Why all that scaffolding on the State House? To avoid the mistakes made last time

  • The State House golden dome is partially hidden from the scaffolding. Gilding work will begin the week of May 16. ELIZABETH FRANTZ / Monitor staff

  • The State House dome is encased in scaffolding on Friday. The scaffolding atop the State House should be finished this week, wrapping up a year of preparation for the summerlong project to replace the gold leaf on the dome. GEOFF FORESTER / Monitor staff

Monitor staff
Published: 4/24/2016 11:49:23 PM

The scaffolding atop the State House should be finished this week, wrapping up a year of preparation and setting the stage for the summerlong project to replace the gold leaf on the dome.

Just getting ready for the job has taken months and cost roughly $1.3 million. That was to avoid problems that occurred the last time around, said Theodore Kupper, administrator of the Bureau of Public Works, who is overseeing the $2.8 million project. 

“The issue was how to have scaffolding on a roof that couldn’t support 30 feet of scaffolding the last time, and we want 90 feet of scaffolding, all the way up to the eagle,” he said.

As Kupper tells it, the last time the gold leaf was replaced on the State House, in 1993, workers reached  part of the dome by sitting in hanging bosun’s chairs suspended from beams stuck out of the windows of the cupola atop the dome, called the lantern.

While relatively easy to install and less expensive, this system made for slow work, which appears to have contributed to problems with the gold leaf. The gilding on the dome began to visibly flake off in recent years, but should have lasted a decade or even two decades longer.

The last time the work was done, Kupper said, workers stripped off the gold leaf then primed the copper dome and covered it with what is known as “size,” a material that adheres well to the gold leaf. Because of the slow work pace, however, the job wasn’t finished in time.

“It sat over the winter, and they came back the following spring and finished gilding,” Kupper said.

Winter wear on the under-layer helps explain why the gold leaf didn’t stick as long as it should have. An analysis by the state recommended the entire gilding process should be completed in a single season, which required much more extensive preparation.

“The only way to accomplish the goal of having it all in one season was to set scaffolding around the dome – to get multiple platforms of workers up there, and even more importantly, to get material flow up to the work areas and debris flow down in an efficient way,” Kupper said.

The resulting structure, built by Maine-based Seacoast Scaffolding using material from its Loudon Road facility, is huge. The scaffolding, workers and construction material will weigh almost half a million pounds.

That size poses a problem, because last time around some scaffolding was placed on the roof of the State House and, Kupper said, “Anecdotally we had learned that at least in a couple of spots the scaffolding had punched through the roof.”  

Yet the earlier scaffolding rose only about 30-feet the bottom of the gilded portion of the dome, and was much smaller than the current version.

Last year, workers built a structural steel platform atop the State House roof that rested on the building’s masonry walls. It required removal of two gable roofs on both sides of dome as well as lots of other construction. The platform sits around the very base of the dome and can support the half-million-pound scaffolding.

There’s one more complication – involving the wind.

“Scaffolding is an interesting product. Even without the safety netting, it’s basically like a sail,” Kupper said.

Scaffolding usually rests against the building, using cushioned pads called bumps, to keep it from blowing away. But the dome, a post-and-beam structure erected in 1819, basically just sits on top of the State House, Kupper said. It is attached by only 32 bolts.

“Our scaffolding couldn’t employ bumps. If it did and the wind came along, it could literally push the dome off the building,” he said.

Instead, guy-wires had to be built all around, connecting the scaffolding to the platform and holding it down.

If all goes as planned, the safety certification for the scaffolding will be finished this week.

After some maintenance work on the lantern, Kupper said, Evergreene Architectural Arts of New York City will come for preparatory testing and then begin the process of putting sheets of microscopically thin gold on the dome.

Work on the gilding is set to begin the week of May 16.

(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)


David Brooks bio photo

David Brooks is a reporter and the writer of the sci/tech column Granite Geek and blog granitegeek.org, as well as moderator of Science Cafe Concord events. After obtaining a bachelor’s degree in mathematics he became a newspaperman, working in Virginia and Tennessee before spending 28 years at the Nashua Telegraph . He joined the Monitor in 2015.



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