Liquid Deicing Best Practices: Application Rates, Timing & Production Strategies
Quick Answer
What are the recommended liquid deicing application rates?
Liquid deicing application rates depend on the type of treatment and current conditions. Use 40–50 gallons per acre (GPA) for standard pre-treatment, 80–100 GPA for post-treatment, and 60–80 GPA for interstorm applications. Heavier snowpack or icing may require rates of 100–120+ GPA.
| Application | Standard Rate | Timing | Primary Goal |
|---|---|---|---|
| Pre-treatment | 40–50 GPA | 24–48 hours before a storm | Prevent snow and ice from bonding to the surface |
| Post-treatment | 80–100 GPA | As soon as plowing is complete | Address residual snow and ice |
| Interstorm | 60–80 GPA | During extended or changing storm conditions | Refresh surface protection and prevent ice or snowpack |
| Heavy accumulation / icing | Up to 100–120+ GPA | When conditions require additional treatment | Address heavier residual snowpack or ice |
Definition
GPA (Gallons Per Acre): The amount of liquid deicing material applied to one acre of pavement. Application rates are adjusted based on weather, pavement conditions, snow moisture and the amount of residual snow or ice.
Liquid deicing can help snow and ice management professionals improve efficiency, reduce material use and prevent snow and ice from bonding to pavement. The key is applying the right amount of liquid at the right time and adjusting the application to match weather, surface and site conditions.
This guide covers liquid deicing application rates, treatment timing, application adjustments, brine quality and production strategies to help contractors get more from their liquid deicing operations.
What Is Pre-Treatment Liquid Deicing?
Pre-treatment, also called anti-icing, is applied before a storm to prevent snow and ice from bonding to the pavement and to limit mild accumulation. Salt brine is particularly well suited to this type of proactive treatment. Learn more about how salt brine works for ice prevention ↗
The standard application rate for pre-treatment is 40–50 gallons per acre (GPA). The objective is broad, even coverage that reaches the pores of the surface.
Recommended Pre-Treatment
- Application rate: 40–50 GPA
- Timing: Typically 24–48 hours before a storm
- Goal: Prevent snow and ice from bonding to the pavement
- Coverage: Broad, even coverage across the treated surface
- Typical boom configuration: Small side nozzles with a center boom fan tip
Pre-treatment helps make subsequent mechanical snow removal easier. By preventing a strong bond between snow, ice and pavement, plows can achieve a cleaner scrape, which can also reduce the amount of liquid needed for post-treatment.
The effective treatment window can be longer when a quality additive is used, but actual performance depends on the product and weather and surface conditions.
What Is Post-Treatment Liquid Deicing?
Post-treatment is applied after plowing to address residual snow and ice that remains on the surface.
The standard post-treatment application rate is 80–100 GPA.
Recommended Post-Treatment
- Standard application rate: 80–100 GPA
- Timing: As soon as plowing is complete
- Goal: Address residual snow and ice
- Typical boom configuration: Medium or large side nozzles with a center boom pencil stream
- Application approach: Use sufficient pressure to reach the surface
The amount required can vary considerably based on how well the surface was mechanically cleared. A very clean scrape may require less liquid, while a site with significant residual snowpack or ice may require substantially more.
What Is Interstorm Liquid Deicing?
Interstorm applications are used during extended events or when changing weather conditions create a new risk of icing.
For example, during an event that changes from rain to freezing rain or snow, a secondary liquid application can help prevent moisture from bonding to the pavement. Interstorm applications can also be useful during long-duration snow events when the original pre-treatment is no longer providing sufficient protection.
Recommended Interstorm Treatment
- Standard application rate: 60–80 GPA
- Timing: Around the transition from rain to freezing rain or during the middle of a long-duration snow event
- Goal: Refresh the treatment and prevent ice or snowpack from forming
- Typical boom configuration: Medium side nozzles with a center boom pencil stream
Preventing ice or snowpack from forming is generally easier than removing it after it has frozen to the pavement.
If conditions do not allow an interstorm application, increasing the final application rate to 100–120 GPA may help address site conditions.
How Should Liquid Deicing Application Rates Be Adjusted?
Definition
Application Rate: The volume of liquid deicer applied to a specific area, typically expressed in gallons per acre (GPA). The appropriate rate varies with storm and surface conditions.
There is no single application rate that is appropriate for every storm or every property.
Application rates should be adjusted according to weather, surface conditions and the quality of snow removal with a snowplow.
Snow Moisture
The higher the moisture content of the snow, the higher the application rate may need to be.
When moisture content is higher, consider adding approximately 20–40 GPA above the standard application rate.
Quality of Snow Removal with a Snowplow
Snow removal has a direct effect on the amount of liquid needed afterward.
A very clean scrape can reduce the post-treatment application rate by approximately 10–20 GPA.
Conversely, poor mechanical removal may require an additional 20–30 GPA or more.
For example:
- A slight glaze remaining after good plowing may be addressed with approximately 40–60 GPA.
