Winter is here with a vengeance in many parts of the country right now and the cold weather seems to be bringing more snow every week or two. But with snow melting during the day and freezing during the night, a lot of people are finding that while the snow may be annoying, the ice is what’s really dangerous. Walkways, driveways, sidewalks and outside staircases are all prone to icing over and creating slippery conditions whenever you find moisture mixing with colder temperatures. The right chemical ice melt can make all the difference when it comes to keeping your walkways and driveways safe and ice free.
There are many different ice melts, but they are mostly a combination of the same basic chemicals.
There are several expensive ways to combat icy walkways including using large heated mats or installing special heated sidewalk systems that use either hot water or electrical heating elements to keep them from freezing over.
The cheaper, and much more available option for most people is to use some sort of “ice melt” chemical or spread which, when applied to ice, will lower the freezing point, thus turning it back to water or water vapor and allowing it to dry at least not turn back into slippery ice for some time.
There are advantages and disadvantages to the different types of ice melt on the market. Here’s a quick rundown of the ice melt products you can choose from:
Rock Salt/Halite/Sodium Chloride
This is the most basic and definitely the cheapest of all the chemicals that is used for melting ice from sidewalks and walkways. It’s really just industrial grade salt, very similar to the stuff on your kitchen table. Cheap and readily available, rock salt does have some drawbacks. It is a fairly corrosive chemical and it can damage vegetation in higher amounts. It’s also only useful down to about 15F which is cold, but many parts of the country do get colder.
Calcium Chloride
Another popular but slightly more expensive ice melt product is calcium chloride. When you think of “ice melt pellets” you are probably thinking of a calcium chloride product. Calcium chloride is easier to spread and is effective at a lower temperature than sodium chloride. Calcium chloride works faster than sodium chloride and it actually creates heat when comes in contact with moisture. These pellets generally work so fast you can sometimes hear the ice cracking as you spread it.
Pet Safe/Chlorine-Free/Urea
Ice melt pellets made from urea are usually advertised as being “pet safe” because they won’t agitate pet paws. Pets get sick from ice melt with chloride because it causes them to lick their paws, ingest the chemicals (especially large amounts of sodium) and they get ill. Urea is used in fertilizers, does have some corrosive properties and is often more expensive than sodium chloride or calcium chloride.
Other Chlorides
There are other chloride products such as potassium chloride (potash) and magnesium chloride which each have advantages of their own. Potassium chloride is generally considered to be more environmentally friendly than other chlorides and magnesium chloride can be sprayed down in a liquid form onto surfaces to help prevent ice forming in the first place.
Acetates
Including sodium acetate and calcium magnesium acetate, acetates are environmentally friendly but often more expensive than other ice melt options. Again, they can be used to prevent ice from forming in some instances.
Those are the basic differences that you’ll find in just about any ice melt product on the market. That being said, many ice melt production companies use a combination of the above chemicals as well as a packaging and marketing differences to make their product stand out. Most “heat generating” ice melt products are simply mixtures of calcium chloride and most “pet safe” products are urea. And while many of the above chemicals are advertised as environmentally friendly and non-toxic, you do still want to be careful with them. Many of the chemicals above can also be found in the fertilizer you use on your plants or your lawn. Some ice melt products require more pellets or granules to be applied than others, so read the instructions and use the product sparingly at first, adding more as you see fit.
You’ll also want to understand that most ice melt products themselves can only do minimal damage to concrete patios or walkways on their own. Ice melt products do not generally harm driveways, bricks or cement on their own. You can blame your chipped and potted bricks or concrete on something called the “freezing/thaw cycle” and it’s relatively natural. Here’s how it works:
You have a layer of ice over your brick walkway. You spread down some ice melt of your choice and wait an hour or so. When you return all the ice has been melted into water and that water has seeped into your porous bricks. That night it gets cold and the moisture in your bricks freezes. When water freezes it expands and that’s ultimately what damages your bricks. Each morning you spread more ice melt and each morning it thaws again. The constant thawing, seeping and then refreezing begins to damage the brick and you may begin to see chips flaking off. Over time, this can have a detrimental affect on your walkway. If you find yourself using ice melt products that are corrosive then those chemicals could also seep into your concrete and begin to corrode and damage the metal rebar that’s used to hold your cement together.
Fortunately, there is a relatively simple way to prevent this, and that’s by sealing your concrete properly and then re-sealing it as needed. Another good way to minimize the damaging effects of the freezing/thaw cycle is to clear away any thick slush or slurry that’s left over after applying ice melt. You may then want to reapply some ice melt once you remove as much water as you can.
My personal preference for ice melt? I live in New Jersey where it doesn’t get extremely cold, so I usually stick with calcium chloride for my driveway because it works quickly and it’s relatively cheap. I do tend to use the pet safe stuff on my walkways because I have two cats. Yes, we still walk on the driveway and we have a chance of tracking in some calcium chloride, but I figure most of the calcium chloride on my shoes will end up being lost on the walkway to my front door…
I used to be a little reluctant to use ice melt because of the expense, but now that I have a family I see the wisdom in it. Remember: ice melt only seems expensive until you realize that one slip and fall on an icy walkway could have you in the hospital for weeks. Good luck and stay safe this winter.
Wish I would have found this post last month when the snow was really bad.
Ant