Critical conditions

When implementing a deicing and anti-icing program, there are many factors to consider. Snow and ice management professionals must assess what product is best for various pavement and weather conditions, as well as how much product should be used and the application method appropriate for the product.

When you are planning product application and applying product, there are a few important factors to keep in mind. Here are a few tips on the best practices, procedures and considerations when it comes to deicing and anti-icing.

Planning product application.

Consider Current Conditions. It is essential that the pavement is clear of snow or loose ice before applying chemicals to reduce resulting product dilution. The road surface can refreeze if precipitation or moisture on the pavement dilutes the chemical, or if pavement temperatures drop below the effective temperature of the anti-icing chemicals.

Identify Critical Areas. Schedule anti-icing applications on bridge decks and other critical areas beforehand if temperature and conditions could produce frost or black ice. Consider spot applications on hills, curves, intersections and turn lanes if predicted conditions warrant.

Consider The Product. Make sure to utilize the appropriate application rate based on the chemical you are using and the current and projected pavement temperature. Liquid anti-icing chemicals are not recommended in use with freezing rain; instead use a granular product.

Weather Factors. Do not apply chemicals before predicted rain.

It’s important to know that pavement temperature, rather than ambient temperature, drives the application rate. However, it is also important to pay attention to air temperatures because they can indicate pavement temperature trends. Utilize accurate pavement temperature and other road weather information to decide when to begin applying chemicals.

Do not apply anti-icing chemicals under blowing snow conditions and in areas prone to drifting. Be aware of areas that are prone to wind issues.

Application tips.

First Application/Dry Spells. Apply liquids at approximately half the normal rate (not half the concentration) on dry roads because liquids tend to mix with petroleum products from vehicles and can potentially cause slippery conditions.

Method Of Application. When applying product with only streamer or pencil nozzles, maintain some bare pavement between sprayed lines to reduce slipperiness. Fan spray is not recommended.

Do Not Shoot And Run. The application of anti-icing chemicals requires constant monitoring of precipitation rate, temperature, traffic and dilution of the product. If the storm is severe, consider using only mechanical snow removal until the severity lessens, and then resume liquid treatments.

Less Is More. Only apply the minimum amount of chemical needed to meet the defined level of service. Do not apply too much chemical or the pavement may become slippery. Remember, it is always important to follow the product’s application recommendations.

Anti-icing is the snow and ice control practice of preventing the formation or development of bonded snow and ice by timely applications of a chemical freezing-point depressant. Anti-icing chemicals, if used as part of a proactive operations plan, can substantially reduce materials usage, wear and tear on maintenance equipment, and personnel time.

The author is a technical expert and west region account manager for EnviroTech Services.