- A heavy snowpack or layer of ice may require 120 GPA or more.
The better the mechanical removal, the more consistently liquid deicing can perform.
High Winds
High winds are another factor to consider.
Avoid liquid application during high winds and wait until winds subside when possible. Wind can cause blowing snow to adhere to a treated parking lot rather than blowing across the surface.
Why a Single 80 GPA Rate Isn't Always Ideal
A contractor might use 80 GPA as a standard post-treatment rate for every site and every storm. However, this can result in both over- and under-application.
An 80 GPA rate may be more material than necessary on a well-seasoned lot with a very clean scrape. The same rate may not provide enough treatment for heavy snowpack or significant icing.
For that reason, application rates should be adjusted per storm and per site rather than treating 80 GPA as a universal rate. Automatic rate control can make those adjustments easier and more consistent.
For a broader look at the operational benefits and considerations of liquid deicing, see Liquid De-Icing: Pros and Cons↗
How Do Refill Stations Improve Liquid Deicing Production?
The location of liquid refill stations can have a significant impact on production.
Remote refill stations can be positioned along centrally located routes so trucks spend more time spraying and less time traveling to refill. These tanks can be filled before a storm or replenished afterward in preparation for the next event.
This becomes particularly important when calculating effective production rate. A sprayer's theoretical application capacity is different from the amount of area a crew can actually service during a storm.
How Is Liquid Deicing Production Rate Calculated?
Definition
Effective Production Rate: The amount of pavement an operation can treat in a given period after accounting for application time, travel time, refill time and other operational delays. It is typically expressed in acres per hour.
An effective production rate is different from an application rate. An application rate tells you how much liquid is applied per acre; an effective production rate tells you how much area the operation can actually service over time.
Production rate depends on more than how quickly liquid can be sprayed. An effective production calculation should account for:
- Tank capacity
- Application rate
- Application time
- Travel time
- Refill time
- Route and site size
Consider this example:
- Tank capacity: 1,000 gallons
- Application rate: 80 GPA
- Average site size: 2.5 acres
- Average travel time: 10 minutes between sites
- Refill time: 10 minutes
- Application time: Approximately 4 minutes per acre
- Number of spray trucks: Two
Improve Production by Reducing Travel Time
A localized liquid refill strategy can reduce travel time and increase the amount of area a crew can treat during a storm.
|
TRUCK #1
1,000-Gallon Spray Unit
80 GPA application rate
10-minute average drive to Site #1
Average site size: 2.5 acres
|
TRUCK #2
1,000-Gallon Spray Unit
80 GPA application rate
10-minute average drive to Site #1
Average site size: 2.5 acres
|
| Application Rate 80 GPA covers approximately 12.5 acres, or 5 average sites. |
Average Application Time Approximately 4 minutes per acre using a 1,000-gallon unit and 3-lane boom system. |
|
50 min
Travel Time
|
10 min
Fill Time
|
50 min
Spray Time
|
Under the same operating model, reducing average travel time between sites can increase effective production from approximately 6.8 acres/hour to 8.9 acres/hour.
Step 1: Calculate Acres Covered Per Tank
The first calculation determines how much area a 1,000-gallon tank can cover at an 80 GPA application rate:
1,000 gallons ÷ 80 gallons per acre = 12.5 acres per tank
At an average site size of 2.5 acres, one 1,000-gallon tank can theoretically cover approximately five average sites before needing a refill.
Step 2: Calculate Application Time
At approximately 4 minutes of application time per acre:
12.5 acres × 4 minutes per acre = 50 minutes of spray time
The route therefore requires approximately 50 minutes of active application time to treat 12.5 acres.
Step 3: Add Travel and Refill Time
The example route includes approximately:
- 50 minutes of travel time
- 10 minutes of refill time
- 50 minutes of spray time
That creates a total operating cycle of:
50 minutes travel + 10 minutes refill + 50 minutes spray = 110 minutes
Step 4: Calculate Effective Production Rate
The effective production rate accounts for the entire 110-minute operating cycle—not just the time spent spraying.
The calculation is:
12.5 acres ÷ 110 minutes × 60 minutes per hour = approximately 6.8 acres per hour
Under these assumptions, the effective production rate is approximately 6.8 acres per hour.
This distinction is important:
80 GPA is an application rate.
6.8 acres per hour is an effective production rate.
The first tells an operator how much liquid to apply to each acre. The second describes how much area the operation can actually service when application, travel and refill time are included.
How Can Reducing Travel Time Increase Production?
The same equipment and application rate can produce more acres per hour when operators spend less time traveling between customer sites. In the example above, reducing average travel time from 10 minutes to 5 minutes reduces nonproductive travel time while leaving the application rate unchanged.
Under the example's operating assumptions, that reduction in travel time increases effective production from approximately 6.8 acres per hour to 8.9 acres per hour. That represents an increase of approximately 31% in effective production without increasing the application rate.
