- The Washington Times - Thursday, December 19, 2013

The D.C. skyline is about to get another dose of scaffolding as two years of renovations begin on the Capitol dome in the spring.

The restoration, budgeted at $60 million, will remove old paint and repair more than 1,000 cracks in the cast iron dome before repainting. While there are no active leaks, there are some places in the upper dome with brown streaks and water marks, so part of the restoration will include water mitigation and weatherproofing to help protect both the iconic Apotheosis of Washington and the Frieze of American History paintings.

“We feel very confident going into this next phase that it’s the right time to do the work and we are prepared and have studied the situation enough to implement the right solution,” Kevin Hildebrand, head of architecture in the Architect of the Capitol’s office, told reporters Thursday.

Washingtonians and visitors can expect the scaffolding to start going up in the spring, though there will be evidence of some construction before then, Mr. Hildebrand said.

There will be a short time after the December holidays when visitors will not be able to see the Rotunda’s artwork, as contractors install a doughnut-shaped safety net in the rotunda above the windows to protect visitors from falling debris.

Once the net is in place, however, visitors will again be able to see the Apotheosis of Washington, a painting of George Washington ascending to the heavens surrounded by women representing liberty and victory.

While the net is being installed, a covered walkway will be built around the Rotunda to maintain a normal flow of traffic through the Capitol. During that time, artwork will be in enclosures for protection and not viewable and statues in the Rotunda will be boxed.

One important aspect of restoring a historical icon is to preserve, rather than replace, as much of the original structure as possible. While several windows around the dome are cracked, Mr. Hildebrand said they will not be replaced since they are the original windows and are part of the “historical fabric” of the building. Instead, the windows will be fixed similarly to how windshields are repaired today — — flooded with epoxy to fill the crack.

On the Capitol’s outside, scaffolding will extend from the base of the Statue of Freedom that crowns the building to the base of the dome, according to the architect’s office.

The current dome was completed in 1866 and replaced an earlier, squatter version. Despite being almost 150 years old, there is nothing inherently wrong with the cast-iron superstructure. In fact, when tested, the cast iron was found to be still strong even by modern standards, Mr. Hildebrand said.

There’s little room for error when working on such an important structure, but Mr. Hildebrand said he is “confident in our technique” since everything to be used in the restoration has been tested before on other pieces of the dome. The stitching technique of filling cracks in the cast iron with small metal pins, for example, was tried out first successfully on a dome skirt restoration project that wrapped up last year.