We want to avoid icy road conditions at all costs. The safety of our commute and the commute of our loved ones plague our thoughts when frosty weather is ready to sweep through the streets. There is a sense of safety and reassurance that tomorrow’s commute will be dry and clear when we see the flashing lights of a snow plow or hear the shower of de-icing salt being scattered on the road and sidewalks. Us regular folk never pay attention to the science behind freezing temperatures and the effectiveness of road salt. So, what happens when the temperature severely drops, is salt enough? Understanding de-icing salt vs. minus degree temperature is quite simple. Perhaps this information can help you prepare for the winter ahead.

Freezing temperatures

There are two main determining factors that contribute to ice melting action, amount and temperature. The first factor, the effectiveness of de-icing salt, is determined by the amount of ice that needs to be melted and cleared. Secondly, as the temperature continues to lower, the rate at which salt melts the ice begins to slow down. Water freezes at 0°C, and saltwater freezes at -18°C. Any degree lower, and other de-icing solutions will be put to work. More salt is needed, the lower the temperature, and additives such as sand or chloride will be combined to assist melting and ice prevention.

 0°C water freezes 

-9°C salt begins to slow down its effectiveness

-18°C saltwater freezes 

-30°C calcium chloride is still effective 

Anything lower than -30°C… just stay home, just kidding. Other additive solutions will be combined to prevent icy road conditions.  

Solutions and Science

Depending on the temperature, there are solutions put into practice to ensure our paved roads and sidewalks’ safety. Freezing point depression, salt actually does not melt ice or snow. It lowers the freezing point of water. Therefore, inhibiting ice formation. Salt is cost-effective, readily available, can be stored for future use, and is manageable to work with. A perfect solution as the temperature drops below 0°C and perhaps even before we hit the lower negatives.

Brine is a concentrated liquid solution of salt, water, and at times magnesium chloride. This solution is used as a pre-wetting agent and can spread into cracks and crevices where rock salt can not reach. Therefore, allowing the solution to work immediately, speeding up the chemical reaction process, and adhering to paved surfaces more efficiently.

Calcium chloride creates heat through a chemical reaction, further enhancing the salts melting action. Agriculture solutions, white beet juice, cultivated mainly for its sweetness, is also used to assists during cold weather conditions. Toronto has adopted this solution. The sugar increases the de-icing salt’s effectiveness. The sweet juice will allow the salt to adhere to the ground, therefore preventing ice patches. They say it has a sweet smell, how festive! Although the scent may not be noticeable due to the congestion of traffic. It is perfect when added to brining solutions and useful for -32°C temperatures. Sand is also used at freezing temperatures when salt is just not enough, sand is added to create traction.

Unsure of which solution to use in minus degree weather, call on FSI Landscape Supply.