Stewards of the iconic buildings and grounds of Capitol Hill since 1793.

Featured

Black and white portrait of Constantino Brumidi holding an easel and paintbrushes.
Constantino Brumidi (1805–1880) is best known for the murals he painted in the...

Featured

View of the U.S. Capitol Building from above at dusk
In order to ensure the safety of visitors and staff and to preserve the...

Featured

Painted portrait of Dr. William Thornton
 The Architect of the Capitol (AOC) is the builder and steward of America’s...

Featured

Anne Frank Tree and marker planted in the ground in front of the Capitol
Anne Frank Tree on Capitol Grounds

What's New

Dome Keepers

AOC employees patch the roof of the U.S. Capitol
Saturday, March 13, 2010

 

The iconic “Walter dome” atop the Capitol is recognized around the world as a symbol of American strength and freedom. During its construction from 1855 to 1866, perhaps the greatest threat to the dome was the outbreak of the Civil War. To protect the capital city, a garrison of Union soldiers was stationed within the Capitol.
 
Since that time nearly 150 years ago, while the Union was restored, multiple forces have been unrelenting in their attack on the Capitol—time, weather, and nature.
 
Today, a small unit of men has the task of protecting and preserving this most important American icon. Led by Bryan Glotfelty and headquartered beneath the Capitol like “Men in Black” accessible only by a secure elevator, the men of the Capitol Sheet Metal Shop go to battle monthly with the forces of wind, water, and wildlife.
 
On a cold winter morning—the wind blowing a steady 20 miles per hour and a wind chill in the teens—Larry Neal and Mark Focht of the Capitol Sheet Metal Shop climb through a locked door out into an open space within the dome skirt (the area around the foot of the dome). This is their base camp next to the original sandstone walls built in 1824 by Charles Bulfinch in support of the first dome of the Capitol.
 
While Larry is a bit more understated, Mark is not shy about the pride he has in his shop. He says wryly, “We do it all. If it wasn’t for our shop none of the other shops could function. Everyone needs something metal to do their job.”
 
Setting out from their small roof encampment to begin their inspection of the Capitol roof and dome, personal protective equipment and tools in hand, they begin the climb up to the top of the dome via the 365 stairs installed during the construction in the late 1850’s.
 
They make their first stop about 85 feet above the floor of the rotunda at the peristyle level. Here that small exterior ledge is accessible only with proper safety equipment. This level has many downspouts that carry water runoff down through the skirt. Each downspout must be inspected and any debris must be vacuumed out.
 
“Copper’s worst enemy is dirt,” says Mark.
 
Heading up another 30 feet they reach the boiler plate level with a more accessible ledge that has a balustrade (railing around the edge). Along the interior base of the balustrade is a two- inch gap for drainage covered by wire mesh that traps dirt, seeds, and other wildlife deposits. To ensure proper drainage the balustrade, running the entire circumference of the dome, must be cleaned by hand, broom, or vacuum.
 
Once the walk around the balustrade has been completed, Larry and Mark head up to the balcony 210 feet above the Capitol’s East front plaza. Here, wooden floor boards must be unscrewed and removed and then all the debris must be removed for proper drainage. Next, they head into the Tholos and pedestal of the Freedom statue completing the top-to-bottom dome inspection.
 
Heading back down to the roof of the Capitol, another key aspect of the inspections is the examination and repair, where needed, of nearly 100,000 small copper panels covering the roof that remain true to the original construction. In order to make any repairs the Sheet Metal Shop team carries fire pots that resemble a portable blacksmith’s shop, along with a 20-pound propane tank and trim irons in order to solder the plates together ensuring a waterproof seem across the roof.
 
Despite this monthly fight, the dome and skirt require additional support. Like a patient with high cholesterol, the work cleaning the pipes by the doctors in the Sheet Metal Shop keeps the dome alive, but more significant surgery is needed for the long term health of the dome.
 
This is where architect Kevin Hildebrand and project manager Eugene Poole with the Project Planning and Management Division come in. These specialists are leading the effort to overhaul the dome in the coming years and ensure its health for generations to come.
 
“It’s a unique beast. There is nothing like it,” says Hildebrand. “It is the perfect marriage of material and technique of the time.” In fact, the Capitol dome is the largest cast iron dome in the world.
 
Beyond the iconic nature, remarkable ingenuity of construction, and history—the dome ultimately sits atop a working office space and is visited by millions annually from around the world. The ability to balance these needs with the work essential to the health of the dome is the challenge the AOC is tackling.
 
A major renovation within the interior space was completed in the early 2000’s when 80,000 pounds of lead based paint were removed and recycled, and surfaces of the interstitial space were painted with an epoxy paint system. The last significant exterior renovation of the dome was conducted in 1959.
 
The next phase of the dome restoration project is to repaint the exterior to hold the dome over until a more complete overhaul can commence potentially following the inauguration in January 2013 and lasting up to three years.
 
During this project lead paint will be abated from the exterior of the dome and the interior surfaces of the Rotunda, along with the repair of over 1,300 known and anticipated defects in the ironwork. This will be followed by a resealing and repainting of the ironwork with an epoxy and urethane paint system. Additional work will include the installation of new fall protection systems, a new mechanical ventilation system within the interstitial space, and replacement of the existing lighting systems within the Rotunda and interstitial space with energy efficient lighting and new lighting along the dome tour route.
 
Meanwhile, the dome will continue to be protected by Larry, Mark, and others in the Sheet Metal Shop in their monthly battle to protect this American marvel of engineering and global symbol of democracy.
 
—Matt Guilfoyle
Foundations & Perspectives, Spring 2010