Without a doubt, insights on deicing and anti-icing operations are some of the most sought-after information among snow and ice management professionals. Everyone is seeking some sort of professional advantage that will allow them to improve their on-site efficiency, cut costs, exceed client expectations, add to their profit margins, and – perhaps most importantly – reduce their and their client’s vulnerability to slip-and-fall claims.
For example, I frequently spend time pouring over web analytics data for Snow Magazine’s website. It’s sort of like reading the editorial tea leaves to gain insights on what is top of mind among snow and ice management professionals. It’s a fair estimation that, at any time of the year, of the Top 10 requested topics/articles, easily 60%-70% have to do with some aspect of salting, deicing or anti-icing strategy.
So, I went back through nearly two decades of editorial material and culled some of the best of the best material. In many cases, I updated existing information and augmented it with new content to create this month’s cover story. By no means is this the end-all, be-all primer on salting, deicing and anti-icing because, as with a lot of things, this strategy is fluid (pardon the pun) and is constantly evolving, improving and getting better. But hopefully on the following pages you’ll find some useful tips or insights that make you reflect on your own strategy and how you can achieve greater results in the field. And as always, I’d love to hear your feedback on what you’re doing within your own snow and ice management operation to improve performance, increase your efficiency, and strengthen your margins. So, don’t hesitate to reach out: email@example.com. And as always, have a safe and profitable winter. – Mike Zawacki, editor
For snow and ice management professionals, timing is crucial in applying salt. The melting action of rock salt or other ice-control chemicals applied early in a storm works from the pavement surface up so snow and ice do not form hardpack.
Most snow and ice pros subscribe to two strategies. Anti-icing activities take place before any accumulation to prevent snow or ice bonding to the pavement; and deicing where rock salt is spread as soon after a storm begins to penetrate the bonded, frozen precipitation, produce brine, and keep snow mealy to allow for more efficient plowing.
As temperatures drop, either the salt amount or the application frequency must increase to address and thwart ice buildup. However, there are storm conditions where a deicing agent like salt/brine is the only answer to keep pavement clear. For example, freezing rain cannot be plowed and deicing is the only solution for keeping surfaces clear of frozen buildup.
Since winter-event forecasts are not always precise, a professional snow and ice manager’s strategy relies on close monitoring. And when done successfully, anti-icing is the best means to prevent ice accumulation.
Anti-icing measures take place in the hours prior to the first precipitation. Anti-icing products are applied in liquid form – brine being the most common – to prevent snow and ice from bonding to pavement surfaces. Popular chemical combinations in anti-icing programs include sodium chloride, calcium chloride, magnesium chloride, potassium acetate, and calcium magnesium acetate. Each anti-icing product has its own unique pros and cons. For example, calcium or magnesium chloride in a brine solution is effective at very low temperatures, but it can be as much as six times more expensive than rock salt. The most common material, though, is sodium chloride (salt) in brine form – a mixture of rock salt and water. Salt brine is effective to -6° F.
However, as the storm progresses scenarios may call for a snow professional to switch to conventional deicing. Snow and ice control is a complex issue and snow and ice managers require the most timely and accurate data available so they can apply their professional judgment to implement a customized strategy for each snow-and-ice event. There are no simple answers with ice control because winter events include so many variables – pavement temperature, ambient temperature, pavement type, solar radiation, traffic (vehicle and pedestrian) volume, wind direction and velocity, precipitation type, topography, lake or ocean effect, shaded areas (from trees or buildings) and wind chill factor, to name a few.
Therefore, professionals are encouraged to educate themselves on the products they use, including accessing as much educational material and training from product manufacturers and/or vendors as possible. In addition to product education, enough can’t be said about seeking and sharing experienced-based knowledge, whether it’s based on a snow professional’s own experience or that of a trusted industry colleague.
