“You don’t know how dirty it is until you clean it.”

That’s dairy barn roof cleaner Les Schmidt’s motto, which he effectively demonstrates in a drone video on his website. Schmidt appears to be a dot on the peak of a vast roof, lowering a steaming washer down the steel ribs, leaving an obvious white path next to unwashed grey metal.

Others may not have paid attention, but about a decade ago the Wisconsin entrepreneur noticed that roofs of 10-year-old free-stall dairy barns were starting to look shabby.

“It’s a maintenance issue, and there are people who want to keep their place looking nice,” Schmidt says. “Cleaning the roof changes the appearance of the whole facility.”

He built a washer specifically designed to clean metal roofs. The 4-ft. wide deck of the washer has 4 high-pressure nozzles underneath that spray 150 to 160-degree water. Six wheels, four in front and two in back, adjust to follow the ribs. Four jacks are raised or lowered according to the rib height. A black poly ring around the outside prevents the washer from scratching the metal.

Water is continually heated from a 500- gal. nurse tank through a hot water boiler/burner and 12 gpm/3,000 psi pressure pump inside an enclosed service trailer. Schmidt uses the hose to let the washer down and pull it up as he works across the roof.

“I can cover 25,000 sq. ft. in a day,” Schmidt says. He typically sets up to wash 200 ft. of roof on each side.

When the roof pitch is steep, he hires a helper. One lets down and pulls up the washer, while the other lifts the back end and moves the washer to the next section of roof to clean.

“It’s way more difficult than it looks (on the video), especially dealing with safety,” Schmidt says, noting he uses harnesses on some buildings.

Demand for Schmidt Exterior Cleaning keeps him busy throughout the Midwest. Clients typically have large operations – 1,200 to 5,000 cows – and Schmidt may spend a week or so in an area cleaning barns for different owners.

He charges expenses and by the square foot, according to how dirty and steep the roof is. Schmidt adds that he also does fan and curtain cleaning.

“My goal with my company is for people to grasp how dirty their exterior has become and recognize they can have the beautiful, fresh look all the time,” Schmidt says.