Rock salt is a staple for most winter maintenance
Bitter cold snap lessens salt's effectiveness
Take a look at the chart above, you can see that at a temperature of 30 degrees, one pound of salt will melt 46 pounds of ice. As the temperature drops, salt's effectiveness slows to the point that when you get down near 10 degrees and below, salt hardly works at all.
Calcium chloride is typically the best choice because it melts ice at very low temperatures, all the way down to -25 degrees Fahrenheit, and is a relatively safe choice for lawns and landscapes when applied appropriately.
Tim Mason, operations chief for the northwest region of the Wisconsin Department of Transportation, said once temperatures drop below 15 degrees Fahrenheit, salt becomes nearly ineffective. That's because the chemical makeup does not allow it to melt snow and ice at certain temperatures.
Rock salt is a staple for most winter maintenance deicing programs, but at what temperature does it become ineffective? Salt will “work,” i.e. it will melt ice, all the way down to its eutectic temperature of -6 0F. However, the “practical working temperature” of salt is generally considered to be higher than this.
If the temperature of the roadway is lower than about 15 degrees F (minus 9 C), the salt won't have any effect on the ice. The solid salt simply can't get into the structure of the frozen water to start melting ice. In these cases, the DOT typically spreads sand on top of the solid ice to provide traction.
What is the safest ice melt for concrete? Calcium Magnesium Acetate (CMA) and Sodium Acetate (NAAC) are often considered the finest concrete-safe ice melt solutions available. When applied to concrete, both CMA and sodium acetate are much less corrosive than a number of other ice salts.
0°F (-18°C) and Lower: Road salt completely stops working at extremely low temperatures because the brine will freeze at this point. Other deicing options, like calcium chloride or magnesium chloride, can be used instead.
“Regular rock salt ice melt only works down to 20 degrees, so there's other ice melts that work down to other temperatures. Like your calcium chlorides, your magnesium chlorides will melt ice down to a lower temperature, down to -30 degrees” said Carl Combs of Rocky's Ace hardware in Springfield.
Using ice melt at temperatures lower than its lowest working temperature will not produce results. Some ice melt is effective at temperatures as low as -25 degrees F. Some will only work down to 25 degrees F.
Temperatures near or below freezing (32°F or 0°C)
You don't need to be a meteorologist, but awareness of current and upcoming weather conditions can be your best defense against road icing.
A normal blood sodium level is between 135 and 145 milliequivalents per liter (mEq/L). Hyponatremia occurs when the sodium in your blood falls below 135 mEq/L. Many possible conditions and lifestyle factors can lead to hyponatremia, including: Certain medications.
What Temperature Is Freezing? Water will freeze at 0 degrees Celsius, which is 32 degrees Fahrenheit. Any time the temperature drops below these, liquid water will begin to turn into ice. Water behaves very differently than other liquids.
However, if temperatures are in the 15-25° range and it's daylight, road salt can still work pretty well. Once you see the temperatures fall below 15°, road salt becomes nearly ineffective. That is because the chemical make-up of plain road salt disallows it to melt snow and ice at certain temperatures.
Sometimes, the system fails to use the salt in the brine tank, often because of a blocked brine line, a faulty injector, or a stuck float valve. Many modern water softeners display error codes to indicate specific problems. While helpful, these codes often require troubleshooting or professional interpretation.
In fermentation, salt helps create an environment where beneficial bacteria can thrive, outcompeting harmful pathogens. These beneficial bacteria, like Lactobacillus, are salt-tolerant and can survive in brine, while harmful bacteria are kept at bay by the acidic environment created by fermentation.
Calcium chloride is safe for concrete, but do not use calcium chloride on asphalt. For asphalt, go with magnesium chloride. We recommend Harris Kind Melt Pet-Friendly Ice Melt. It works fast down to -13 degrees Fahrenheit and is safe for concrete, plants, and animals.
Magnesium chloride is a great choice! While magnesium chloride is more expensive than sodium chloride and calcium chloride, it is less likely to damage your concrete or your lawn. This type of salt only works in temperatures down to 0° F, which is better than sodium chloride but not quite as good as calcium chloride.
Epsom Salt: Epsom salt isn't as harmful to plants or vegetation as rock salt (or table salt). You may already have some on hand from the garden. It is an abrasive and melts ice slowly. To speed up your Epsom salts' melting power, combine sugar and Epsom salt in a 1:1 ratio.
Salt doesn't melt ice if the pavement is below 15 degrees, so use sand for traction when it's too cold, or choose a different de-icer.
Road salt is also called rock salt. It is a compound of sodium and chloride, the same chemical makeup of table salt. The difference between road or rock salt and table salt is that table salt is ground much finer, is often purified and has additives like Iodine and anti-clumping aids.