You’ve heard that deicing salts are not ideal when you need to get ice off your concrete sidewalk, driveway or other surface. Which types are especially unfit for use and which will cause the least damage?
Salt on sidewalk
It’s wise to do research before you learn the hard way, when your concrete cracks and crumbles before its time. Be prepared this winter and learn how to remove ice from concrete effectively, causing the least damage in the process.
How Does Salt Hurt Concrete?
Concrete is one of the strongest building materials, but it also absorbs moisture. When salt is sprinkled on concrete coated in ice, the ice melts and the water permeates the concrete.
If the temperature drops soon after, the water in the top layer of the concrete freezes and expands. This leads to an increase of pressure that can lead to spalling (breakage of the top layer).
Salt makes this issue even worse, since it’s hygroscopic, meaning it attracts water. Concrete covered in deicing salt will have an increased level of moisture saturation, and the damage from the water’s expansion will be more drastic.
Are Any Deicing Chemicals Safe?
Sodium chloride is the most common deicing salt, but not only will it harm concrete, the salt in the runoff can pollute nearby bodies of water. Calcium chloride is even more dangerous than sodium chloride, because its chemical properties can degrade concrete.
Two other modern deicing salts are also offered at many hardware stores, including potassium chloride and magnesium chloride. Potassium chloride only melts above 15 degrees Fahrenheit and is less harmful to the environment and humans, but it can still have a devastating effect on a concrete surface.
Magnesium chloride releases the least amount of chloride and therefore is the least damaging, so it can be used when necessary, but never on concrete that has not completed the curing period.
While you may hear that you can use fertilizer to remove ice from concrete, this usually is not recommended. Many fertilizers contain ammonium nitrate and ammonium sulfate, both of which break down the material.
Which Option Should You Use?
The best way to deal with ice on concrete is to prevent buildup in the first place. Whenever it snows, immediately remove the top layer before it has a chance to freeze into place.
It’s safe to use a snowblower or shovel on your patio, steps or driveway, but make sure you clear away all sticks, leaves and rocks before winter begins to make the snow removal process easier.
Once you have cleared the snow away, spread sand or kitty litter on the areas where you need to reduce the chance of slipping, but be aware that these materials will probably get tracked into your house.
You also can spread gravel or hay on top, but you will have a hefty cleanup job when spring arrives.
Want more advice? Talk to the specialists at Lift-Up Concrete. We can talk to you about the best ways to remove ice from concrete without damaging it.
