Every winter, homeowners in Alberta face the dilemma of how to rid their driveways and walkways of snow and ice build-up without doing any damage in the process. Rock salt and other de-icers are typically used to melt down snow and ice, while shoveling may still be needed to remove loosened but slow-melting "tough spots." Yet, most concrete drives, walkways and stairs can suffer harm from the use of de-icing salts.
Salt Damage to Concrete Driveways
Concrete is a highly durable driveway and walkway material that withstands the pressure of even extremely weighty vehicles rolling over it. However, something as seemingly weak as salt can do significant damage to concrete.
When salt crystals make their way into the concrete through its surface pores, they then attract water, increasing the water-saturation of the concrete by as much as 10%. Additionally, if run-off from ice and snow melted by de-icing salts is not quickly shed off your driveway, it will puddle and seep inside the concrete, increasing the water-saturation further. Once temperatures drop below the freezing point, the water inside your concrete will expand and cause small cracks and fissures as well as surface spalling. A winter with numerous freeze-thaw cycles like we experience in many parts of Alberta can do serious damage to a driveway with excess water content.
If you have just had concrete poured before winter, it is especially critical that it was installed correctly. At least 30 days should be allowed for the new pavement to thoroughly dry out before winter sets in. Concrete with additional water added to it or to its surface during construction will be especially vulnerable to salt damage during winter.
Non-Salt Driveway De-icing Solutions
Aside from just letting the snow accumulate or shoveling/chipping off the ice and snow as best you can, there are four other solutions to clearing off your driveway in winter that do not involve salt.
Sand: It is possible to only use sand on your driveway and walkways. This will not melt the snow/ice, but it will provide extra traction. Mixing sand and salt is a compromise solution that is also popular. If conditions are too slippery, however, sand will not be a safe alternative.
Heated driveways: Installing electric heating coils under an asphalt driveway or hydronic (waterantifreeze circulating) plastic tubing in a poured concrete driveway can effectively melt surface snow/ice. You will have control over temperature settings and can heat only a portion (even just tire lanes) of the driveway if wished. A heated driveway will require an initial investment of at least several thousand dollars and will increase utility bills during the winter season but will last for many years to come.
Snow-melting mats: While snow melting mats are frequently used on outdoor walkways, stairways, and entry areas, you can also turn your driveway into a heated snow melting powerhouse with heated driveway mats. These mats, consisting of a powerful heating element sandwiched between two layers of rubber, can melt several inches of snow in only an hour or two. They are slip-resistant, do not allow melt-off to refreeze, utilize your normal power outlets, and can be easily taken up and stored for next year. Like heated driveways, these snow-melting mats require a large up-front investment and increased utility bills during the winter season.
Rubber Paving: Having a poured-in-place rubber surface installed on your drive as well as walkways and stairs provides the homeowner with a surface that ice does not stick to and that black ice cannot form on. This allows for a safer, slip-resistant surface to walk on and for ease of shoveling. A poured-in-place rubber surface is slightly porous, so snow and ice are not able to stick to the surface. When water on the surface of your drive and walkways freezes, it expands, displacing the air underneath and creating a vacuum to the surface below. Because the poured-in-place rubber surface is porous, that vacuum cannot be created making it easy to simply push the packed snow and ice off without having to chip away at the build up of ice. The poured-in-place rubber surface is durable, long-lasting and environmentally friendly. It can be poured over top of existing damaged concrete or asphalt, making it a less expensive alternative to having the concrete removed and re-poured.
While salt is the most used and less expensive de-icing method, it is also a method that does major damage to concrete and asphalt driveways and walkways each and every year, resulting in costly repairs later on. It is also the least environmentally friendly option. Finding alternative ways to rid your driveway of ice and snow will minimize your salt use and extend the life of your concrete and asphalt surfaces for years to come.
~ Melanie Kehler, Urban Rubber Paving Inc.