The operational lesson is straightforward:
Reducing travel time can increase production without increasing the amount of liquid applied per acre.
Strategically located liquid refill stations can help accomplish this by allowing trucks to spend more time treating customer sites and less time traveling to a central refill location.
Production-Rate Example at a Glance
1,000 gallons ÷ 80 GPA = 12.5 acres per tank
12.5 acres ÷ 110 minutes × 60 = approximately 6.8 acres/hour
Reducing average travel time from 10 minutes to 5 minutes can increase effective production to approximately 8.9 acres/hour.
These figures are an operating example rather than a guaranteed production rate. Actual production will vary based on site size, route layout, traffic, weather, application rate, equipment, operator performance and refill logistics.
How Should Additives Be Used With Liquid Deicing?
Additives can be blended with salt brine to provide additional performance characteristics, including improved adhesion, corrosion protection and performance in colder conditions.
Consider using a quality ready-made additive when working temperatures fall below 15°F. Additives may also be useful in high-moisture conditions or when additional performance benefits are desired.
Depending on the additive, potential benefits include:
- Tackifiers that help the product remain on the surface through traffic, wind and rain.
- Corrosion inhibitors that can reduce corrosivity compared with untreated rock salt.
- Polymers that can improve traction and change the characteristics of ice particles.
- Organic content that can lower the freezing point and provide additional refreeze protection.
Additive selection and blend rates should be based on the product, temperature and site conditions rather than assuming one blend is appropriate for every application.
What Salt Purity and Brine Salinity Should Be Used?
For brine production, salt should be at least 95% pure. Higher-quality salt can reduce issues with slow mixing, fallout, refreeze and plugged spray-equipment filters.
Proper brine salinity is also important.
A 23.3% salt brine concentration is the eutectic point of salt brine, equivalent to approximately 2.28 pounds of salt per gallon of water.
Definition
Eutectic Point: The lowest temperature at which a salt-and-water solution can remain liquid at a specific concentration. For sodium chloride brine, the eutectic concentration is approximately 23.3%.
Increasing salinity beyond that point does not necessarily improve performance and can actually increase the freezing temperature of the solution.
Contractors should monitor brine salinity whether brine is produced in-house or purchased from another supplier.
Using the appropriate amount of deicing material is also important from an environmental perspective. Learn more about how liquid deicing can reduce the environmental impact of road salt ↗
Frequently Asked Questions
What is the difference between anti-icing and deicing?
Anti-icing is the application of liquid deicer before or during a winter weather event to prevent snow and ice from bonding to pavement. Deicing is the application of material after snow or ice has accumulated to help break the bond between the frozen material and the pavement.
How many gallons of liquid deicer are needed per acre?
The appropriate application rate depends on conditions. A standard pre-treatment rate is generally 40–50 gallons per acre (GPA), while standard post-treatment is generally 80–100 GPA. Interstorm applications typically use 60–80 GPA. Rates may need to be increased for higher-moisture snow, heavy snowpack or significant icing.
Can you use the same liquid deicing rate for every storm?
No. Liquid deicing application rates should be adjusted based on weather, pavement conditions, snow moisture and the quality of mechanical snow removal. Using one fixed rate for every storm can result in over-application under some conditions and under-application under others.
Does plowing affect how much liquid deicer is needed?
Yes. Effective mechanical snow removal can reduce the amount of liquid deicer required for post-treatment. A clean scrape may require less liquid, while significant residual snow or ice may require a higher application rate.
What is the best time to apply liquid deicer?
For anti-icing, liquid deicer is generally applied 24–48 hours before a storm, depending on the forecast and site conditions. Post-treatment should be applied as soon as practical after plowing, while interstorm applications can be used when conditions change or a long-duration storm requires additional treatment.
How can liquid refill stations improve snow removal production?
Strategically located liquid refill stations can reduce travel and refill time, allowing spray trucks to spend more time treating customer sites. In the production example in this article, reducing average travel time from 10 minutes to 5 minutes increases effective production from approximately 6.8 to 8.9 acres per hour.
What is the difference between application rate and production rate?
Application rate is the amount of liquid deicer applied to an acre, typically measured in gallons per acre (GPA). Production rate is the amount of area an operation can treat over time, typically measured in acres per hour. Production rate accounts for factors such as spraying, travel and refill time.
How much salt should be used to make brine?
Salt should be at least 95% pure for brine production. Proper brine concentration is also important. A sodium chloride brine concentration of approximately 23.3% is the eutectic point, so adding salt beyond the saturation point does not necessarily improve performance.
When should additives be used with salt brine?
Additives may be useful when additional performance characteristics are needed, such as improved adhesion, corrosion protection or cold-temperature performance. They can be particularly useful when working temperatures fall below 15°F, depending on the product and conditions.
Does more liquid deicer always mean better performance?
No. More liquid is not necessarily better. Applying too much material can waste product, while too little may not provide adequate treatment. The goal is to select an application rate appropriate for the weather, pavement, snow or ice conditions and quality of mechanical removal.