Winter inevitably brings with it the danger of encountering black ice as you drive out on the public highways, and the last thing you need is for black ice to "follow you home" and make pulling into/out of or stepping on your own driveway a danger-fraught act.
Black ice forms on pavements whenever snow melt-off refreezes in extraordinarily thin sheets over the surface. Winter's ordinary freeze-thaw cycle can cause this to happen, but shoveling your drive can also aid its formation if done at the wrong time of day. Removing snow in the morning gives the sun a chance to work on the pavement, but removing it later in the day might give black ice a chance to form. Driving or walking on your driveway without removing the snow first can also aid black ice formation by compacting the snow and pushing ice crystals into the pavement's porous surface.
Despite your best efforts to prevent it, black ice may still become a problem on your driveway, especially if your driveway is well shaded and you live in a snow-prone area of the country.
Below, we mention three approaches to ridding your driveway of black ice and keeping it from making a reappearance:
Mechanical and Chemical Removal
Many times, the sun will loosen up black ice for you (if not melt it completely away), and all that need be done is to scoop it up with a snow shovel or chip at it with an ice pick. Great care must be exercised, however, not to damage your pavement, and all black ice removal will not be this simple.
Rock salt (sodium chloride) is the most commonly used deicer on home pavements, but it only melts ice effectively down to 15º F (-9.44° C). For lower-temperature melting, you can use calcium chloride instead, which melts effectively to around -10º F (-23.33° C).
Finally, to prevent ice from forming to begin with, salt brine can be applied to your driveway, particularly just before a major storm to keep the snow from sticking. A water-salt mixture that is 23% sodium chloride is considered by many to be the ideal ratio and can be effective down to -5º F (-20.56° C).
There are some major drawbacks to deicers, however. They can shorten the lifespan of your concrete/asphalt, harm plant life along the driveway's edge, and seep into local ground water supplies, hurting the environment.
Installing a Heated Driveway
On driveways that struggle with black ice every single winter, it may be worthwhile to install a heated driveway system that will effortlessly melt it away. Either the whole drive, a major section of it, or only the tire lanes can be heated, and controls can be either manual or automatic. Automatic controls can be set to respond to low temperatures or made to follow a pre-set daily/weekly schedule.
There are two types of heated driveway to choose between: hydronic and electric. Hydronic involves pumping a heated water-antifreeze solution through plastic tubing installed below the pavement (which is typically concrete). An electric coil heated driveway uses electricity from an ordinary outlet to heat metal rods that are integrated into your driveway. (Electric systems are more often used on asphalt drives.)
The convenience of heated driveways is unquestionable, but they also represent a significant cost. Normally, you will have to tear out your old pavement and replace it in order to install a heated driveway, which comes out to an average expense of around $8,000 (approximately $10,752 CAD). Overall, hydronic systems cost more to install, while electric heated driveways cost more to operate.
A much more portable snow-melt system that requires much less investment than a heated driveway and still avoids the damage that deicers can do is found in snow-melting mats.
Heated driveway mats have the strength to withstand the weight of a vehicle and can be driven on. The slip-resistant rubber with a central heating element is capable of melting several inches of snow per hour. Snow-melting mats also maintain an ice/snow free area that disallows melt-off from refreezing into black ice.
Black ice is a very real wintertime danger in many parts of the U.S., and learning how to best prevent and remove it will help your home (and your driveway) be both safer and more convenient to use.
During the winter months, safe passage to and from your home isn’t just important, it’s crucial. Walking over snow-covered surfaces anywhere can be challenging and dangerous, but when you add in the element of stairs and gravity, and/or highly trafficked areas such as walkways, the risk for accidental falls increases significantly.
In fact, ice and snow are the leading causes of slip-and-fall accidents, and these accidents are the primary cause of spine and back injuries in the United States. Aside from preventing any potentially life-altering injuries, the peace of mind that comes from knowing that you can walk safely in and out of your home is well worth the effort of removing ice from steps and walkways.
While you may have had the best of intentions to keep on top of your snow removal efforts, it can accumulate and quickly turn into a dangerous icy safety hazard. Ice can also potentially cause damage to walkways and stairs when freeze-thaw cycles result in cracking and spalling of concrete surfaces. Once the ice has formed it needs to be addressed as soon as possible, as walking on snow that’s accumulated on top of it can contribute to the formation of black ice, literally adding another layer of risk to an already dangerous situation.
There are a few approaches to de-icing steps and walkways, and they vary in the degree of labor and maintenance required. We’ll begin with more labor-intensive strategies and conclude with the easiest, most efficient approach.
Physically removing ice is best done when it hasn’t become too thick, however shoveling isn’t recommended as an initial approach because it can contribute to black ice formation if done at the wrong time of day, as well as result in damage to underlying surfaces. Removing accumulated ice requires either loosening it first with hot water and or breaking it up with a pick. Once ice becomes slush it can then be scooped away with a shovel.
Going this route involves being out in cold temperatures, risking injury due to slipping or temperature-related health hazards such as hypothermia, and having to “put your back into it” to get results. Depending on the size of the area you’re addressing, this could also be a time-consuming way to go.
De-icing products are in common use and there is a variety of options to choose from.
Rock salt is one of the most commonly used materials for de-icing. It’s fairly inexpensive and does its job when it comes to melting ice. Unfortunately, using it comes with several problems. These include:
- Damage to landscaping and plants from runoff
- Damage to concrete
- Health risks to pets
- Health risks to people
There are several options for chemical de-icers, including calcium, magnesium and potassium chlorides; urea; calcium-magnesium acetate, and liquid potassium-acetate. While these are a better alternative to rock salt, they vary regarding their effects on the immediate environment and their efficiency for melting ice.
Alfalfa meal, coffee grounds, and sugar beet juice are three examples of “green” methods of de-icing. While these options definitely won’t harm your plants and landscaping and might even benefit them, they do run the risk of being a mess to deal with once the ice has melted, including staining and pest-attracting residue.
While effective, all of these de-icing methods have their drawbacks. Specifically, they all need to be scattered, which can be challenging during cold weather particularly if there’s a large area to be covered. As well, they require maintenance and periodic re-dispersal and may present a nuisance or even potential damage to your home.
Heated Stair and Outdoor Mats
This option for de-icing is by far the easiest and most efficient, and these mats come in a variety of sizes including some designed specifically for stairs. Heated mats have the following benefits:
- After plugging them in and putting them down, no further setup or maintenance is required. They can be used with automated snow or temperature sensing controllers to turn the mats on, or can be connected to an outlet wired to an indoor light switch for an easy “on and off” from inside your home.
- They’re extremely durable and designed to remain out-of-doors all winter long.
- These mats have treads, providing increased safety on walking surfaces.
- They’re energy efficient and cost about $1 per day to run.
- This is an environmentally sound and generally safe option. There won’t be any lasting effects on surrounding plants or water sources, harm to pets, or dangers to the people using them.
If you live in a cold climate, ice and snow are inevitable winter hazards. The best method for eliminating them is the one that lets you “set and forget” so you can be sure that the areas around your home will be hazard-free.