If you live in a mountainous or northern climate, you have likely seen trucks in the winter spreading road salt and sand on the roads, to prevent and keep them from icing over. This road salt and sand mix have a dual purpose. First, road salt is designed to melt the layer of ice preventing cars and people from slipping. Once the ice has melted, the sand provides traction and grip ensuring that foot traffic and cars can navigate the road safely. While road salt is great it does have several disadvantages when compared to calcium chloride. Below we will describe why you should use calcium chloride on roads, and the best methods and practices that you should follow to ensure that your driveways and roads are safe.
Sodium chloride is usually the salt used on roads.
There are many solutions for applying ice melt or deicers to the roads, most municipalities, however, will resort to the cheapest and most convenient option available: sodium chloride or rock salt. This is not ideal, as sodium chloride is notoriously corrosive, eroding both concrete, asphalt, and polluting the nearby soil, lakes, and streams with the salt runoff. While some municipalities have chosen to use calcium chloride for their deicing auctions, many still resorts to what is the easiest to apply.
The corrosive power of rock salt and its impact on the environment.
Often when faced with a severe ice storm, our first instinct is to get rid of the ice and prevent a further refreeze. Rarely do we think about the consequences or what happens once the ice is melted. Sodium chloride negatively impacts all metallic surfaces, causing corrosion of rebar (concrete reinforcement), car components, and railings on fences and gates. Of all the ice melt options available, sodium chloride is by far the worst culprit, causing irreparable damage. Magnesium chloride and calcium chloride, on the other hand, provide corrosion protection due to the lower levels of chloride and sodium present in the deicer.
Effective temperature varies drastically between all ice melt products.
As we discussed in a number of our other articles, all ice melting products have a different effective temperature range, the temperature at which the respective compound no longer melts ice. This range will determine when the product would lose its deicing ability and refreeze. As a general rule of thumb, the lower the temperature outside, the lower the effective temperature of the ice melt should be. Sodium chloride, or rock salt, will only work up to about 32 degrees Fahrenheit (or just above the freezing point of water.) Magnesium chloride will work up to about 0 degrees Fahrenheit, (-18℃). Calcium chloride offers the most robust effective temperature range, working down to below -25 degrees Fahrenheit (-32℃). If you live in an area where the temperature often plunges to below 0℉, or if you want to simply avoid multiple applications of the deicer, calcium chloride would be the recommended choice for the use of roads.