Georgetown University was built in 1789 in Washington, D.C., and is the U.S.' oldest Catholic university. The main campus's Healy Hall was built between 1877-79 and is named for Patrick Healy, the first black president of a major American university.
Healy Hall, a Flemish Romanesque building, was added to the D.C. Inventory of Historic Sites in 1964 and the National Register of Historic Places in 1971 and was named a National Historic Landmark in 1987. Georgetown University's current president's office is located on Healy Hall's second floor.
When Healy Hall needed its original slate roof system replaced because of leaks, university officials asked Wagner Roofing, Hyattsville, Md., to perform the work.
"Wagner Roofing has been doing work for Georgetown University for years," says Lee Simon, Wagner Roofing's estimator and project manager. "The base bid was to replace all the slate on the rear elevation on both sides of the building's clock tower."
Wagner Roofing began work on Healy Hall in July 2007.
"For this project, scheduling was important because the job had to be done during the school's summer vacation," Simon says. "The project was supposed to start in June. However, because of some contract delays, we did not start until the end of July."
Wagner Roofing began by tearing off the building's existing roof system.
"The original building is masonry and wood-framed," Simon says. "The roof deck consisted of lath strip set in poured-in-place gypsum over wood sheathing. The lath strip was set 6 1/2 inches on center to match the slate's nailing pattern, and 10- by 16-inch slate was nailed to the lath strip."
Simon says the most difficult aspect of the tear-off was the deteriorated roof deck.
"In areas where the gypsum was cracked or missing, we replaced it with mortar," he says. "In large areas where all the gypsum and the lath strips were deteriorated, we used two layers of 3?4-inch-thick fire-retardant plywood to match the thickness of the surrounding deck. In several areas, the old roof leaked severely enough that the gypsum, lath strip, roof sheathing and structural rafters were all deteriorated and had to be replaced."
After tearing off the existing roof system, Wagner Roofing installed new 16-ounce lead-coated copper flashing, hip and ridge caps and shop-fabricated gutters. The company also repaired existing dormers.
Wagner Roofing installed Greenstone Slate Co.'s CUPA unfading black slate from Spain for the bulk of the project, and the existing red pattern on the roof was replicated with 10- by 16-inch Vermont unfading red slate.
"Matching the historic slate patterns and profiles of the original roof was a challenge," Simon says.
Working with obstacles
Trying to match the historic slate was not the only challenge Wagner Roofing faced during this project.
Even though work was being performed during summer vacation, summer classes still were being conducted at Georgetown University. According to Simon, one of the biggest challenges Wagner Roofing faced was setting up five-story-high scaffolding and working while the building was in use.
"We erected scaffolding along the entire roof's eave with safety netting at the safety rails, below the walk platform and at ground level," he says. "Our scaffolding sat in the building's courtyard and above the main courtyard entrance, so even during summer vacation it was a busy area."
A pedestrian tunnel was set up to allow pedestrians access to the building's rear door, as well.
"We fenced off the scaffolding entrance and installed plywood at the bottom of our ladder to prevent students from gaining access at night," Simon says.
Wagner Roofing also had some issues with building access.
"There were two problems with access," Simon says. "The first was the building's location. The rear of the building sat a story below grade, so the bottom of the scaffolding was about 10 feet below street level where the materials were being delivered. Instead of bringing the material up from the street and lowering it 10 feet to the base of the scaffolding before hoisting it up, we built a 10-foot-tall scaffolding ramp from the base of the scaffolding to street level.
"The second problem was a combination of location and schedule," Simon says. "The street was about 200 yards from the building, and to get from the street to the building we had to cross the school's courtyard. Because summer classes started early, we moved all material and debris in the mornings using a forklift to run between the scaffolding ramp and street."
Also, because work started in late July, Wagner Roofing had to increase its manpower and work the slate crews and sheet metal crews concurrently.
"There was a four- to six-man slate crew and a three- to four-man sheet metal crew," Simon says. "When both crews were working at the same time—which was during about half of the job—we had as many as 10 men sharing the limited scaffolding space."
A fun challenge
Despite numerous challenges, Wagner Roofing completed the project in October 2007. And it proved to be satisfying.
"The history of the building with the exacting specifications presented a fun challenge," says Kevin Morgan, Wagner Roofing's project superintendent.
Simon agrees: "Balancing quality, speed and safety—especially on historic buildings—is always challenging, but it made the job that much more unique and rewarding."
Ashley St. John is Professional Roofing's associate editor.
Project name: Georgetown University's Healy Hall
Project location: Washington, D.C.
Project duration: July 2007-October 2007
Roof system type: Slate
Roofing contractor: Wagner Roofing, Hyattsville, Md.
Roofing manufacturer: Greenstone Slate Co., Poultny, Vt.