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A Project's Ups And Downs

Portion Of The New Science Center Roof Taken Off For Repairs

By JEFFREY B. COHEN, The Hartford Courant

December 01, 2007

The dramatic, sweeping roof that symbolizes the singularity of the Connecticut Science Center has provided the center's builders a little extra drama of its own.

Four months after the building was topped off, the roof has turned out to be a pain in the center's topside — the ends of the roof that extend beyond the building's eastern and western walls are sagging.

On Friday, a giant crane lowered a large section of it back to the ground, the first stage in what could be several weeks' worth of work to get the bugs out of the "magic carpet" roof.

Science Center President Theodore Sergi described the process of how the roof sections would be lowered, examined, fixed if need be, and lifted back into place.

"Anyone who's been involved in any construction project — Barbara Sergi building a garage on the back of our house — runs into problems," said Sergi. "This is an iconic roof on an iconic building, and you work through the problem. And that's what we've been doing."

The roof issue is a highly visible but not project-threatening glitch at the heart of the city's hoped-for downtown rebirth, a process that has moved fitfully — the Connecticut Convention Center is up and running, but construction on the nearby retail and residential space called Front Street won't begin until springtime.

It's not clear just who is to blame for the unintended roof sag: The architects, their engineers, and the construction manager blame the steelmakers and erectors, and vice versa. The issue isn't just pride, but money and who might end up on the hook. Sergi, however, said the cost won't be borne by state taxpayers. The $150 million project got $107 million from the state and the rest from the federal government and private donors

"This is not a project where somebody said, 'I did the job, goodbye,'" Sergi said. "Everybody's still on the project, they're at the table, and they're fixing it as we speak."

The science center held a "topping off" ceremony in mid-August to commemorate the installation of the building's final piece of steel. But by the end of the month, the center's quality control inspectors noticed the sagging roof. The eastern sag was more dramatic, and the roof did not have its intended structural strength.

Letters throughout much of October and November show a clear disagreement on exactly how the problem arose. Structural engineers at Thornton Tomasetti Inc., working for Pelli Clarke Pelli Architects, say, among other things, that the roof was unduly stressed, causing sag, because the contractors who put it up did so before attaching several steel plates. The construction manager, Whiting-Turner, agrees.

But the erector, Berlin Steel, says it raised the roof just as spelled out in the contract documents, and argues the problem could be attributed to flaws in the making of the steel — done by Cives Steel Co. — as well as the "combined effect of allowable fabrication and erection tolerances."

The initial plan for the fix was to simply loosen some bolts, and jack up the roof slightly. But that proved more complicated than first thought, given the amount of scaffolding that would have been needed, Sergi said.

So, beginning Friday, the 90-foot-long east section of the roof was to be lowered in two, roughly equal parts. Once on the ground, workers will survey the pieces and, hopefully, fix the problem. They will reassemble the pieces and do more surveying work before again disassembling them, raising them and reattaching them. Repairs on the west side of the roof will be done with the roof still in place, officials said.

Center officials said that while safety was not an imminent issue, the roof problem has to be addressed because — in worst-case scenarios — it could become one.

"It's only under the most dramatic, extreme conditions contemplated in those parameters that you deal with the question of safety," said Matt Fleury, the center's executive vice president.

The center is scheduled to open in late 2008. Sergi said the roof issue doesn't look like it will delay construction, but it could.

To see more about the science center and its magic carpet roof, go to http://ctsciencecenter.org/PR11302007.php