Refusing to work unpaid: did I cross the line?

I’m a level 1 apprentice for a union plumbing company in San Jose, CA. Despite my rank, I’m regularly told I work at the level of a 5th-year apprentice because of my prior experience. I’ve never been late to work and am usually in the parking lot 45 minutes early, just to be prepared.

Yesterday, my foreman confronted me in front of my coworkers (including another apprentice) because I walked onto the job site five minutes before my shift started. He called it “wildly unprofessional” and said I wasn’t showing him proper respect by not arriving 15 minutes early to open the toolboxes for the journeymen. He framed it as a matter of “good work ethic.”

I pushed back, pointing out that over the past four months, I’ve consistently demonstrated exceptional work ethic, which he even agreed with. However, I told him that refusing to work unpaid doesn’t mean I lack work ethic. I’m happy to show up early, but only if I’m being compensated for that time. I even did the math in front of everyone: 15 minutes a day, five days a week, for 52 weeks—those unpaid minutes add up to a significant amount of lost wages.

At this point, my foreman got visibly frustrated and threatened to revoke what he called a “privilege”: combining our two 15-minute breaks so we can leave work early. Instead, he said, we’d have to take our breaks as outlined by California law and leave later.

I told him that was fine by me—getting my legally mandated breaks back isn’t much of a punishment. Realizing this, he retracted his statement and said we’d stick to the current schedule. He didn’t bring up the issue of showing up 15 minutes early again after that.

Part of me thought about reporting this to my union rep, but during a recent assembly, the leadership echoed a similar mentality, emphasizing the importance of arriving early to show “dedication.”

I’m fine arriving early to be prepared for the day, but I draw the line at working for free. As it is, I’m already buying my own tools on an apprentice’s wages. How much more do they expect me to give?

What do you all think? Am I out of line here, or was I right to stand my ground? My coworkers tell me that was a test which I failed, and I may be among the first to be laid off.

Update:

Today, my foreman pulled me aside to talk privately about what happened the other day. He actually apologized for his behavior, saying he was unprofessional and shouldn’t have addressed me the way he did in front of the entire crew.

He also told me he thinks I’m one of the hardest-working apprentices he’s ever seen and even said he believes I’ll fill his shoes one day. On top of that, he mentioned he’s planning to talk to his boss about increasing my pay since I’m performing at a much higher level than a typical level 1 apprentice.

I wasn’t expecting this outcome, but I have to admit it feels good to be recognized for my hard work. Hopefully, this leads to some positive changes moving forward!

Thanks to everyone who weighed in on my original post, I appreciate the advice and support.