A Beautiful Dialogue Between Materials

Soon to be dedicated, Green Hall is the latest of the stately structures that dot the university’s Danforth Campus. The Collegiate Gothic buildings exhibit excellent stone workmanship and the exquisite interplay of Missouri red granite and Indiana limestone.

Green Hall exhibits the exquisite interplay of Missouri red granite and Indiana limestone. To be dedicated Sept. 23, it’s the latest of the university’s stately Collegiate Gothic buildings. (David Kilper)

In Missouri, granite is plentiful, old and red.

Durable, too, says Neal T. Schaeffer, project manager in the Washington University Department of Facilities Planning & Management.

“When you are building something for a lifetime of 200 years and beyond, you’ve got to use that kind of material,” Schaeffer says. “That’s our goal, 200 years for a building’s exterior. And, after that span, the granite will still be there.”

Preston M. Green Hall — scheduled to be dedicated in a ceremony on Sept. 23, 2011, in front of Brookings Hall — will house the School of Engineering & Applied Science’s Department of Electrical & Systems Engineering, plus researchers from the International Center for Advanced Renewable Energy and Sustainability (I-CARES). The building, named in honor of the late Preston M. Green, a WUSTL alumnus (BSEE ’36) and benefactor, turns the corner at Skinker Boulevard and Forest Park Parkway, connecting on its western edge to the recently completed Stephen F. and Camilla T. Brauer Hall.

Waiting for granite

The source of the granite for Green Hall — the engineering’s school’s latest LEED-certified Gold crown jewel nearing completion after a frenetic eight months of construction — is the Missouri Red Granite Company. Nestled in Iron County, Mo., some 100 miles southwest of St. Louis, the quarry is on the backside of Elephant Rocks State Park. Elephant Rocks is a curious amalgam of igneous rock pushed from the Earth’s interior to the surface more than a billion years ago and that resemble elephants. The font of the granite is an enormous pit, the centerpiece of a mine consisting of approximately 100 or so acres, set in gentle Ozark hills.

“It’s a huge hole in the ground with ramps for big trucks and coal mine-sized forklifts to go in and out of there,” says Frank Freeman, Schaeffer’s colleague and fellow WUSTL project manager, who has been vital in the planning and construction of about a dozen university buildings over the past 20 years. “Workers cut the stone with big gas torches and haul out pieces about the size of a small bus. They split them into smaller pieces and ship them east, where the slabs are sawn into pieces that we use in the buildings.”

The granite “finishing factory” involved in the Green Hall project is North Carolina Granite, which employs specialized, heavy-duty equipment that splits the granite into blocks roughly four to five feet wide, eight to 10 feet long. After North Carolina Granite finishes its order, the granite is hauled back in semi-trucks to Missouri Red Granite where it awaits the call from Freeman and Schaeffer and the building project’s chief masons, Steve Schulte and Brad Kasten of Leonard Masonry in St. Louis.

That’s a pretty long haul from extraction to emplacement on the WUSTL campus, but it’s a drop in the geological bucket in comparison to how long the fine, stout stone that graces the campus took to reach the Earth’s surface.

Building on course

According to Robert Criss, PhD, professor of earth & planetary sciences in Arts & Sciences, granite is an igneous (from the Latin ignis, or fire) rock, forged out of incredibly hot (more than 1300 degrees Fahrenheit) magma. Similar rocks form the foundation for Earth’s continents, and some granites are nearly as old as the Earth itself, dating back four billion years to the early Precambrian. Magmas crystallize as molten rock gradually rises and cools near the Earth’s surface, creating igneous rocks. Granite is among them and is composed chiefly of feldspar and quartz. The granites in Missouri formed beneath a large field of volcanic rocks, much like that at Yellowstone Park, which formed when some of the magma erupted at the surface. The stuff of everything from kitchen counters to street curbs, to buildings and presidential monuments (i.e., Mount Rushmore), granite is the mainstay for buildings on the WUSTL campus. In Green Hall alone, there will be 100 million pounds of granite in the walls and floors, fashioned in a style known as Collegiate Gothic.

Long after Missouri’s granites crystallized, great layers of limestone formed in the American Midwest during the Mississippian period, somewhere between 359 and 318 million years ago. During some of that time, Criss says, much of the region lay under a shallow ocean. A sedimentary rock made up primarily of calcite (CaCO3), limestone, and its variations, can be formed by either chemical deposition or by the accumulation of shells from tiny sea creatures. The type of limestone in Green Hall is classified oolitic (the namesake of a limestone-rich town in central Indiana), and it makes up slightly more than 100 million pounds of the building. Hailing from the Indiana Limestone Company, it serves as a complement and frame to the granite. (Limestone is famous in central and south central Indiana. In fact, one quarry there is named Empire Quarry, because limestone from that quarry was used in the Empire State Building.)

