If you look at the nation’s stuttering economy one of the few bright spots can be found in the service industry—more than 70% of jobs lost in that sector during the recession have returned. The catch? Many are low-wage. In fact today at least 20% of all Americans work in low-wage service jobs: cashiers, restaurant bussers, in-home care workers and of course, janitors.

Janitors in Houston are among the lowest paid in the nation, though they clean the offices of some of the richest companies in the world in a city that’s booming. Hundreds of janitors who belong to the Service Employees International Union have been on strike since their contract expired in May, asking for a pay raise—from $8.35 to $10 an hour over the next 3 years. They also want the city to answer the question: just how low can a low-wage be and still be fair?

Marketplace’s Krissy Clark visited some of the high-rises that form Houston’s skyline, to eavesdrop on conversations between people who work at opposite ends of the city’s booming economic horizon.

***

I found that skyscrapers in Houston, like most skyscrapers, are places where janitors and the people whose offices they clean usually pass like ships in the night. Or, more precisely, the elevator. They might exchange pleasantries. Likely in Spanglish.

Hello, how are you? Fine thanks, y you?

That’s about it.

Since janitors and office workers keep different hours and often speak different languages, the gulf between their lives isn’t surprising. But it’s weird, too. Everyday they walk (or vacuum) the same carpet. They breathe (or deodorize) the same air. They even gaze at (or dust) the same framed family photos.

Lorenza Delgado, a janitor at Wells Fargo Plaza in Houston, says when she dusts those pictures – of smiling families on vacation or at a wedding—she feels connected to the people who work at those desks.

“They’re just like me,” she says in Spanish, through a translator. “They love their families and they’re working to provide a better future for them. And that’s why they keep them close.”

Delgado doesn’t have a desk at work to display photos of her own daughter, Leonarda, but thereare pictures of the six year old covering every surface of their living room—a tiny, stuffy place in one of the poorest neighborhoods in Houston. Leonarda standing next to a model rocket ship.  Leonarda’s diploma for completing preschool. Leonarda at school picture day in kindergarten.

A class photo including Delgado's daughter, Leonarda.

“Muchas Leonardas!” Delgado laughs. She runs through these images every night on her commute to work. Two and a half hours round trip by bus. But, she says, her family, her daughter, her day to day life—that stuff would rarely come up in the quick interactions she has with office-workers while she’s cleaning. Until a few years ago, when she met an administrative assistant on the 53rd floor named Erica Vasquez.

“The first time I met Lorenza, I was working a late night, and she came around to take out the trash. So I just started talking to her,” Vasquez recalls.

Vasquez is fluent in Spanish, which made it easier to talk with Delgado, who speaks limited English. Still, their conversations were brief. With so many offices to clean, Delgado literally runs through the halls to get it all done in her six-hour shift—the longest allowed by most janitorial companies in Houston, though the SEIU says janitors in other big cities get eight hours to do the same amount of work.

Despite the rush of their passing exchanges, little things came out that have given Vasquez a better picture of Delgado’s life. Vasquez was shocked to learn, for example, that Delgado was collecting the recyclables everyone thought the building was sorting.

“She would take the cans and get money for the cans to at least pay a bill or something,” she says. “The amount she makes barely pays enough to pay the rent.”

Not to mention food, or school supplies, or Delgado’s diabetes meds. The $12,000 that Delgado makes a year is well below the poverty line for a family of two. “It’s not fair that they work so hard and get paid so little,” Vasquez says of janitors like Delgado. “I don’t know how she does it. You want to do something to help.”

Vasquez tried to get Delgado a higher paying job cleaning rooms at a hospital, but there wasn’t a good bus route to get her there. As for Vasquez’s bigger question of about fair pay? That’s exactly what striking janitors like Delgado are trying to get office workers in Houston to think about. They’re holding marches in front of buildings that punctuate the city’s booming corporate skyline, owned by companies like Exxon, Shell, and JP Morgan Chase.

“They’re taking all the money home with them,” says Alice MacAfee, who’s been a janitor for thirty years. “And we’re not getting a cut of it.”

Delgado works in a building like the one on the left. And houses like the one on the right are common where she lives.

Drew Woellner is a lawyer who works in one of those opulent downtown skyscrapers, and hears the janitor protests outside his window. He’s gotten to know some of the janitors who work in his office. “They’re very hard working people, they’re always very nice,” he says. “But I don’t know that cleaning the offices of people making more money necessarily correlates into what they should be making.”

But for most of the 20th century, that is how it has worked, according to Arin Dube, an economist at the University of Massachusetts.

“Used to be the case that regardless if the person was a CEO or the person who cleaned the CEO’s office, when the company was doing better, everyone tended to do a little better,” Dube says. “That has changed.”

One reason that’s changed, Dube says, is because today, janitors generally don’t work for the owners of the buildings they clean. Instead, they work for—and collectively bargain with-- subcontractors: often national or multi-national cleaning companies vying to be the lowest bidders for their customers, the building owners.

“You end up becoming hired by a middle man,” explains Dube. “And that makes it easier for a building owner to not have to pay higher wages when they’re doing pretty well.”

 Janitors protest for higher wages in Houston.

Which brings us to another recent conversation between a janitor and—not exactly a person who works in the building she cleans, but close—the CEO of the company the building is named after.

JP Morgan Chase is the third biggest commercial property owner in Houston. And last month, the man who runs it happened to be testifying before Congress. In a union publicity stunt, a janitor named Adriana Vasquez walked up toJP Morgan Chase CEO Jamie Dimon after his testimony. She cleans JP Morgan Chase Tower in Houston and, she says, she had a question for him that she’d been rehearsing all morning.

“Mr. Dimon” she asked. “You make the billions of dollars every year. Why do you deny the people cleaning your buildings a living wage?”

The exchange is captured here in this C-Span video. (Vasquez is the one wearing red in the video.)

Dimon told Vasquez to call his office. She’s still waiting to hear back. When I called Chase and the other major building owners in Houston to ask about janitors wages, I got answers like this:

Technically, those company spokesmen are correct, says Arin Dube, the University of Massachusetts economist. It’s not like Chase, Exxon, or any of the other companies that dominate the Houston skyline are directly dictating the terms of janitors pay. But, Dube says, they hire the contractors who do. And there’s another simple way the Chases and Exxons of the world are connected to the janitors.

“Every employee including their CEO presumably needs to use the bathroom. And when they go in to the bathroom, it has to be clean,” says Dube. “This is a very basic necessity that is filled: They can’t work in an office overrun with trash.”

And thanks to janitors like Hernan Trujillo, they don’t have to. He started cleaning offices soon after graduating from high school, to help pay for his mom’s medical bills when she got sick. He says he can’t help but notice the photos on the desks he cleans.

“When I work in the floors, I always look in the pictures and I’m always imagining ‘Wow, there are so many happy faces!’” he says. The vacation pictures, the baby pictures, he loves looking at them. But there’s one kind of photo that gets to him. "When the kid is graduating from college," he says. Then he apologizes, because he is crying. “That was one of my parents’ dreams," he says.

Trujillo composes himself and explains that's why janitors are striking in Houston. If they got paid even a little more, he says, enough to make ends meet and maybe save a bit at the end of the month, it could help families send their kids to college, just like the children in those pictures on the desks he cleans.

Follow Krissy Clark at @@kristianiaclark