It’s important to keep your driveway and the pavements around your home clear of snow and ice to reduce the risk of slip-and-fall accidents on your property. When winter storms threaten, DIY homeowners have three approaches to snow management from which to choose: chemical agents that clear these hazards away after the storm passes (de-icing), chemical agents that preempt them before a single snowflake falls (anti-icing), and non-chemical alternatives. Below, we take a look at these approaches.
De-icing is key to taming wintery hazards. However, these chemical salts are meant to be spread only on the thin layer or residue that remains after shoveling, snowplowing and/or snowplowing away the bulk of the snow. They cannot do the job of melting all the snow by themselves.
Sodium chloride and calcium chloride are the two main salt options for this de-icing phase, however each option has its own disadvantages.
The most common, most affordable, and most widely available de-icing agent is sodium chloride, more popularly referred to as "rock salt." Rock salt is easy to store and distribute, whether by hand or by a mechanical salt spreader, and effectively melts snow/ice at temperatures as low as 15 to 20 degrees Fahrenheit. Like other de-icers, it works by lowering the freezing point of water, and is effective at relatively mild winter temperatures.
Rock salt has some drawbacks, however. First, it fails when temperatures dip too low. Second, it damages concrete and asphalt by exacerbating the freeze-thaw cycle when temperatures repeatedly fluctuate above and below 20°F. Also, it seeps into the porous surface of concrete and draws water in, which causes further damage when that absorbed water refreezes. And rock salt can migrate into plant beds causing damage to plant life. Nonetheless, rock salt answers the need for an affordable snow/ice melter at relatively high winter temperatures.
Calcium chloride is effective down to about -25°F, making it the better choice at lower temperatures. It works by attracting moisture to itself, even in dry conditions, then dissolving in that moisture and cutting into ice surfaces. It is also an "exothermic" product, meaning that it reacts chemically with water to release heat from within itself. This all translates into faster snow-melting even at very low temperatures.
The drawbacks to calcium chloride are that it costs more than rock salt, it can leave a slippery residue, and it, too, can harm concrete and nearby plant life.
A reasonable strategy for removing snow is to combine these two approaches: use rock salt as your standby de-icer and calcium chloride for colder weather.
Liquid salt brine, of rock salt or another salt, is an anti-icing agent that you can spread just before or just after a snow storm hits. Much of the snow will melt on contact with the brine and it prevents a bond from forming between the pavement and any snow that does accumulate, making shoveling later a much easier job.
Not long ago, New Jersey made headlines by utilizing pickle brine to de-ice its highways, and Wisconsin (characteristically) opted for cheese brine as an alternative to traditional rock salt. While these strategies well-served the purpose down to around six degrees below zero, homeowners will likely find other alternatives to salting their driveways more practical (and free of the pickle/cheesy after-odor).
There are really only two viable alternatives available to homeowners to melt the snow and ice on their driveways and outdoor walkways without resorting to some form of salt: heated driveways and snow-melting mats.
Heated driveways/walkways can be of two types: electric coil and hydronic. The latter works by circulating an antifreeze-water solvent through in-pavement plastic tubing; the former by means of electrically heated metal coils. While heated driveways are a great convenience and a long-term solution, they typically cost thousands of dollars to install, require that you first tear up your existing driveway, and cost hundreds of dollars per year to operate.
The second option is laying down seasonal snow-melting mats, which come in grades appropriate to driveways, walkways, entryways, and more. These mats melt snow at rates of two inches per hour and can keep tire lanes and walking areas snow/ice-free continually. Snow-melt mats cost much less than heated driveways and are 100% portable.
Homeowners can always contract with a snow-removal service or hire a local teenager to clear away snow and ice. But for those who opt to do the job themselves, it’s critical that you use the best de-icing agent for each temperature range and also include anti-icing agents in your “arsenal.” Or, eliminate the use of chemicals all together with a heated driveway or snow-melting mats.