Every year when winter rolls around the avid skiers are jumping for joy and the average joe is grumbling about snow and ice removal. To the average joe—we don’t blame you one bit! Getting that old shovel out usually means sore shoulders and an aching back. It is not uncommon to rely on ice melting granules to help bust through thick ice buildup. However, with so many chemical compounds available, you might be scratching your head as to which ice melt is best for your concrete. Calcium chloride, magnesium chloride, potassium chloride and calcium magnesium acetate (CMA)—what’s the difference and why does it matter? Stay tuned and we’ll melt it down for you!
Considerations Before the Winter Season
As with any concrete care, it is always best to plan ahead. Performing a detailed inspection of your concrete areas is advisable before you need to put down ice melting products during the frosty winter months. Locating and repairing any broken or crumbling areas is strongly encouraged due to the physical and chemical composition of commercial ice melting agents. The de-icing granules are hard and coarse—this can cause more damage to vulnerable areas of concrete when ground-in by foot traffic and vehicles. For more on fixing crumbling concrete see our latest blog. A small fix before winter is always preferable to a larger one after the fact. You’ll thank us later.
The Difference in Chlorides
There are a wide variety of ice-melting compounds on the market today, and they all have their place within the parameters of their intended use. One key element to consider is how low the temperature will drop. The availability of moisture on the top layer of ice is an imperative factor that determines the effectiveness of the product. The colder it is, the less moisture is available. “Hygroscopic” ice melting agents work by attracting moisture and absorbing it into the granules. This process is known as “exothermic” and it creates heat when the salt and moisture bond together—thus melting the ice. Take a look below at the most common de-icers on the market.
- Calcium Chloride: This is widely considered a very effective agent or product to melt ice. It has the lowest temperature ranking (-25° F) which makes it preferable to use in severely cold conditions. This hygroscopic agent uses an exothermic process to create heat and liquify solid ice. One word of caution: calcium chloride can be corrosive to non-protected metals and greenery such as plants and lawns. Being mindful of the application precautions for this product is recommended.
- Magnesium Chloride: This agent also works well to melt ice, and its hygroscopic process is very similar to calcium chloride. However, due to its makeup of over 53% water, it is more dilute than other options. This means that more is needed to produce the same results as calcium chloride. Its lowest effective temperature rating is 0° F. While magnesium chloride is generally available in the United States, peak seasons demand import from various European and middle-eastern countries. This can cause prices to rise during the winter months. It has similar corrosive risks to calcium chloride and potassium chloride.
- Potassium Chloride: Due to its much higher temperature rating (+25° F), this product is not considered an optimal choice for ice melting. It also melts slower, yielding less melt volume overall. Like the other chlorides, it does pose moderate corrosion risks to metals and may have a negative effect on plants, trees and grass.
- Calcium Magnesium Acetate (CMA): Much like the potassium chloride, this agent has a higher temperature rating (+20° F) and a lower ice penetration measurement. This makes it a less than optimal choice when it comes to melting ice. However, it does have a higher environmental rating due to its organic content, but its toxicity levels can still pose a risk to aquatic life by elevating the demand for biological oxygen.
Calcium chloride and magnesium chloride appear to be the superior products when it comes to quickly melting ice. While there is potential corrosion risk with all chloride compounds, adhering to the application instructions and precautions will provide the best results for your concrete and surrounding areas. A high-grade and well-maintained concrete should withstand any corrosive properties produced by these agents. As mentioned above, removing any leftover granules once the ice has melted is a best practice tip to maintaining your concrete throughout the winter season.