone warn against them. |
Read the label
Ice melt bags are often blends, and the front of the bag doesn't always tell you what's inside. Turn it over and look at the ingredient list. If you see ammonium nitrate or ammonium sulfate, put it back. If you see magnesium chloride or other magnesium compounds, weigh NRMCA's warning before using it on concrete you care about. A bag marked "safe for concrete" may only mean safe for mature concrete in normal amounts, so check what it says about new concrete. When in doubt, sand is the one choice every source agrees on.
Use less of whatever you use
- Shovel or plow first. Ice melt should only handle the thin layer left behind.
- Spread it thin and even, not in piles.
- Sweep slush off once it's done melting. Cemstone advises not letting water or deicer stand on the surface for long.
- Fix the drip spots. Water from downspouts and roof edges that crosses a walk refreezes nightly. Redirecting it can mean less ice melt all winter.
Protecting lawns and plants
Nebraska Extension lists desiccation, stunting and dieback as symptoms of salt injury. It suggests covering nearby plants with burlap or similar cloth and flushing the soil with plenty of water after the last freeze. Piling salty snow on garden beds does the most damage, so pile it somewhere else.
Protect the concrete itself
NRMCA suggests considering a breathable sealer, applied when the concrete is reasonably dry. Cemstone recommends sealing before October 1 and resealing when water stops beading. On garage aprons, where cars drip salty slush all winter, we use a salt-repellent sealer. See concrete sealing and our first winter care guide.
