Salt Treatments for a Driveway

Sodium Chloride

• Sodium chloride, or rock salt, is an inexpensive driveway treatment that melts ice at temperatures as low as 18 degrees Fahrenheit. This deicer is the type of salt used for food seasoning. Rock salt is the road treatment of choice in many areas, but it is highly corrosive and can pollute rivers and groundwater. It also burns, stunts or kills plants along a driveway by interfering with water and nutrient absorption. According to the University of Maryland Cooperative Extension, brick, stone and newly poured concrete are especially susceptible to sodium chloride damage.

Calcium Chloride

• According to Mother Earth News, calcium is a relatively expensive deicing option that costs three times as much as sodium chloride. In pellet form, it melts driveway ice at temperatures as low as -25 degrees Fahrenheit and creates heat as it penetrates ice buildup. Liquid calcium chloride is effective at even lower temperatures than pellets. Calcium chloride is less harmful to plants than rock salt, but heavy applications can still injure plants and damage concrete, metal, brick, stone and outdoor carpeting. To protect hands from irritation, wear protective gloves when applying calcium chloride.

Potassium Chloride

• Potassium chloride, which is an ingredient in fertilizers and table salt substitutes, melts ice at 25 degrees Fahrenheit or warmer. It is less harmful to concrete than other salt treatments, but repeated use can still injure plants and pollute water. Potassium chloride will not irritate skin but often leaves a white residue on driveways or indoor carpeting. AskTheBuilder.com notes that this salt is effective at colder temperatures when combined with other salts.

Magnesium Chloride

• Magnesium chloride is a relatively new addition to driveway treatment options. This salt melts ice at -13 degrees Fahrenheit and is less harmful to plants than other driveway treatments. According to AskTheBuilder.com, magnesium chloride can melt through a 1/2-inch layer of ice within 10 minutes and releases 40 percent less chloride pollutants than calcium chloride or sodium chloride. Homeowners will appreciate the fact that magnesium chloride will not create a powdery residue on indoor carpets. Like other salt treatments, this deicer may corrode metal automobile parts.