It won't be long before we exchange the blue skies and brilliant landscape of fall, and the balmy warm days and cool nights, for the frigid blast of winter. While the white expanse of snow is lovely to look at, an accumulation of the stuff on your walkway and in your driveway can be far from appealing. You don't want to risk a broken leg-or a visitor with a broken leg. So you need to remove the snow and use a deicer.
The safest deicing compound for the environment, for your lawn, and for concrete is magnesium chloride. It is effective to temperatures and low as 13 degrees Fahrenheit below zero. This makes it ideal for a home in northern regions that get a lot of snow and cold weather. Magnesium chloride is also less corrosive to metal such as tin, steel and aluminum. It is also far less toxic to animals.
To be effective, ice melters need to reach the concrete surface. Once on the surface, they begin to separate the ice from the concrete, allowing air and water to flow underneath and generating heat to melt the rest. For best effect, deicing and ice melting compounds should be applied before snowfall starts or ice forms.
The lower damage and toxicity are primarily because magnesium chloride contains less chloride than other compounds used for deicing.
Studies by the National Research Council’s Highway Research Program show that magnesium chloride is 63 times less damaging to concrete than common rock salt, and 26 times less damaging than calcium chloride.
It’s a good idea to paint any metal that will come into contact with deicer, such as the steel bars or mesh used in concrete, and posts used for porch railings.
Magnesium chloride is less toxic to plants and animals, including your pets and your lawn and spring bulbs you may have planted. The runoff is less likely to contaminate ground water and streams.
While sodium and calcium chloride will leave a white residue on your floors and carpets if tracked into the house, magnesium chloride will not.
Fresh concrete poured late in the fall can be hurt by freezing and thawing, and by use of deicing salts. While magnesium chloride is kinder to concrete, it still can cause some damage to fresh concrete. Concrete needs to be cured at or above 50 degrees for at least 7 days after it is poured. After that, it needs to dry for at least 30 days before being exposed to freezing and thawing, and to deicing salts.
While magnesium chloride causes less harm to metals on a one-time application, it can corrode them over time. It can also cause damage to electrical systems on repeated exposure. Used with care and good sense, magnesium chloride can provide a safer walkway and reduce harm to plants, animals, the environment, and your concrete.
Other possible deicing salts are rock salt (sodium chloride), calcium chloride, and potassium chloride.
in areas where the temperature goes below -13, consider calcium chloride, which is effective to -25 degrees Fahrenheit. It is less damaging to both plants and metal than sodium chloride.
Whichever type of deicer you choose, it's a good idea to purchase your supplies before winter. Be prepared for that first snowfall and all the others that will follow.
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