Using Salt to Melt Ice

Cars on a road with snow.

Using salt to melt ice is a popular practice and may have several advantages. However, before you start using salt to melt ice, you need to consider the disadvantages of salt as well and find out if you have other alternative deicers.

Using Salt to Melt Ice

Salt is an inexpensive method to reduce the ice from various areas such as roads, driveways, stairs, or lawns. Ice forms when there is rain or snow and the temperatures fall below 0 degrees Celsius or 32 degrees Fahrenheit. Adding salt to ice will lead to a lower melting/freezing point. The modified melting/freezing point will depend on the composition of the salt used and the concentration of the solution used. For instance, a solution that contains 10% sodium chloride will freeze at about 6 degrees Celsius or 20 degrees Fahrenheit. There are several types of salts available, the most well-known being sodium chloride.

Disadvantages of Salt

Salt may have corrosive properties and may destroy concrete surfaces if applied on a regular basis. In addition, salt may accumulate on the surfaces it is applied and will lead to a condition known as efflorescence. Even if efflorescence is considered mainly a visual problem, in time, it may cause spalling of the surface and eventually a crumbling of the structure. To prevent efflorescence, you may apply a hydrophobic sealer on bricks or concrete surfaces. The sealer will penetrate into the material and will prevent the gathering of salt.

How to Use Salt to Melt Ice

When you use salt to melt ice, it’s best to use it in liquid form. However, salt may also be applied in solid form on ice, but it will be less effective. Spread the salt evenly on the surface of the ice and allow it a few minutes to set in. Depending on the thickness of the ice, you may have to wait a few minutes to a few hours for the ice to melt. It is also important to remove the ice or snow from the area using a shovel. Salt alone will not melt all the ice when it is very thick.

Salts Used as Deicers

In addition to rock salt, also known as sodium chloride, there are also other salts that are used as deicers:

  • Calcium chloride is considered a safer chemical and will work at extreme temperatures (e.g. below 0 degrees Fahrenheit, or the temperature when the rock saltwater freezes).
  • Potassium chloride, a metal halide salt, may be used at very low temperatures and will not cause any damage to vegetation, as it is an ingredient that is used in fertilizers, however, it is an expensive deicer.

Alternative Deicers

Some alternatives for salt include:

  • Calcium Magnesium Acetate or CMA, which is safe when applied on soil or vegetation, will not cause corrosion but will not work if temperatures fall below 0 degrees Fahrenheit.
  • Sand, which will not actually melt the ice (unless it is warm), but may be used to facilitate traction. If the sand is warmed up by the sun, it may start melting the ice. Sand is typically used in conjunction with salts on roads.