SAN FRANCISCO (KCBS) — More than 1,000 unionized construction workers walked off the job Thursday at the UCSF Benioff Children’s Hospital in Mission Bay. The workers are upset after six non-union construction workers were brought on the job on Wednesday.

The bulldozers and other tools at the 16th and 3rd Street location have gone quiet while union representatives and L&S Refrigeration work to find a resolution.

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Steamfitter Greg Hodges said between 1,000 and 1,300 workers walked off the job. “It started out three guys, suddenly they have six guys,” Hodges said. “What’s it going to be tomorrow, 12 guys?”

Retired plumber Lyle Shiffer with Local 38 is walking the picket line. “Let’s get this straightened out. It’s going to be join the union or get off the job,” he said.

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No immediate decision is expected on Thursday, but construction workers may be gaining more clout in an improving economy for their industry.

Union plumbers who were on this job had no trouble finding other work for the day given the construction boom.

“The fact that the economy is improving for construction in particular gives people the confidence to act in what they view as an issue of principle,” said UC Berkeley Professor Harley Shakein, who specializes in labor.

According to UCSF, the new Benioff Children’s Hospital is scheduled to open in February 2015.

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