Some of Facebook’s cafeteria workers on Tuesday picketed at the social network’s downtown office in San Francisco, following months of negotiations over higher wages and a shorter work day.

The group’s union, Unite Here Local 2, says employees of food service operator Flagship Facility Services have to work multiple jobs to make ends meet in the nation’s highest-cost rental market.

These are workers who cook, serve meals and scrub dishes for employees of Facebook and its subsidiary, Instagram, at 181 Fremont, a new high-rise that is among the tallest in the city.

Delfina Ramirez, 24, ends her shift as a line cook at Facebook midday. Most days, she then spends five hours driving for Uber. She has a third job as a caterer on the weekends.

“I love my job, but the money is not fair,” said Ramirez, who moved from the city to Daly City to save money on rent. She shares a room with her 5-year-old daughter and rents the second bedroom.

Several dozen workers and allies, including a handful of people with Google and Facebook employee badges clipped at the hip, marched outside the building’s doors as the work day let out. They carried signs that read, “One job should be enough,” and chanted in English and Spanish.

“The cafeteria workers work really hard to feed the whole company every single day. They’re my friends and also my co-workers,” said Amr Gaber, an employee of Google. “It’s not right for them to be struggling to feed themselves or their families.”

“It’s entirely unfair,” added Wyatt Ratliff, a fellow Google employee. “Anyone working at one of these companies should be able to live comfortably in the Bay Area with one job.”

“We can do better, and we have to do better,” he added.

“We value our culinary team’s work immensely and continue to support the right of Flagship employees to unionize,” said Anthony Harrison, a Facebook spokesman.

Marion Terrell II, who leads human resources at the food services operator, said in an email that only a small number of Flagship employees and their union representatives organized the rally.

“Flagship is committed to ensuring a safe and fair working environment for all our employees, as well as having a positive and proactive relationship with our staff and union partners,” he said.

The operator has contracts across the country to staff mail rooms, reception, janitorial services and building engineering, but its only food services customer is Facebook, said a spokesman.

Flagship said it offered workers at Facebook’s downtown office wages and benefits that are “in line” with what other workers receive in Menlo Park, Seattle, New York and Fremont.

“To compare San Francisco to other facilities, we think, shows that they’re out of step with what’s needed here,” said Anand Singh, president of the local union chapter, citing the cost of living.

Nathanael Percastre, a line cook at Facebook, stepped outside during his break to join the demonstration. His face lit up when he saw the size of the crowd that had gathered.

Percastre, 43, also works two other jobs, selling his acrylic ink drawings at art fairs and doing catering work, to make ends meet. He spends almost $200 a month on his commute from Emeryville.

“It would be nice to live in the city where I’m working,” he said.

Delfina Ramirez is a full-time cook for Flagship at @facebook's San Francisco office - but she has to work three jobs to make ends meet.



RT if you agree that one job should be enough for Delfina and every worker who helps prepare food in Big Tech cafeterias. #1job #unitehere pic.twitter.com/0xkYBqfmTU — UNITE HERE Local 2 #1job (@UniteHereLocal2) July 15, 2019

If cafeteria workers do win higher pay and better benefits, it could have repercussions on local restaurateurs, who already compete with tech contractors for food service workers.

For years, cafeterias at tech companies like Facebook, Google and Square have drawn workers with steady pay and better hours than most restaurants. The jobs often come with health care coverage, a rare benefit in food service, said Kim Alter, chef and owner of San Francisco’s Nightbird restaurant.

She has to pay wages that compete with what the food service operators offer, a task that’s getting harder all the time.

“We don’t get as many diners as 10 years ago, because (the tech cafeterias) not only put out meals but package them” so tech workers can take dinner home at night, Alter said.

Preeti Mistry worked a stint as executive chef at the Google campus in Mountain View. It wasn’t a great fit for the chef, who later opened the popular Juhu Beach Club restaurant in Oakland.

“There’s always nice people and not so nice people, but ultimately, you have a certain amount of people within a tech company that, as they should, see the food as their benefit, just like health insurance or free parking,” Mistry said. “It’s taken for granted. It’s like, you’re here to serve me.”

She said she could afford to leave the tech giant because she and her wife don’t have children or a mortgage. Plenty of line cooks and dishwashers don’t have that privilege, she said.

Facebook’s cafeteria workers at 181 Fremont have been in negotiations since April for their first contract, after organizing with Unite Here Local 2 last year.

The union is asking for the work day to be shortened by a half hour to eight hours and an increase in wages. It also wants Flagship workers to have the option to join the union’s health care plan at no cost for individuals and a small copay for family coverage.

Unite Here, which was behind last year’s strike at Marriott hotels, has “set a standard in the places where their members work, in hotels and other establishments, that allow people to survive and support their families on the wages that they earn,” said Ken Jacobs, who leads the Labor Center at UC Berkeley. “That is what they’re demanding in this case — is that the standard be maintained.”

The workers could strike in the future if the union and operator fail to reach an agreement, Singh said.

“They’re part of the community in San Francisco, and they’re part of my company’s community,” said Gaber, the Google employee, of cafeteria workers. “If tech wants to talk about making the world a better place, it has to start with treating every one of its workers with dignity and respect.”

Melia Russell is a San Francisco Chronicle staff writer. Email: melia.russell@sfchronicle.com Twitter: @meliarobin