De-Icers and Snow Melters

Comparison of snow and ice melting products and their downsides

Icy winter weather conditions often create a need for the application of de-icers to slippery sidewalks, steps and driveways. Safety concerns often take priority over potential damage to paved surfaces, lawns and landscape plants, which may result from the use of certain de-icing products. This page describes the various deicer products.
Spalling Concrete
The most common damage to concrete is spalling, and results from the concrete surface becoming pitted. Some de-icing products cause less damage to pavement. Also, sealing concrete in advance of winter weather can help prevent damage to concrete surfaces from de-icers.
Lawn Damage
One defensive measure used by groundskeepers to minimize damage to lawn grasses from de-icers is an application of gypsum (calcium sulfate) to lawn areas bordering sidewalks, driveways and roadways. Applications of gypsum are best made in the fall of the year, prior to the onset of winter weather and subsequent de-icer applications.
Below is information on the most commonly used de-icers:
Calcium Chloride
Effective  temperatureDown to -25°F to -50°F
Fast-acting at all temps, since it gives off heat as it dissolves.
ConcreteDoesn’t attack concrete chemically.
VegetationWon’t harm vegetation at the recommended rate.
ResidueNo powdery residue.
Note: Sometimes used in roof gutters to melt ice dams.
Magnesium Chloride
Effective  temperatureDown to 5°F
ConcreteIncreases the number of freeze-thaw cycles, which can damage concrete from freeze-induced expansion. Gradually attacks concrete chemically.
VegetationEnvironmentally safer than Calcium Chloride and Sodium Chloride, but does contain more chloride than other salty de-icers.
ResidueTracks less than Calcium Chloride.
Potassium Chloride
Effective  temperatureDown to 12°F
ConcreteIncreases the number of freeze-thaw cycles, which can damage concrete from freeze-induced expansion. Doesn’t attack concrete chemically.
VegetationOne of the safer de-icers around vegetation. Considered environmentally safe.
ResidueSome white residue.
NotesRequires higher application rate.
NOTE: Some suppliers offer a product combining Potassium Chloride with Magnesium Chloride. Some companies claim their combination product “ensures a fast acting melt with long term performance”
Sodium Chloride – Rock Salt
Effective temperatureDown to 20°F
ConcreteIncreases the number of freeze-thaw cycles, which can damage concrete from freeze-induced expansion. Doesn’t attack concrete chemically.
VegetationSodium is harmful to vegetation. Most commonly used de-icer because of its lower cost. Loses its effectiveness below freezing temps.
ResidueLeaves a white powdery residue.
NotesMixed with calcium chloride to improve low-temp performance.
Urea – Nitrogen fertilizer
Effective temperatureDown to 15°F
ConcreteIncreases the number of freeze-thaw cycles, which can damage concrete from freeze-induced expansion. Doesn’t attack concrete chemically.
VegetationOne of the safer de-icers around vegetation. Considered environmentally safe.
ResidueSome white residue.
NotesLess corrosive to metals and rebar since it doesn’t contain chloride. Requires higher application rate.

MORE: How to use a Snowblower