A “Capitol” Investment

An earlier version of this article originally appeared in the Spring 2024 edition of Building Stone Magazine.

The restoration of 515,000 square feet of exterior limestone at the Missouri State Capitol required more than five years to complete. Photo by Trivers

Of all the stone buildings constructed in the United States, state capitols reach a level of grandeur that serves as a testament to their symbolic importance. Often emulating the most ornate styles of the last two thousand or so years, a state’s seat of government may feature columns, dentils, friezes, hand-carved sculpture, modillions, and all sorts of cherubic or godlike ornamentation, suggesting that the deities of old and their many minions are watching over the proceedings inside. 

Even with ancient gods looking on, however, buildings tend to age. The ravages of a century of wind and weather had taken a toll on the Missouri State Capitol in Jefferson City, so much so that visible signs of water damage had come to the surface. High atop a bluff of the Missouri River since construction began in 1913, the capitol’s marble façade required comprehensive repairs to maintain safe conditions for the people who work inside. The state government also intended to preserve all of the features that make the capitol such a grand edifice—the sculptures and ornaments that gave the building its gravitas. 

A full inspection revealed that every inch of the capitol’s 515,000-plus square feet required restoration, a program that would take half a decade to complete. The state assembled a team of general contractors and skilled craftspeople to begin the process.  “We approached this from three different angles: safety, water infiltration, and aesthetics,” said Joe Brinkman, principal with Trivers, the St. Louis-based architectural firm selected for the project. “There was some stone on the exterior that was so unstable it was at a risk of falling. Over time, joints had opened up where stone had cracked, and it was allowing water in. And the whole building needed to be cleaned and repaired, some of it within easy eyesight of people on the ground.” 

Trivers partnered with the engineering firm Wiss Janney Elstner Associates (WJE), who conducted a meticulous, year-long inspection and determined the extent of the work required. “They actually rappelled down the building on ropes and looked at it closely,” said Brinkman. “Every stone was numbered, and there were certain prescribed repairs for each stone. Some just needed to be cleaned. Others needed to be replaced. And some percent of the building close up,” said Laureys. “We got quantities based on a quarter of the building, we used some engineering judgment. We had our staff tapping on every stone—and then we prioritized, we juggled the amount of repairs in the job and communicated that to the owner. We use PlanGrid [construction management software] to document every piece electronically, and we take pictures. The contractor then has immediate access to the program, and we can track everything.” 

Some of the ornamentation required extra protection from the elements, like the cornices at the overhangs just below the capitol dome. Photo courtesy Ross Creative Works

“Like We Were Never There” 

As the restoration got underway, the bulk of the work went to Bulley & Andrews Masonry Restoration (BAMR), a Chicago- based company. Year-round work meant that the crew began by wrapping the scaffolding in plastic, allowing them to heat the space in winter and air-condition it in summer. “We had twenty to thirty tradesmen on it every day,” said Chris Thomas, Project Executive with BAMR. “But keeping things on schedule was tricky. The logistics of getting the right pieces at the right time was a three-year headache. We had to make sure the trucks arrived when we needed them, and that the right pieces were on the truck.” 

The meticulous carving of 8,000 pieces to match the originals took place at Gary Galassi Stone & Steel (GGSAS), BAMR’s accustomed partner in Romeoville, Illinois, near Chicago. “We did everything from traditional planers, which will run the standard, simple profiles, to full five-axis milling using CNC machining,” said Chris Galassi, who heads GGSAS. The computerized system allowed the company to create dozens of identical pieces to replace the exquisitely detailed original carvings. “We have three in-house hand carvers who can take a rough block of stone all the way to the modillions on the building,” he said, but most of the larger pieces required the absolute precision of the CNC process. 

The three-year project grew in scope by fifty percent over time, Galassi said. “It was pretty substantial in terms of turnaround times,” he said. “We were working with Phenix Marble to get raw materials out to our facility, making sure that everything had gone through quality checks, so it was consistent and uniform. Bulley & Andrews wanted a load on site every Friday to set up for the following Monday, so we were taking a full semi load, 45,000 pounds of finished product, every single week.” Equally impressive was GGSAS’s 100 percent accuracy rate: every one of the 8,000 pieces delivered was installed on the building. 

