Rock Salt vs. Ice Melt: Pros, Cons, and Safety Tips

During winter, walking from the car to the house can be treacherous. Homeowners use rock salt and ice melt to keep walking areas clear of slippery ice and prevent nasty tumbles down the steps or walkways. 

But what's the difference between rock salt vs. ice melt, and is one better than the other? Here’s everything you need to know about magnesium chloride ice melt and rock salt to make the best decision for your home.

Rock Salt vs. Ice Melt: Key Differences

It's time to melt the ice outside your home, but what product do you choose? You have your pick from several product types when melting exterior ice. Rock salt provides traction while breaking down ice, but it takes longer to work and is only effective down to 5 degrees Fahrenheit. Keep in mind that a contract with a local snow removal service can ensure your walkways are shoveled and de-iced without having to brave the winter elements.

On the other hand, ice melt doesn’t provide traction while it works, but it yields results quickly in temperatures as low as -15 degrees Fahrenheit. Each of these product types is great for treating slick areas like icy sidewalks and steps in combination with other snow removal equipment. 

What Is Ice Melt?

The active ingredients in standard ice melt products include sodium chloride, rock salt, calcium chloride, potassium chloride, magnesium chloride, and/or urea, which is also known as carbonyl diamide. These are powerful chemical agents that melt ice effectively, but they can also present some risks to kids and pets. 

Best for: 

• Melting ice in very cold temperatures

• Driveways with low levels of foot traffic

Pros of Ice Melt

You can give yourself an edge by applying the product before the snowstorm or ice begins to melt. The active chemicals in these products make it difficult for snow and ice to stick, which means you will have less to do once the storm passes. One of the main benefits of ice melt is that it provides fast results in very low temperatures, making it possible to leave your home safely during a snow or ice storm.

Ice melts are available in a wide range of chemical compounds, and each reacts differently to common yard materials, like concrete and vegetation. For instance, calcium chloride is perfect for concrete, while sodium chloride and ammonium sulfate damage concrete with repeated use. Read the ingredients list and do some research before settling on a purchase. 

Cons of Ice Melt

Ice melts are powerful but finicky products. The chemicals used to make the ice melt are unsafe for humans to consume or even touch. Protect yourself by wearing long, thick gloves and covering up any exposed skin during the application process. These are powerful chemical agents, so don’t overapply. Follow the instructions to the letter regarding application amounts. Using more ice melt than recommended does not speed up or improve the process in any way. 

While some ice melt products are safer for pets than others, take precautions. If your dog walks on an ice-melt-treated area, wash their paws immediately, as it can cause irritation and chemical burns to skin and paws. Ingestion can lead to gastrointestinal issues, vomiting, diarrhea, and more, according to the American Society for the Prevention of Cruelty to Animals.

What Is Rock Salt?

Rock salt isn't that much different from the salt you find in your spice cabinet. Its chemical name is halite, and it's the unprocessed mineral form of sodium chloride. When you add salt to water, it creates a solution known as brine. Salt melts ice because brine has a lower freezing temperature than plain water, so when it's applied to a frozen surface, the ice begins to melt.

Best for:

• Walkways, pathways, and areas with high foot traffic

• Melting areas with a large square footage

Pros of Rock Salt 

The primary benefits of using rock salt for snow and slippery surfaces is that it’s less expensive than ice melt and provides plenty of traction. That’s why this product is the preferred solution for walkways, steps, and paths that receive heavy foot traffic, ensuring a safe passage.

Rock salt performs miracles, but not without some help. If there are large amounts of snow, the salt struggles to make headway on its own. This is where shoveling comes in. If possible, shovel during the storm to limit accumulation. If the snow is hard already, apply rock salt on the top layer and try shoveling after letting it work for an hour or so.

Cons of Rock Salt

The vast majority of rock salt products stop working when temperatures fall below 15 degrees Fahrenheit. If the temperature drops immediately after a snowfall event, use sand or cat litter to help with traction and save the rock salt for when the temperature rises a bit. 

Rock salt threatens wetlands, creeks, and rivers. High chloride levels can kill fish, bugs, and amphibians, according to the Environmental Protection Agency. If you see crystals on ice or snow after the salt is dry, you used too much. A  pound of rock salt is enough to treat 250 square feet. Sweep remaining granules to reuse, or dispose of them properly. 

As with most ice-melting products, protect yourself by wearing gloves during the application process and by exercising extreme caution as you navigate the frozen tundra of your yard. If you’re uncertain how to do this safely, hire a snow removal company instead.

Rock Salt vs. Ice Melt

Compare these two ice-melting agents to determine which is best for your home.

