Harvard employee Newton Christian DeJesus on strike in Harvard Yard on Nov. 17.

Hundreds of custodial workers at Harvard University went on a short-term strike Monday, walking out of their jobs and gathering in Harvard Yard over frustrations with their salaries.

Strikes will continue through Tuesday evening at Harvard Business School and Harvard Medical School in Boston, including workers employed directly by Harvard and through contractors C&W Services and ABM Industries.

Contract negotiations broke down last week after Harvard wouldn’t budge on wage increases. They had been bargaining since Oct. 7.

“I am feeling disappointed, you know why?

Because I [have] worked at Harvard 13 years,” said Newton Christian DeJesus, who lives in Medford and was at Harvard Yard Monday morning. “I have a family, I have a wife, I have a daughter. I have to do this.”

The union that represents the 800 workers, 32BJ SEIU, says that Harvard’s offer of an annual salary increase of 2.2% doesn’t address the cost of living and the worry about inflation increasing expenses for everyone. Union representatives say custodial staff currently make $28 an hour.

“When we’re going to the market, everything is expensive. So, we work hard at Harvard, right? ... It’s a hard job,” DeJesus said. “We need more money. We need more assistance.”

In a statement to GBH News, a Harvard spokesperson said that they are working to make sure campus operations aren’t disrupted and are looking for ways to come to a fair contract.

“Harvard’s custodial workers are valued members of our community who enable teaching and research in critical ways,” the spokesperson said. “In light of current financial challenges and ongoing uncertainty around our financial picture, the University offered custodial employees distinct choices in how we approach compensation agreements: a short-term contract extension combined with a bonus, or a longer term extension that includes a combination of bonuses and modest, market-oriented wage increases that are guaranteed in future years.”

Maria Ahmad, who works on the cleaning staff at Harvard Law School, said it is especially important now as life in the Boston area has become more expensive.

“Please give more salary for the people because the situation now is more bad than the other years,” Ahmad said in Harvard Yard on Monday morning. “It’s very beneficial for everyone.”

Harvard has been under pressure from the Trump administration this year, facing legal challenges and uncertainty about funding. But Elena Lavarreda, janitorial division director at 32BJ SEIU, said that Harvard’s workers backed the university when it was being targeted and the university must now get behind its workers.

“While we disagree with what the Trump administration has done, the consequences of that can’t fall on the backs of some of the lowest-paid workers on campus,” she said.

Since the pandemic, Lavarreda said there has been a growing awareness about the importance of custodial workers.

“There are folks here who worked through the pandemic, people who got incredibly sick. ... They keep the school clean, and that is one of the essential functions of Harvard — not only is teaching young minds, but also they live here and they need to be safe and not get sick,” she said. “What the janitors do is an incredibly essential function, and they know their value.”

Meghan Smith is a senior digital producer on the Equity and Justice team for GBH News.