A thick, chemical smell mingled with the already pungent potpourri that arrested the senses of Mission Street sidewalk commuters where Dan Danielson and Jose Medina appeared to be painting the sidewalk on a recent weekday morning.
A few passersby had to be reminded to watch their step; the dark patches were wet with epoxy, the source of the smell.
Danielson and Medina, a terrazzo worker and terrazzo apprentice, respectively, explained they were laying a fresh layer of the lacquer sealant over an abstract terrazzo artwork inlaid in the cement near the Wells Fargo branch at 2595 Mission St.
This is only the second coat of sealant over the piece in its 22-year lifespan. “The sealer stays in there pretty much forever,” said Danielson.
He delved into the history of his profession, fascinated by its origins in ancient times and places like Italy and Greece. “Basically, back in those times when they used to do the marble statues, all the marble pieces would fall and they would use the small pieces for their walkways,” he said. “Then they would get stones to grind and smooth [the surface] because everyone was barefooted. That was kinda how the mosaics got started.”
Whereas mosaics are “small pieces of marble that were set individually in the cement,” he clarified, terrazzo requires materials, such as marble or other suitable substances, like quartz, to be ground ground into smaller pieces. The pieces are then mixed with binding agents, poured into place and sealed with an epoxy resin.
Today, electric grinders are used, but in the past, materials were hand ground.
Danielson was trying to find an old picture he had saved on his phone of workers hand-grinding for the floor of the Smithsonian’s United States National Museum building at the turn of the 20th century. “Everybody had these big long sticks with stones at the end, and that’s how they ground it,” he said, “I can’t imagine how they did that.”
He also had pictures of his work on the Salesforce Transit Terminal floor (425 Mission St.) in 2019. An artist designed the piece, and terrazzo workers like Danielson laid 30,000 square feet of “epoxy terrazzo,” depicting plants, birds, and geometric figures.
Danielson was proud of his contribution: “It got Job of the Year across the United States, actually.”
There were pictures of personal projects he completed for his home, too: a terrazzo floor in the garage, a terrazzo compass on the sidewalk out front, and the bathroom — all terrazzo. “Yeah, we get pretty involved,” he said, laughing.
Danielson lives in Benicia and has been doing terrazzo for 37 years. He got involved by joining a bricklayers’ union, and Medina, a Vallejo native who is newer to the craft at just four months in, is completing an 1,800-hour apprenticeship with the union. His on-the-job training will take about two years to complete, Medina said. They work all over northern California with Associated Terrazzo.