JobSight: Target Field, Minneapolis
“About 70 percent was what we call a natural strata material – the top of the block,” says Ron Vetter. “About 30 percent had a honed finish for the horizontal accent bands on the exterior. On the interior, most of the stone is honed material.”
While Vetter dealt with those issues, Kelley says Gage Brothers’ biggest concern was joint sizes.
“The precast-to-precast joints needed to be 3/4”, due to the 7’-9’ X 21’ X 10” thick size of the panels,” says Kelley. “However, sometimes stone-to-stone joints are smaller. We really pushed for all the joints to be 3/4” so the wall would not look panelized and, more importantly, to maximize our erection flexibility.
“The weight we could pick up with the crane varied greatly by panel location. Keeping all the joints the same size allowed us to execute this and give the architect the look he wanted everywhere.”
Kelley says, to help clarify the issue, Gage Brothers made two mock-ups, each with eight panels and approximately 20’ X 25’ to demonstrate both a 1/2” and 3/4” stone joint for the owners and architects.
“They spent some money on that, but they wanted to get it right,” he says.
TIMING IS EVERYTHING
With those details ironed out, the exterior casts took 50 weeks, according to Kelley, who adds that his company assumed the lead on the drawings.
To make things easier to handle, the work was divided into eight sections, starting in what would be the ballpark’s right field and working clockwise around the stadium.
“We got the architects’ drawing here, and then we would start to panelize and layout the stone within the parameters Vetter Stone and the architects gave us,” he says. “We’d get one area laid out with the stone jointing the way we thought would work best.
Then, we’d send the drawings back to the architects to okay the layout of the stone. They’d send them to Vetter, so it could start making the stone.”
While that was going on, Kelley adds, his company figured out how the panels would connect to the structure, and then submitted that information.
Further complicating that part of the process, he says, is that the project was on such a fast-track schedule that the exterior elevations were being completed not very far in front of the stone panels.