Although we have not had much for snow here in Kennebunkport, thanks El Nino, freezing conditions and ice control has still been an issue this winter for homeowners and contractors alike. I am often asked by my clients, friends and family, “What is the best ice melter to use?” The first thing that comes to my mind is, what type of surface will the product be applied to? When you have a new stone driveway or walkway, the mere thought of having to lay harsh chemicals on it is difficult. The con being visual and structural damage and the pro outweighing the con is of course, safety. Things to consider when choosing what’s best for you are the type of stone, pets, traffic flow, surrounding plants, and environmental impact.
Remember, for whatever type of ice melt you choose, application is important. Before laying any deicing agent, remove all the snow you can. Spreading a thin, even layer is best. Excessive application is what damages stone most when using any type of melting agent, even the most gentle. Avoid spreading it near plants or grass. In the Spring, melting agents are still there and if they get in your turf or garden beds, it can easily kill anything meant to be green. Now, for the extra step… After the agent has softened and melted the ice, remove it! Whenever possible, use a nice plastic (never metal) shovel to remove this broken up ice and the deicer with it. Why leave the chemical to sit and do more damage when it’s already done the hard part? Remember, dispose of the ice and deicer carefully… no where near anything meant to be green.
Now, for the tough part, which ice melting product is best for you? I have my favorites, but there are options of course so let’s discuss them.
Rock Salt (sodium chloride): This is the among the cheapest products you’ll find that actually melts the ice, but it’s also among the harshest things you can apply for both your hardscape and softscape. Be very aware of projected temperatures if you choose to use this. It can be safe on pavers and natural stones when used in temperatures at or above 15 degrees Fahrenheit. At any temperature lower, rock salt begins to become ineffective. Also when melting and refreezing is a concern, it is not best for pavers and natural stone because if the melted solution enters the porous stone and refreezes, it is at risk for spalling and cracking. Sodium chloride is bad for softscapes, because when it dissolves, it can burn the grass and shallow roots of trees, shrubs and perennials.
Calcium Chloride: I use this on my paver driveway and walkways. Most professionals do. This product is extremely fast acting. It begins melting ice on contact. Calcium Chloride is available at any hardware store, I’ve even seen it for sale at the supermarket. With the primary component being calcium, plants can actually benefit from a FEW applications. If overapplied, it then becomes dangerous to plants so be careful. This product works at the lowest temperature range, down to -25 degrees, and almost completely eliminates the chances of refreezing! These characteristics make it one of the best products to use on concrete and natural stone. The downside to this product is the cost. It is more expensive at double the cost of Rock Salt. It can also leave a messy white residue that can be difficult but not impossible to clean up.
Magnesium Chloride: These premium de-icers are specifically engineered to minimize tracking which means the product will remain on your walkway instead of coming indoors with foot traffic. Magnesium Chloride is effective in temperatures as low as -15 degrees and it significantly reduces the risk of refreezing. This product is preferred by gardeners and pet owners and is considered to be the most environmentally friendly Chloride based melter.
Calcium Magnesium Acetate: This alternative Calcium derivative combines Dolomitic Limestone and Acetic Acid in an environmentally friendly formula that is said to have no corrosive properties at all. Because it contains no Chlorides, this product can be safely used on wood. Most of the other ice melters advise against using on wood surfaces. Although this de-icer is safest for children, pets and the environment, it’s extremely expensive and difficult to find. Also if the temperature is below 0 degrees, this product does not work well at all.
Lawn Fertilizer: In a pinch, I’ve heard you can use lawn fertilizer as a de-icer and traction aid, especially if the product contains high levels of Nitrogen. As the product slowly dissolves, the Nitrogen will melt the ice. ‘Slowly’ is the key word here; this would not be a fast acting ice melt. I wouldn’t use this more than once or twice a winter though, because too much nitrogen can burn your lawn. I’ve never tried this method myself. It might just be one of those old Mainer Engineering stories, but I thought it was worth a mention, as many gardeners have a left over bag of fertilizer in the garage.