By Richard Bermack, Contributing Writer and Photographer
One thinks of cement masons pouring a gray, mud-like substance that they frantically rake and trowel to level and shape in place before it sets. But pouring the cement is only half the job. After it dries, they have to patch and grind until the surface is either aesthetically pleasing or functionally smooth – or both.
Now imagine a 100,000-cubic-yard slab of concrete that will be the floor of a train station serving 100,000 people a day and 45 million people a year. And then there are the walls and ceilings. And the train platform is only the bottom story of a five-story structure that is the size of four city blocks. That is a lot of concrete to pour and polish, and that’s the job of the members of Plasterers and Cement Masons Local 300 building the Transbay Terminal.
When we visited the Cement Masons they were patching and finishing the first layer of cement, or (Cement Deep Soil Mixing) CDSM. The CDSM covers the metal shoring and seals out the earth. A waterproof membrane is then applied over the CDSM, and then another layer of rebar and cement is applied over the waterproof layer, forming the interior wall and surface. The masons were working on the mat slab area of the train platform, where the trains will enter and exit the building.
Descending into the mat slab area is like walking into a vast, dark, cement cavern. The ceilings are 30 feet high, supported by Roman columns and a forest of steel scaffolding and trusses. A cement mason suspended 20 feet in the air on a lift, wearing a head lamp, chips and patches a cement beam. Except for an occasional beam of sunlight from open areas, the only light is from electric work lamps.
A freight elevator takes us out of the mat slab area and into the open air. This will become the second floor of the terminal. Cement masons are scrubbing the CDSM layer on the shoring walls, while iron workers weld plates on the opposite side of the pit.
The Transbay Terminal is a joint venture of Webcor/Obayashi, and the cement masons work for Shimmick Construction, one of the subcontractors.
–Voices From the Union–
This job has been stressful but maintainable. There’s so much congestion with all the trades working in the same spot. To move materials from one side of the job to the other has to be pre-planned almost two days ahead.
Safety is a big thing out here. You have a lot of different trades working in the same spot, so you have to be really mindful of what’s going on around you. You not only have tripping hazards from all the people working on the ground, but falling debris from people working on the overhead structures. You have iron workers working on the beams and cement masons working on the columns and the ceiling. It takes a lot of communication, which is why we have radios and make sure everyone is wearing the proper PPE.
Every morning we have a safety meeting where we do a job watch and job hazard analysis. Timing is everything, and you have to stay on schedule. So far we are doing a good job.
At this point we are working on the dry finish, which involves a lot of grinding and patching, fixing the imperfections in the concrete and cracked tiles. There’s over a million square feet of concrete surfaces. That’s a lot of finishing.
When they strip the forms from the walls you have rock pockets and chamfers missing, and wall deflections where the pour pushed out. We skim coat with rapid dry cement and use chipping hammers, chipping guns, and grinders. We have to make the surface perfect, so the waterproof membrane can go on over it.
One of the challenges has been access to the high walls. Everything has to be done on a sky boom and aerial lifts. The ceiling for the mat slab is 30 feet in the air, and we have walls that are over 40 feet tall.
Another danger is the darkness. As you go further down the mat slab it gets darker and darker. You need headlamps to see the work, and then you have people driving forklifts and on lifts. It takes a lot of mindfulness.
Every morning I get the apprentices together and ask them, “What’s your goal for today?” I try to instill in them self-motivation. Every now and then I have to light a fire under them, but I do it the right way. If you give people a lot of compliments they are more receptive to criticism. So before I give them any type of criticism or motivation I give them compliments and let them know they’re doing good, and that way they will want to exceed what they’ve already done and will take suggestions in a positive way. I got it from this book, How Full is Your Bucket?, by Tom Rath. It’s a great book. I recommend it to all foremen and anyone who manages people.
The best part is finishing the concrete. You just keep it at a creamy consistency and when it dries it looks nice and smooth. Then you go over it with your trowel and it seals the concrete. It seals all the holes so no air can get through and cause bulges. If it’s not smooth and level, the concrete will break through the waterproofing.
I enjoy the work. They keep me busy all week. I did a pre-apprenticeship when I was in high school and then got in the apprenticeship program with a bunch of my friends.
Today I’m patching the ceiling. It can be a little scary up on the lift, being way up there. Occasionally it will start shaking, and sometimes you wish you were back home. But it’s okay. We work safe and it’s my job. I like doing the finishing on the floor best. It’s nice to have your feet on the ground. But it’s fun being up high too. You get a little bit of adrenaline.
I worked on the Dumbarton Bridge, on the columns over the water. I told my wife about it and she got nervous. But she was proud that I did it.
It’s awesome. I’ve been at this project for two years. I like all the handwork and the finishing work. I like making things look good. Right now they have us doing the CDSM patching for the waterproofers. The excavated walls have a bunch of holes and rocks in them and we have to come through with mortar and patch them and make them smooth so the waterproofing doesn’t get popped.
I’ve been working up on the lift. It took me a few months to get used to it. I was a little nervous at first. Before they built the second level we were going up about 45 feet high. It was kind of scary, but then I got more comfortable driving the lift and feeling secure that it wasn’t going to tip over.
I was in Fresno without a job or a home, and then I found out about the Job Corps. They took me in and they trained me. You got to try different trades. I picked cement because I was best at it and it was the most fun.
You can take a trowel and make the concrete finish look exactly how you want it. I like the burner trowel, it’s a lifesaver. You can fix almost anything with it as long as the cement is not 100 percent dry. It’s a hard, small trowel, and you can use a lot of pressure on it to fix any little holes.
I was pretty desperate. I did this as a last resort. I never had any idea how much I would love it. It changed my life.
How is it working in the trade as a woman? I’ve never had any problems. I just work my butt off and everyone accepts me.
I’m patching and grinding the wall. It’s pretty easy. First you fill the holes, the little ones and then the big ones. Then you take the little grinding machine and put it right on the wall. You just need to keep the grinder flat, and then it looks great when you’re finished.
My favorite jobs are the big slabs. You can spend days working on them. You just start at one end and then keep going until you get to the other end.
Today I’m patching. I like making a nice flat surface. But I like everything else about concrete, too. Concrete is everywhere, sidewalks, streets, walls. Everything you see when you walk around is made of concrete, and you know that you make that.