Winter is when a fleet most needs washing and when washing is hardest to do. Road salt and liquid de-icers stick to trucks and corrode bodies, wiring and brakes. The trade’s main defense is regular soap and water, weekly for trucks on treated roads. Below freezing the job changes. You need hot water, a plan for the ice you make, and equipment that’s drained every night.
What de-icers do to trucks
States clear roads with chlorides. That means rock salt, salt brine, magnesium chloride and calcium chloride. The American Trucking Associations’ maintenance council (TMC) warned in 2002 that magnesium chloride and calcium chloride products lead to more corrosion on vehicles, “causing significant damage in as quickly as a single winter season.”
The liquids are harder on equipment than rock salt for a plain reason. AAA says they stay liquid at lower temperatures and work into crevices that salt might not reach. A fleet executive at a tank carrier told Transport Topics what builds up on a truck. Sand, calcium chloride, magnesium chloride and road salt make “quite a paste, which is hard to remove and helps to keep the moisture in.”
The damage shows up in truck bodies, suspensions, wiring and brakes, and it can get into the cab and eat the floor. One parts supplier calls the bottom four feet of the truck “the hot zone” for corrosion.
What it costs
- AAA estimated in 2017 that rust from de-icers costs US drivers about $3 billion a year in repairs. That’s drivers’ own vehicles, not fleets.
- TMC surveyed 50 fleet maintenance managers in 2004. 87% had seen a part fail early from corrosion, and 63% had a road call because of it.
- A study done for the American Trucking Associations, reported in 2007, put the cost to the US transportation industry at $23 billion a year. We didn’t find a newer figure.
What works
Regular washing. Ohio’s DOT washes its own trucks with soap and water often, and its spokesman told Transport Topics, “We’ve tested a variety of anti-corrosion products, and honestly, soap and water is just as effective as anything.”
Every week, if the trucks run treated roads. One carrier that sends tractors and trailers through its wash bay weekly says it has added about three years to the life of its trailers.
The underside. A wash equipment builder told FleetOwner that underneath the vehicle “is where much of the harmful chemical residue ends up and where many important and costly components are located.” An undercarriage flush is the winter add-on worth selling.
Soap and some scrubbing where it’s caked. A trailer maker told Transport Topics that the newer road salts “adhere to surfaces to the point where a pressure wash isn’t enough.” Another trailer maker’s advice was “water and a little elbow grease.” He also warned against blasting strong cleaning solution into seams, where it stays and corrodes.
Anything beats nothing. A manager at one fleet called himself “a strong proponent of regular washing, even if it is just spraying it off.” Minnesota’s DOT also uses salt removers or neutralizers on its own equipment after storms.
Washing when it’s below freezing
The fleet sources don’t cover this part. It comes from pressure washing guides and from what water does when it freezes.
- The ice you make. Runoff freezes on the lot. Decide where the water will go before you start, keep it off walkways and drive lanes, and carry sand or ice melt for what’s left.
- Hot water. Soap works less well in the cold. A hot water machine makes up for some of it.
- Time of day. When the schedule allows, wash in the warmest hours.
- The trucks. Water can freeze in door seals and locks and around brakes on a truck that sits. Ask the fleet how they want the units left.
- Your equipment. Water left in a pump, hose or gun freezes, expands and cracks it. Drain and blow out the lines after the last stop, run pump antifreeze through the way the manufacturer says, and park the rig somewhere heated if you can.
- Your crew. Wet and cold is a bad mix. Carry spare dry gloves, work in pairs, and spray downwind.
- A cutoff. Pick a temperature, wind included, below which you don’t wash. Tell customers what it is before the season starts.
The wash water rules don’t take the winter off. Soapy water left on the pavement ends up in the storm drain when it melts. See where wash water can legally go.
Selling and scheduling winter
Offer a winter schedule. Weekly from the first salt to the last, with an undercarriage flush, then back to the usual gap in spring. One operator’s 2026 price list has the flush at $18 a unit. We cover schedules in how often fleet trucks should be washed.
Winter washes take longer. Keep your minutes per unit by season, so the winter number goes into the winter price. And when the weather cancels a visit, write down why and put it back on the schedule.
Common questions
How often should trucks be washed in winter?
Weekly, for trucks that run salted or treated roads. A wash equipment builder told FleetOwner that where salt is used, washing should be done as often as possible, and one carrier credits weekly washing with about three more years of trailer life.
Can you pressure wash trucks when it’s below freezing?
Pressure washing guides say to avoid it when you can. When you can’t, use hot water, decide where the runoff will go, put sand or ice melt on what’s left, and drain the pump, hoses and guns afterward, because water left inside freezes and cracks them.
What removes road salt from trucks?
Soap, water and some scrubbing. Ohio’s DOT says soap and water worked as well as any anti-corrosion product it tested. A trailer maker says some newer de-icers stick so hard that pressure alone won’t take them off.
How The Wash Book does it
In The Wash Book a yard’s schedule can change with the season, and a skipped visit keeps its reason. Book a demo and we’ll walk you through it, or start free with unit tracking.
Sources
- Transport Topics, Fleets Implement Techniques to Fight Corrosion From Salts (2021)
- Transport Topics, Corrosion Takes Increasing Toll on Fleets, Trailers (2007)
- Heavy Duty Trucking, Caustic De-Icing Chemicals Plague Trucking (2004)
- FleetOwner, Washing trucks regularly a wise choice (2002)
- AAA, Road De-icers and Rust Damage fact sheet (2017, PDF)
- Ultimate Washer, Winter Safety Tips
- For Construction Pros, How to Winterize Pressure Washers
- Britewash, Fleet Washing Cost: 2026 Prices