DENVER - When Maplewood, Minn.-based M.G. McGrath Inc. was hired to install the architectural sheet metal for the Denver Art Museum's $62 million expansion, company officials were excited - and a little intimidated.
"There will never be another building like it," said Michael McGrath, the company's project manager.
And for M.G. McGrath workers and U.S. Engineering, the mechanical contractor that installed the structure's ductwork, there may never be another project as unusual as the Mile High City's newest museum.
Museum officials describe the 146,000-square-foot expansion, called the Frederic C. Hamilton Building, as "geometric shards flaring out like titanium flower petals."
Those "flower petals" created several strange angles inside and outside the building, making it difficult not only to install the exterior titanium, but also the interior ductwork. The sheet metal contractors involved on the project had to approach this building in an entirely new way if they were going to help make it the modern masterpiece the architects envisioned.
With that in mind, McGrath said his company decided "to attack it with everything we had."
Rough exteriorsThe Denver Art Museum's expansion will literally connect the old and the new. When the building opens in fall 2006, a glass-paneled bridge will connect the museum's original castlelike structure with the new futuristic building that resembles a mountain of sharp glass.
The new building will also house the museum's modern and contemporary art collections, as well as its Western American, African and oceanic art collections. Traveling exhibitions will also use the structure.
According to architect Daniel Libeskind, his design for the museum tried to connect tradition with modern influences. Many of the buildings around the new expansion, including the original museum, are made from stone found in the local Denver area. The new building uses such traditional building materials, but adds a more recent one - titanium.
According to Michael McGrath, project manager for the architectural sheet metal firm, the company was provided with Libeskind's design and told to "bring to life what they had on paper."
Coming togetherGoing from a sketch-pad image to a permanent structure meant installing more than 200,000 square feet of titanium over a 150,000-square-foot building. The titanium sheets adorn the exterior walls, which come together at several sharp points.
Even though M.G. McGrath officials had worked on art museums in Delaware and Minnesota, the architect's choice of material and the geometry of the building increased this project's difficulty, McGrath said.
"It's a tougher metal to cut and work with," he said about titanium.
The company fabricated 85 percent of the metal used for the outside of the museum at its shop in Minnesota. The finished product was then shipped to the jobsite in Denver.
The titanium was installed on the exterior of the structure, which McGrath said wasn't easy: It needed to cover all four stories of the building, including the roof and a 100-foot-long prow that extended from the building and reaches across 13th Avenue, where the museum is located.
Accessing points outside the building was not easy.
"Some of the angles dive right in to each other at a single point," McGrath said. "And the roof is really steep."
In order to install the titanium, M.G. McGrath's engineers created special suspended scaffolds that would hang over the building and allow workers to reach the sharp angles. The scaffolds also had to accommodate the steep pitch of the roof in several sections.
As of late September, McGrath has completed 95 percent of its work. All that is left on the exterior of the building is landscaping work and bringing walls to a finished grade.
Winding interiorsWhile M.G. McGrath workers were installing the museum's shiny, highly visible exterior, employees from U.S. Engineering were working on the building's ductwork, piping, plumbing and HVAC systems - less noticeable to visitors but no less important.
The twists and turns of the museum's walls meant this would be no typical project for the Loveland, Colo.-based contractor. Workers would have to make 212,000 pounds of sheet metal to provide the 399 tons of cooling the building required.
U.S. Engineering's $5.7 million contract included installing all the ductwork, piping, plumbing and HVAC systems for the museum's expansion. The company's foreman on the project, Duane Thompson, described walls that start at the floor, climb 15 feet and then bend 37 degrees. While it's designed to provide a visually exciting vantage point for museum visitors, it caused visible frustration for some U.S. Engineering workers.
Thompson said that his installation technicians second-guessed their work because the ductwork did not run in traditional, straightforward patterns. The art museum has very few right angles. In fact, the only square in the entire perimeter of the building is a center atrium where the elevators are located.
"It looks odd when it is all installed," he said. "The guys would put it up and say it doesn't look right. These guys are use to running (ductwork) throughout the building."
The ductwork connects to eight separate Energy Labs HVAC units installed in the building. Four are located in the basement, two on the second floor and two in a penthouse area.
Thompson said that the large units in the penthouse are outdoor units that go through the core of the building. The air unit comes down around the elevator core and breaks off at all floors where the air-handling units are located.
The ductwork that branches out from this center core must then travel throughout the maze of twisting angles on each floor. The floor space inside the building is 146,000 square feet, while the ceiling runs at 179,000 square feet.
The company used Autodesk's AutoCAD 2000 and Architectural Desktop, CADPipe-HVAC and CADPipe from AEC Design Group to help with the complicated mechanical layout. This was important because ductwork had to be precisely placed. The company also used the 3-D-modeling programs Navis Works and Form Z to help coordinate system placement and where other trades would be working.
If it had not been for the software's 3-D model capabilities "we wouldn't have built this building," said Thompson.
Work areas were so tight, Thompson said when it came to placing the ductwork, "Nobody was allowed to go off their designated space."
As always, safety was a prime concern. Most times, the company had equipment that would help workers securely reach the points where ductwork needed to be installed.
But according to Thompson, "Ladders and lifts only do so much."
Since the walls had so many odd angles, workers had to climb them to hang ductwork. Several different scaffolds were used to accommodate the technicians working around these tight spots on the wall.
The ductwork needed to be installed in sections and tied off. Thompson said that hangers would not work. The ducts had to be attached to a stationary point. For example, straps were used to hold ductwork in place around beams. According to Thompson, with the sharp slopes and angles, the ductwork has the tendency to sag if not tied off properly.
(For reprints of this article, contact Jill DeVries at (248) 244-1726 or e-mail firstname.lastname@example.org.)