AUGUSTA

Legislative leaders will decide today whether to spend $1.2 million to overhaul the dome atop the state Capitol, an iconic and enduring structure experts say is three decades past its expected lifespan.

The dome on the State House reaches skyward atop an already imposing building that sits on high ground overlooking the Kennebec River. Looking up at the capitol from any direction, the building’s silhouette is uninterrupted by landscape or other structures, which is no mistake, according to State Archivist Dave Cheever.

But the copper that sheaths the green and rounded dome itself, which was added to the State House in 1909-10, was built to last for about 75 years — which makes replacing it nearly 30 years overdue.

David Boulter, executive director of the Legislative Council, said though it’s hard to see from the ground, the dome’s age is obvious up close. Corrosion and more than a century of wear have sprouted enough leaks that plugging them has become routine. Long-ago hailstorms pockmarked the copper, giving the historic structure the look of a huge golf ball up close.

The Legislative Council, which is made up of legislative leaders from both parties, will decide today whether to spend approximately $1.2 million to replace the sheathing next year, a sum available through the State House’s normal maintenance fund so no borrowing will be necessary, according to Boulter.

“It’s served us very well but its useful life is ending,” said Boulter. “We’ve had roofing experts take a look at it and there are significant cracks in the solder. There are holes from pinholes to the size of dimes.”

Boulter said the new dome will be exactly the same as the current one, with one major difference: It will be a completely different color until the copper oxidizes, which might take more than three decades.

“We are told that for the first 35 years, it will be brown,” said Boulter. “It will be shining like a new penny for a couple of months, then it will go to a dull brown for the next 35 or 40 years before we begin to see that green patina.”

The original State House, designed by famed architect Charles Bulfinch, who also designed the Massachusetts and U.S. Capitol buildings, was built from 1829 to 1832 at a cost of $145,000 and originally had a much lower-profile dome atop it. That dome was upgraded as part of an extensive rehab of the State House that began in 1909.

Cheever and Boulter said the dome is so iconic for Maine people that virtually no one has any interest in changing it.

“The people of Maine and our legislators are very proud of this building,” said Boulter. “It is symbolic of the state of Maine.”

Earle Shettleworth Jr., director of the Maine Historic Preservation Commission, agreed and said if there’s another building in Maine that is as recognizable as the State House, it’s probably the Blaine House right across the street, where the governor lives.

“The State House is one of the major symbols of our state,” said Shettleworth. “Its image is used in so many different ways.”

Cheever said the original architects meant for what is essentially a functional building to be beautiful.

“To say this is the building on the hill, there’s a reason why it was located here,” said Cheever. “It’s as much of a visual reference as it is a political reference as it is an administrative reference. Go to a lot of other state capitols and you will not find the setting that we have in Augusta. It was meant to elevate the spirit and elevate the soul.”

Cheever has his own personal memories of the dome. When he was a spokesman for Gov. Joseph Brennan, he used to take the governor’s son up inside the dome — a space where today access is restricted — and throw paper airplanes off it.

House Minority Leader Ken Fredette, R-Newport, said he expects no opposition to the project from members of the Legislative Council, who are scheduled to meet at 2:30 p.m.

Boulter said part of the reason he’s asking for approval now is so the state can plan for the project and take advantage of the lowest possible copper prices.

If approved, he expects construction to begin with the erection of scaffolding structure around the dome in March 2014. Replacement of the copper would take at least eight months, with little or no impact on access to the State House.

FOR MORE, see the Bangor Daily News at bangordailynews.com