A Natural Way to Clad the Lab

“It was a very challenging project, and we enjoy projects that push us to new levels and that show different qualities and different kinds of movement in the stone,” says Ballif. “We look for opportunities like that. And, because of our relationship with Delta, it fit together.”

And, he says if one of the other masonry companies had offered a lower bid, Delta Stone would still have provided the stone for the project. Its location near the building site and its hardness were features that enhanced the project, regardless of the installer, Charves says.

Click photo to enlargeBallif says that Delta’s quarrying process began even before serious work began on construction.

“We were hoping to be in a place to sell the stone to whoever might install it, so we started producing it in anticipation of that,” he says. “Also, much of our stone sits in a different style quarry from most of them, and we felt we needed to start early.”

He explains that the bedding planes for the stone are at a 60° angle, so the stone is pulled out as boulders and then processed. Much of the cutting was done following the natural seams, which accounts for the variety of heights from 2” to 9”.

Delta utilized three guillotines on its site, ultimately shipping 350 tons to the project.

The installation by RJ Masonry involved random courses in an ashlar pattern within certain specifications.

“The pieces couldn’t be any longer than 30”, and joints had to maintain a ½” to 5/8” thickness,” Ballif says. “We also had some different expansion joints and vertical drift joints that we had to hide. And, part of the whole process was the membrane that had to be put on before the bracket-and-tie system we were using. It was interesting to make it all come together.”

Prescott Muir’s Robertson explains that the structural system is 16-gauge steel studs supported by a concrete frame structure. The studs are clipped off the slab edges, and then there are steel relieving angles and lintels welded to the steel studs, with the material being laid out on the lintels.

“Because we have random coursing, the ties couldn’t be installed ahead of time at defined locations,” says Robertson. “They needed to be adjustable so they could slide up and down to match whatever coursing they were nearest when we came to the overall schedule of tie spacing. It utilized 7/16” stainless-steel rods set into clips or threaded through clips at a predetermined location; then there was an adjustable tie that slid up and down the stainless-steel rods to locate in the courses wherever it worked out in stone.”

All of the stone had a nominal depth of 3” to 4”, he adds.

Ballif says that RJ Masonry had a crew of up to 28 masons on the job, starting in October 2010 and working through mid-February to install approximately 21,500 ft² of stone. Because of the season, the work was tented to maintain temperatures for the curing mortar.

Wind, rather than temperature, proved to be a challenge at the site more than once, adds Ballif. The other big challenge: On some parts of the building, the installation began 20’ to 30’ above grade.

“I also spent a few times walking up scaffolding with Jack (Robertson) to make sure we were on the same page,” Ballif says. “Trying to do an ashlar pattern and do a mix before they had a clear idea of what they wanted, plus working with Mother Nature, was a challenge.”