Many snow fighters have found that prewetting salt with a 23 percent solution of liquid sodium chloride, a 32 percent solution of liquid calcium chloride or a 32 percent solution of magnesium chloride speeds the reaction time of salt and also provides melting at lower temperatures.
This provides a better level of service at all temperatures. Prewet salt goes into solution faster, speeding its friction-recovering mission. And prewet salt also sticks better to pavement so more stays in place rather than bouncing into irrelevant areas. In some cases, prewetting’s increased efficiency will decrease the quantity of salt required.
Prewetting, done at rates of 8 to 10 gallons per ton of salt, can be applied via a number of methods. For example, on-board where the liquid is in a tank and dispensed as the salt leaves the spreader, applied to each loader-bucket of salt prior to placing in the spreader, applied to the entire load in the salt spreader, and applied to a stockpile.
A LIQUID STRATEGY
The application of liquid anti-icing materials to road and walkway surfaces prior to an event has the potential to increase a snow professional’s efficiency while boosting profit margins. Many industry professionals swear by their effectiveness, whether they’re applying brine or another liquid product. Consider the following points when formulating your liquid strategy.
Less Material. Liquid ice-fighting materials penetrate pavement surface pores and are not disturbed by vehicle or foot traffic. Therefore, less material is required to melt ice, with some snow pros estimating a 64% reduction in both material and labor costs. Applying ice-melting chemicals before a storm is more effective at mitigating ice buildup than applying an ice-melting material after ice has formed.
And due to their penetrative qualities, liquid ice-melting chemicals have a residual life within the pavement. However, water (rain and/or snow melt) will wash liquid agents from the pavement. So, if rain is forecast before the the event kicks in, you’ll lose a good portion of the applied material.
Cost, Not Price. Ice-fighting chemicals tends to cost more than bulk rock salt. Therefore, contractors must consider the big picture, such as total vehicle drive time and related expenses, storage requirements and level of service, that liquid solutions offer.
Less Plowing Time. Applied prior to an event, the chemical agents inhibit the bond between snow and the pavement. As a result, snow clearing is more efficient and effective, which some estimates reduces a contractor’s on-site plow time by a factor of five.
No Magic Bullet. Despite their benefits, liquid are one tool in a snow pro’s toolbox. A strategy that includes both anti-icing and traditional de-icing will be required for effective and efficient total storm management.
Knowledge and Experience. All the benefits liquids provide snow and ice management professionals are rendered void if a product is used improperly or counter to manufacturer’s recommendations. Each liquid agent has a different temperature window and concentration in which they are most effective at managing ice formation and buildup. Used outside of the product’s performance guidelines and tolerances, snow professionals will not achieve the intended results. This leaves contractors vulnerable to unhappy clients, or worse, costly slip-and-all liability.
Mind The Melt. As liquid products convert ice and snow into water, their concentration dilutes, which decreases their effectiveness. Knowledge of the performance curve of the materials being used grants contractors the ability to adapt the strategy and respond appropriately.
Job site and environmental conditions will largely determine who the contractor applies and distributes salt and other deicing materials on a client’s property. Therefore, snow and ice professionals should pay particular attention to the variables that impact the way their salt is being spread on clients’ sites. For example
- Encourage plow drivers to abide by spinner speeds. A spinner that revolves too fast throws salt over a wider area, possibly wasting material. Contractors can correct “overthrow” by readjusting the drop location on the spinner by using the directional baffles or reducing spinner speed.
- Strong winds blowing across a client’s property will cause salt to drift and distribute unevenly as it comes out of the spreader. Therefore, note wind conditions, especially on properties with no wind breaks. Prewetting counteracts windy site conditions.
- Monitor weather and temperature conditions. As pavement temperatures lower – for example on sunless days or at night – operators will need to adjust application rates for more effective results. Without the sun, the effect of solar radiation and warmth is lost from the contractor’s ice mitigation strategy.
- Pavement temperature is rarely the same as air temperature. Be sure to regularly measure, monitor and record both accordingly on each client’s site.