As a California native, I never truly experienced a below-freezing day until I moved to a colder region of the United States. What I once imagined to be a cozy winter wonderland quickly turned into a slippery and frigid catastrophe. However, working for a company that specializes in snow & ice removal has allowed me to learn the nitty-gritty facts of snow and ice.
The question we get most often when discussing prevention services with our clients is, “what is exactly is De-icing?” So here I am to tell you all the facts you need to know before those ice-cold temperatures start making the ground a lot harder to walk on.
De-icing vs. anti-icing?
So, what are anti-icing and deicing? Sodium chloride and calcium chloride are the short answer since they are the most commonly used products to control ice across the United States. When these chemicals are present on surfaces, they make it harder for ice to be present and bonded to surfaces.
When mitigating the risk of icy surfaces, there are two options: deicing and anti-icing. De-icing melts ice or snow while anti-icing reduces the chances of ice formation. The circumstances of the cold weather usually decide whether you should be anti-icing or deicing.
Anti-icing, as the name implies, is a preventative measure used to prevent ice from forming on surfaces. Sodium chloride/salt is used just before temperature drops. This salt works by absorbing heat and lowering the freezing point for water molecules, which is fancy science talk is called endothermic. This strategy tends to be more cost-effective since sodium chloride tends to be more abundant, and you need less of this chemical to be effective.
Deicing is a reactionary measure used to melt snow and ice. The most commonly used deicing agent is calcium chloride, which works by releasing heat when it comes into contact with water molecules. This process is known as exothermic since it provides warmth to expedite the melting process of snow and ice.
It is essential to know all the facts before spreading these chemicals on properties. Consider the possible environmental effects, storing conditions, and the equipment required to handle these chemicals. Other chemicals that are less commonly used in treating snow and ice are magnesium chloride and calcium magnesium acetate.
The first and perhaps most important to consider before making a decision on de-icing is the surface of the property you are planning on de-icing. Questions to consider are: How much foot/vehicle traffic is this surface getting during snow and ice formation? What is the surface made of? How much of this surface is exposed to low temperatures?
Whether you are planning on de-icing your neighborhood sidewalk or the parking lot of a megastore, it is crucial to consider the costs and labor required to de-ice a property. De-icing agents become challenging to obtain in large quantities during cold weather due to supply and demand issues, which is why it is crucial to consider the traffic levels in any given area.
Not all surfaces are created equal. Concrete and asphalt being the most common type of surfaces, are the best example of this. Due to its lighter color and high density, concrete tends to heat up and cool down much slower than other surfaces. In contrast, asphalt heats up much faster and cools down much quicker as well once the sun stops hitting its surface. De-icing should be applied according to the surface temperature of these structures.
Exposure to the Cold
Every surface is different, and since they all have different exposure levels to the cold. Shady areas will tend to freeze faster and stay frozen due to the absence of the sun’s heat. Another thing to consider is the amount of cold exposure to the overall surface structure, like bridges. The reason bridges tend to freeze is due to the top and bottom surfaces being exposed to the cold.
So now that you know the facts about snow and ice treatments, how does it work?
1. Anti-icing salts are preemptively spread on dry surfaces. Deicer is spread on settled ice or compacted snow.
2. Salt draws moisture and forms brine . Brine is heavier than water and burrows downward to the surface.
3. Brine weakens the ice-surface bond. The moistened chemical provides the energy to weaken the ice-surface bond and begins to tum the ice into liquid or slush.
4. Traffic breaks through to the surface, and along with other factors, reduces the remaining snow/ice to slush.
The effectiveness of anti-icing and deicing depends on the temperature, moisture levels in the environment, existing site conditions, timing of application, and weather conditions. All these factors working together will determine the difference between a safe or a slippery surface. But before going out and buying a truckload of sodium chloride, consult snow and ice professional like Transblue!