Even with this extraordinary volume, however, GGSAS brought the project to a close six months ahead of schedule, delivering the last piece two and a half years after they began. “We were able to keep up with the high product demands because of our relationship with the restoration company and the quarry,” said Galassi. “There’s kind of an understanding there of what it entails to go through one of these projects.” 

In addition to the carving process at GGSAS, BAMR’s crews had the ability to retool pieces in place if the finish had come off the face of a relatively intact section of existing stone. “We had specialty carving tools on site, so we could sometimes make the old piece look new again,” said Thomas. “That was mostly the flat pieces. The more detailed pieces—once those go, you can’t repair them, so they were removed, and new pieces were installed to replace them.” Above all, the emphasis was on replacing the original exactly as it had appeared for the last century, said Thomas. “It’s a national landmark, so our goal always is to restore the building and make it look like we didn’t do anything, like we were never here.” 

The BAMR crew managed several onsite repairs that included the use of dutchmen—and even this common technique ran into obstacles. “Normally a 3/8-inch joint is standard for a dutchman,” said Thomas. “But for this, we couldn’t have a joint larger than 1/8- inch. There was not a lot of tolerance. So, the dutchmen were difficult.” Even with all of the planning, numbering, examining, and recording, however, some issues did not reveal themselves until the building was surrounded by scaffolding and workers could lay eyes on every piece. “Sometimes we’d remove a piece and find there was more extensive work to be done,” said Brinkman. “We did a replacement of the terraces around the building, and we couldn’t tell what was underneath until we were into the construction process and had to peel it all back. The extent was a little more than we expected during the initial investigation. But nothing was a big surprise.” 

Once the new stone replaced the old, crews applied fresh mortar throughout to hold all of the pieces in place. “The original mortar joints had all been ground out, probably in the 1990s, and they had installed sealant instead of grinding the joint out and replacing it with mortar,” said Laureys. “For us, sealants are a big NO for a monumental historic building—sealant fails over time, and it can trap and hold the water in longer. Since they put in sealant, it makes it harder to put in mortar, because it creates a bond break—the mortar won’t bond with the stone. It’s more difficult than standard grinding and rebinding. We always test the mortar, you always want to go back with something a little softer than what was there.” 

Using the 3D model, WJE created elevations that served as instructions for repairing the lantern. Photo courtesy Wiss Janney Elstner Associates

Restoring the Lantern

Atop the capitol’s crowning dome— more than 400 feet up—a marble “lantern” provides the base for one of the state’s most enduring symbols: a bronze statue of Ceres, the Roman goddess of agriculture. Like the rest of the building, the lantern showed signs of significant wear, and Thomas and his team knew that it needed rebuilding. 

Thanks to modern imaging techniques, however, BAMR did not have to remove the lantern from the top of the dome. “We used reality capture, laser screening, and drones to create a 3D model,” Thomas said. “Then we disassembled the lantern in place, scanned it all again to see what was inside it, and put it together on a computer. We sent all of that off to the fabricator. So instead of taking it down and shipping it to Chicago, we did it all digitally. It saved lots of time.” 

Meanwhile, Ceres got a makeover that enchanted the entire state. Lowered from her lofty perch by a massive crane, Ceres’s arrival at street level attracted crowds and media attention. “Everyone got to look at the statue up close and touch it, because when are you going to have a chance to do that?” said Thomas. “She even had her own Twitter account, so when the project started, she was tweeting the whole time about how they were cleaning her up: ‘Got a bath today! At the spa!’ and so on. That was a pretty big milestone for the project, seeing her go back up to the top.” 

The return of the statue signaled the completion of a project that had seen the state’s capitol wrapped in scaffolding and plastic sheeting for more than three years. When it all came down, the finished building looked extraordinarily as it had back in 1917. “That was our goal—we didn’t want to make any changes,” said Brinkman. “We weren’t trying to improve it, we were working to preserve it. It’s a compliment if people say they don’t even know we did anything. It was 100 years old when we did this, and hopefully we’ve given it its next 100 years.” 

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