Ask any company that sells de-icer products, and they’ll tell you rock salt and ice melt are two of the most popular products for commercial application. At Nina Deicer, our staff is often asked, “is rock salt the same as ice melt?”.
While both are used to melt through snow and ice on sidewalks, parking lots, and other surfaces, they’re different products with distinct chemical compositions and freezing point capabilities.
Let’s discuss their differences.
Calcium Chloride & Sodium Chloride
Rock salt, also known as sodium chloride, is the very same product as table salt. The primary difference is in the way that it's grounded. Rock salt is larger particles whereas common table salt is more granular and retains its crystalline structure.
Calcium chloride (ice melt) is also a type of salt in its own right. It’s not one that tastes good, nor does it have any of the other culinary benefits of our beloved sodium chloride. However, it doesn’t have the same environmental impact as rock salt. A benefit of calcium chloride is it’s regarded as safer for pets in case of ingestion, and it’s less corrosive to vehicles and concrete.
Both rock salt and ice melt are de-icing and anti-icing agent. The big differences between the two are their chemical composition and the effective temperature at which melting snow and ice. Calcium chloride melts snow and ice at lower temperatures than sodium chloride.
Ice Melt vs. Rock Salt: How Do They Compare?
This is how ice melt works in comparison to rock salt in terms of price, ice formation, potential environmental damage, and safety:
Rock salt is a cheaper method to melt ice. It costs anywhere from $4.50 to $9.50 for a 50-pound bag, on average, depending on which state you’re in. And, if you’re willing to buy in bulk to stock up for winter weather, you might even be able to buy it for a low cost of $3.95 per 50-pound bag.
Ice melt generally costs between $6 to $12 per 50-pound bag. Ice melt is also available in bulk, but it’s certainly not as cost-effective as rock salt.
2. Effective Temperature
A big difference between rock salt and ice melt is that the latter melts ice at significantly lower temperatures than the former. Once rock salt is applied, it begins to melt ice immediately, assuming the temperature is above 0 degrees. Yet, in subzero conditions, rock salt is ineffective. Ice melt, on the other hand, can work in temperatures as low as -25ºF, often making it a more ideal option.
3. Parking Lot or Vehicle Damage
Unfortunately, rock salt is highly corrosive and repeated exposure can lead to significant chassis and engine corrosion. It also affects car paint and may cause rust to form underneath the surface, making car metal brittle and flaky.
As for parking lots, rock salt can erode masonry, and other types of stone, including concrete and asphalt. Over time, it causes erosion under the surface, leading to discolored, cracked, and crumbling concrete.
Ice melt is generally safer for cars and concrete, but that doesn’t mean your parking lot is immune to long-term damage. It can erode surfaces, depending on its chemical composition, even though its effects aren’t as extreme or rapid as rock salt.
We recommend repairing damaged concrete before winter weather arrives, so water doesn’t freeze in cracks and push concrete apart. Additionally, you should remove the product from parking lot surfaces once the ice has melted to minimize abrasions and damage.
4. Plant and Animal Safety
Rock salt works well but is potentially harmful to pets, kids, and plants. The cheaper the product, the more damage it does. Rock salt with a calcium chloride chemical mixture is better for your plants but worse for concrete or asphalt. If the area you plan to de-ice is located near plants, you should rather use an eco-friendly, plant-safe alternative.
If ingested by pets, rock salt can cause gastrointestinal disorders, as well as burning and irritation if it gets stuck on their paws. Fish, frogs, and other amphibious creatures may also suffer if rock salt flows into their water supply.
For many, the cost of ice melt is worth it because it’s less harmful to pets, plants, and other animals. Currently, there are a couple of all-natural, salt-free options available on the market.
Just always make sure to read the labels. To be truly pet-friendly, an ice melt should be coated with magnesium chloride.
5. Melting Speed
Rock salt melts ice up to seven degrees lower than the freezing point, about 5ºF. Therefore, the best time to apply it is before snowfall starts. This prevents ice from forming and snow from settling. Because salt has a lower freezing point than water, it reduces the opportunity for water to freeze on treated surfaces.
Some ice melt products that contain calcium chloride work up to - 25ºF, making the product more effective and faster acting than traditional rock salt. When ice melt water granules contact ice or snow, they form a brine solution that’s central to the melting process.
The right time to apply ice melt is before precipitation begins to prevent ice from bonding to the surface. Keep in mind, pre-application can cause the brine to refreeze under a heavy snow pack if shoveling or plowing doesn’t occur within a reasonable time.
So, if you’re wondering when to apply ice melt, we suggest using it only when you are planning to scrape the surface, removing any remaining ice or snow to prevent refreezing. If snowfall amounts to two or more inches, then rather plow and shovel first, and use ice melt to melt ice or hard-packed snow that remains.
What Is the Right Way to Apply Rock Salt or Ice Melt?
Here are some helpful tips when applying rock salt and ice melt products:
- These products are most effective when placed directly on ice and don’t work as well on fresh layers of snow. For this reason, it’s best to clear away snow first.
- Remove as much snow as possible from the surface you wish to treat. Use a plow or snow blower if necessary.
- We recommend applying the material in a thin even layer using a salt spreader. Depending on the surface area, you may want to use a drop spreader or broadcast spreader.
- If you don’t have a spreader, use a cup to sprinkle it evenly over the surface. Always wear gloves as these products can irritate bare skin.
- Lastly, be sure to follow the manufacturer’s instructions on the package.
Rock Salt vs. Ice Melt: Which Is Better for Your Business?
If you’re removing snow around animals and children, then you may want to stick with ice melt even if it costs more and is less effective with pre-existing ice.
Rock Salt vs. Ice Melt: the Bottom Line
As you may have guessed, neither option is a “catch-all” solution for ice prevention/removal. Depending on the temperature or the amount of snow, your strategy for removal will be different.
However, with a better understanding of what rock salt and ice melt are, and how they’re best used, you can create a snow removal strategy of your own. You may even want to invest in both, and use them when applicable.
Still, need help deciding which de-icing products are best? Ninja Deicer is more than happy to advise you about potential options. We stock a large variety of products for all types of applications. Contact us today to find out more or get a quote.
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