The Best Ice Melt & Rock Salt in 2021
I hope you agree with me that a frozen sidewalk, stairs, or driveway can be a death trap.
You may clear it with a trusty old snow shovel or a snow thrower, but the dangers of the ice underneath need be taken seriously. This becomes even truer the older and less flexible you get. It is important to talk about removing ice not only effectively but also safely in case you have pets that may come in contact with ice melting materials.
1. What is ice melt and is it for me?
Ice melt comes in several varieties and while it has some drawbacks, it is more effective at removing ice than rock salt is. It, too, is a type of salt and generally comprised of potassium chloride, calcium chloride, sodium chloride, or magnesium chloride. Note that sodium chloride is ordinary cooking salt, so we are talking about a mixture of different salts than the kind you are commonly used to. Of these ingredients, calcium chloride is the most effective one at its job. Once the material is applied to pretty much any surface, it starts to work immediately.
Why does ice melt work in the first place? It is always helpful to know why something works, especially if it is simple. When you combine water and salt, the freezing point of water is reduced, meaning it will freeze at a lower temperature than pure water. By adding salt to ice, its temperature is not low enough anymore for it to be frozen – thus it melts. Some products work all the way down to -40F and it works quickly.
2. What is rock salt and is it for me?
Rock salt is the de-icing workhorse used throughout the winter months. Since it is cheaper than its competitor, it gets used by salt spreading vehicles all over.
Chemically, rock salt is sodium chloride in its mineral form and works the same way ice melt does since both of them are salts. By adding it to water, a solution called a brine is formed, whose freezing temperature is lower than that of pure water ice. Hence even a cold winter day is not cold enough to cause brine to stay frozen. So what’s different about it? As the name suggests, rock salt also contains bits of gravel, such as grit, and to help both people and vehicles to gain more traction on roadways, driveways, and so on.
Due to its lower price point, this solution seems to be the better option on first sight. While this is true for the public spreading vehicles and other commercial situations where large quantities are used, it is decidedly worse for residential usage. Not only do you need a lot more of it compared to the other option, but it is also much less effective. By having to use more, it can turn out to be more expensive in the long run.
Apart from electric snow blowers, of the products we use ourselves (see the table at the top of the page) works all the way down to -40F, while rock salt only works into the realm of +20F. So on a particularly cold morning, your rock salt may go on strike and you’d wish you had ice melt for your driveway or sidewalk.