High-rise window washing is not for old men.

Salvador Villalobos is, at 59, the oldest in the city, he says.

“My shoulders are killing me now,” says Villalobos, who has been on the job for 30 years and wears a mustache flecked with gray.

On Monday, on what would have been a perfect day for slopping suds on windows, Villalobos and about 200 other striking window washers took to the streets downtown, protesting what they say are poor wages — especially, given how treacherous the job can be and the toll it takes on the body, they say.

Villalobos started out at $9 an hour. Three decades later, his wage has risen to $20.50 an hour, but in that time the cost of health insurance has skyrocketed, say the window washers whose strike kicked off Monday.

The window washers, members of SEIU Local 1, announced last month that they would go on strike if they didn’t get higher wages. Their contract with a number of cleaning companies expired June 30.

SEIU Local 1 is part of a group of unions that owns the Sun-Times.

One of the cleaning companies, Corporate Cleaning Services, says SEIU demands are unreasonable.

“Corporate Cleaning Services operates on a commission-based system where the minimum amount paid to a high-rise window washer for seasonal work is $20.50 an hour – nearly double the $11 an hour that SEIU claims,” according to statement from the company. “The median household income in Chicago is $53,000 and 70% of our workers make more than that. We have offered to increase their pay by 27% over the next five years. SEIU has demanded an unreasonable and unprecedented 37% raise. We are proud of our investment in our workers, whether through the 16% raise we’ve given them since 2015 or by employing the only full-time safety director at a Chicago window-washing company. We will continue our commitment to investing in our workers and to bargaining in good faith.”

Many window washers say they love the job — the one-of-a-kind views of the city, the sunrises, the serenity.

Ask Villalobos which buildings he’s cleaned, and he’ll tell you: “Almost all of them.”

That includes the Hancock, which takes three workers and two weeks to clean from start to finish.

In his 30 years, he’s seen a little bit of everything on the other side of the glass he cleans.

“Everything,” he says. “People in action sometimes.”

He’s also had some close calls — such as three years ago, when an attachment to his chair broke, leaving him dangling on the side of a building in his harness, for 45 minutes.

“I don’t complain about the job, I complain about the pay,” he says.