The Kinds of Walkway Salt

The Chemical Reaction

• In general, walkway salt decreases snow's freezing point. After salt application, its molecules dissolve into the fine, upper layer housing a thin water film. As this occurs, heat is generated from the salt and water molecules' movement, or vibration, against one another. The salt slowly dissolves through the entire snow layer as it lowers the freezing point through its chemical reactions. Eventually, the driveway or walkway will appear, remaining snow and ice-free, as long as the salt covers it.

Sodium Chloride Salt

• The most common rock salt for walkways is sodium chloride. This type of salt melts snow down to a limit of 15 degrees Fahrenheit, but it won't create a chemical reaction with the snow if temperatures fall below that. Consumers should beware of sodium chloride's other limitations, including its incompatibility with metal and concrete; if applied to those surfaces, it creates a corrosive chemical reaction that can damage them. Nearby plant life can be possibly injured from accidental salting as well. Additionally, the chloride ions released during the chemical reaction with the snow aren't eco-friendly. As a result, consumers should use this type of rock salt sparingly.

Magnesium Chloride Salt

• Magnesium chloride functions the same as sodium chloride, but works down to 0 degrees Fahrenheit. This is especially helpful in the bitterly cold regions of the world. Magnesium chloride offers more benefits than its more common sodium chloride relative. Plant life and concrete are safer with this rock salt type. In addition, fewer chloride ions are emitted from the chemical reactions, making this salt better for the environment.

Potassium Chloride Salt

• Potassium chloride shares the negative aspects of sodium chloride, damaging concrete and plant life. However, it differs in its temperature value, only melting snow down to 20 degrees Fahrenheit.

Calcium Chloride Salt

• Calcium chloride is the strongest rock salt type available. This salt melts snow down to an outside temperature of minus 20 degrees Fahrenheit. However, this strong salt corrodes concrete and irritates the skin.