“Probably one hundred times more thought is actually put into the limestone than the granite,” says Schulte, the chief mason who oversees a crew of 28, including 18 masons and 10 other assistants and equipment operators. “Every piece of limestone has to have a predetermined height and width. The granite for the most part is the filler.”

The granite, Schulte says, drives the size of the limestone, which goes in at the building’s perimeters, called “quoins,” and at windows.

“You put the limestone in before the granite, and then the granite ‘fingers’ in to those sides of the limestone that were pre-cut to make the granite coursing,” says Schulte, who has been a key mason on numerous WUSTL buildings since 1992.

Jim Garrison, of Frens and Frens, LLC, in West Chester, Pa., is the lead architect for the exterior envelope of Green Hall, as he was for Brauer Hall. He explains coursing as the backbone of the design consisting of a horizontal grid based on the smallest piece of granite plus a mortar joint applied to the face of every square foot of the building. In thinking of bricks, three layers of bricks stacked equal 8 inches, and one course of concrete block is 8 inches. The granite modules come in three sizes, approximately 3, 6 and 9 inches.

Garrison runs the design on powerful computers working closely with the stone suppliers to provide coordination from the outset of design. “If we weren’t using computers, we’d go crazy tracking it,” Garrison says. “The university, working with Leonard and other architects over the years, has developed an ‘ace’ modular coursing system with the granite, where a + b = c (3, 6, 9 inches). This system allows for the three different modules that can be mixed and always ‘coursed out,’ so the granite and limestone windows and doors can align just right. This modular system creates a somewhat random appearance in the wall, all the while controlling the dimensions. And if you look at the walls, you start to see the rhythm in it, but it doesn’t jump out at you, which is the effect we want.”

Garrison says the Brookings Hall quadrangle, with its mix of historically inspired designs, served as the inspiration for the engineering complex in general during the master planning phase with RMJM Hillier in 2007. Brookings Hall is the loose model for Green Hall.

“I think that people wanted to get away from the notion that the engineering quadrangle should be one big, overpowering building,” Garrison says. “Instead, it should have a sort of evolutionary quality about it.” The sources for this Collegiate Gothic architecture come from the palaces of King Henry VIII or Queen Elizabeth I. “We wanted something that had enough presence to anchor this corner of the campus, but we didn’t want it to appear too palatial,” he continues. “We’ve been able to adapt the stone details that occur on the oldest buildings on campus and also some of the new ones — Anheuser-Busch Hall and the [Charles F.] Knight Center — to work with the different historical styles that inspired the original campus architects.”

The architects and masons really work hard to have the granite appear that it just came out of the quarry – with a natural split finish and a certain irregularity about it. “There’s a contrast between a softness and crispness in the limestone with the quarry face in the granite that sets up a really beautiful dialogue between the materials,” Garrison says.

Maintaining a look

As for the famed “Missouri red granite,” the color has ranged in recent buildings from a more uniform red to softer shades of purple, and even pink. The color can be affected by water in fissures, and the granite that is in contact with water for a long period of time turns to a yellowish-orange that is referred to as sap stone.

“We want to keep the color within a certain range, but when it starts to get the sap stone look, the operators cut the discolored portion from the blocks and dispose of it,” Freeman says.

Basically, Kasten says, it’s classic Missouri red, between a medium and dark color.

While WUSTL has partnered with Leonard Masonry often over the past 20 years, it’s not a “done deal” that Leonard will get the masonry contract for each new campus building, nor that Missouri Red Granite will get the stone contract.

“We bid the granite and limestone as well, so it’s all very competitive,” Freeman says. “In the case of the Psychology Building, for instance, erected in 1995, Cold Springs Quarry in Minnesota had the low bid, and in the past we’ve also used Granicor, a quarry in Canada.”

The team of Freeman, Kasten and Schulte has been key to the Danforth Campus look and feel for two decades, and “they’ve been highly instrumental in putting the coursing and other standards together that make everything work,” says Schaeffer, who joined the university six years ago.

“Every building has its charms and idiosyncrasies, and with every building, we learn something new,” Freeman says.

Tony Fitzpatrick is a freelance writer based in St. Louis.

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