Application: Tie

When it comes to ice melt vs. rock salt, both are simple to apply to icy surfaces. Don’t forget to wear hand and eye protection when using either of these products, and follow the manufacturer’s instructions for safe application. 

To get the most effective results, don’t wait until your walkway or steps are already iced over. Apply either product when a storm is approaching and again once the snow and ice fall have stopped. 

Application before snowfall means you’ll have less accumulation and less ice buildup after the storm, ensuring you have a safe walking surface before, during, and after winter weather hits.

Effectiveness: Ice Melt

Rock salt will melt ice down to around 5 degrees Fahrenheit, helping provide traction on slippery surfaces. But it doesn’t work in negative temperatures. Ice melt is effective down to -15 degrees Fahrenheit and works faster to melt ice than rock salt.

Cost: Rock Salt

The costs of ice melt and rock salt aren’t wildly different. You can purchase  both options for less than $50 for a 50-pound bag at most home improvement stores. Rock salt generally costs $10 to $20 per 50-pound bag, while ice melt typically costs $15 to $35 per 50-pound bag.

While rock salt might be less expensive, it might require a heavier application to be effective, thus making ice melt a more economical option if you need to de-ice frequently over the winter.

Faster Results: Rock Salt

Rock salt works best above 5 degrees Fahrenheit, which isn’t a problem for most temperature zones. In these conditions, rock salt’s direct chemical interaction tends to be speedier. If you want a walkable surface for your home business faster, rock salt is usually the best option.

Ice melt works a bit slower than rock salt as long as temperatures stay above 5 degrees Fahrenheit. If temperatures fall below that point in especially cold zones, then rock salt stops working and ice melt options will be faster.

Eco-Friendly Options: Ice Melt

If you want to go green for your ice-melting endeavors, which product is best? 

Well, rock salt is simply rock salt. There’s no way to apply it that’s greener or better for the environment.

For broader ice melt options, you can find eco-friendly alternatives that don’t use the same kind of chemical interactions. For example, some use ground beets and beet juice to help melt ice while suspending chloride so it doesn’t cause as much damage. Some skip any kind of sodium component and use pure magnesium chloride. And in mild freezes, even using sand or cinder dust is an option.

Risk to Animals: Tie

Pets that want to play in the snow or take their expected walks can also run into rock salt and ice melt. Rock salt and ice melt gets embedded in pet’s paws, where it can prove irritating and cause burns. Even worse, pets try to lick away the rock salt, which rapidly raises the level of sodium in their blood. This can make pets sick and cause problems like kidney damage.

Ice melts use a number of chemicals with varying effects. More toxic kinds of ice melt can cause vomiting and diarrhea, or more serious problems if pets ingest a large amount of it. Less toxic versions may simply be irritating. Either way, animals should stay away from these substances.

Material Damage Risk: Ice Melt

If you’ve lived by the ocean, you probably know how corrosive salt can be. That’s the same kind of salt used to melt ice, which creates the potential for material damage, too.

Rock salt can be very corrosive, especially when mixed with water and soaked into ground materials. It also encourages a freeze-thaw cycle where melted ice soaks into cracks and then freezes again, expanding those cracks to cause more damage. 

That’s why rock salt often causes long-term damage to concrete, asphalt, and any nearby metal components like landscape lighting frames and deck screws. When it’s kicked up onto vehicles, it can also cause corrosion on cars.

Ice melt’s effects are milder. It can damage cement and concrete, especially cement that’s already been worn down, but poses less of a danger to other materials.

Landscape Risks: Ice Melt

Soil needs a balanced pH and healthy nutrients to support plants (and the creatures that depend on them). Rock salt, especially inexpensive versions, is destructive to this balance. After heavy use, it washes into lawns, flower beds, gardens, and other areas where it can poison plant life. In many cases, users won’t know the extent of the damage until spring.

Ice melts cause significantly less damage to plants, especially the kinds that avoid the use of sodium. They’re a better pick for protecting your landscape.

Legal Issues: Ice Melt

Due to the issues mentioned above, some cities have regulations about how to melt ice. These laws are primarily commercial and public in nature (and subject to change over the years). However, property owners still need to be careful. 

Local environmental laws may ban the use of rock salt on public areas like sidewalks. More commonly, property owners could run into civil suits and other problems if their use of rock salt poisons a neighbor’s plants or pets.

In areas where commercial use of rock salt is banned, local governments typically allow the use of a liquid deicer, a more eco-friendly solution like beet juice and brine, or a more inert substance like sand. These legal issues, plus its landscaping safety, makes ice melt a better bet to avoid legal snafus.