by Russell Boniface
Associate Editor

How do you . . . re-sheathe a structure with a stronger and more sustainable exterior skin?

Summary: Construction began this month on the skin replacement of the iconic Louisiana Superdome in New Orleans. Baton Rouge-based Trahan Architects is the lead architect for the restoration and upgrading of the stadium, damaged by Hurricane Katrina in August 2005. Trahan Architects has overseen all phases of the $200 million of repairs and enhancements. Trahan Architects’ sustainable skin design is the final phase of the restoration project. Construction is scheduled to be complete in May 2010.

Trahan Architects was the lead architect and managing partner of the team that restored the Superdome after Hurricane Katrina, allowing the famous venue to reopen in 2006. The first phase of repair included the replacement of the 10-acre roof and the removal of 4,000 tons of debris, 800,000 square feet of drywall, and 600,000 square feet of ceiling tile. The second phase of work included a functional, aesthetic, and code upgrade of luxury suites and concourses. This included ADA accessible design upgrades wherever possible. In this final, two-part phase, Trahan’s design calls for an exterior skin replacement using anodized aluminum. The new skin will replace approximately 400,000 square feet of exterior aluminum panels damaged by Hurricane Katrina.

The first part of the $18 million adonized aluminum skin replacement project is about to be completed. The new skin for part one is located at the four concourse corners and features glazing and louvers. The next part of the skin replacement will cover the rest of the exterior of the building and be completed in 12-14 months.

Aluminum skin acts as a rainscreen
The original aluminum exterior panels of the Louisiana Superdome were riveted together, making it impractical to replace damaged panels because removing one panel meant removing every panel above it. A new exterior paneling system was needed.

The new skin will be stronger and made of light-bronze anodized aluminum panels, each 12 inches by 25 feet. The new panels have the same shape as the original skin panels, however they will be affixed without rivets, allowing for individual panel replacement. At the four concourse corners, the panels have windows covered by louvers. This provides both views into and out of renovated club lounges and sun shading to reduce cooling costs.

The new skin, unlike the original, will have a foam waterproofing membrane backing to allow the skin to act as a rainscreen, equalizing wind pressure at panel junctures and negating rain infiltration. “The original aluminum skin acted as the waterproofing for the exterior skin and the dome,” says Trey Trahan, FAIA, principal of Trahan Architects. The new system solved two problems, he said. If part of the old, riveted membrane roof blew off the dome, many of the panels along that vertical face were damaged. With the new rainscreen system, if an individual panel is damaged by the inevitable next hurricane, it acts in system as a single piece that is readily replaced later.

The new covering also opens up the corners on the lower concourse, allowing the Superdome to connect to the urban surroundings. Trahan refers to the original Superdome as an introverted vessel within an urban context. “When the Superdome was built in 1975, there was very little around it,” he says. “Now there are office buildings, restaurants, and retail. To make a contextual connection, we removed the opaque panels and inserted a glazing system on the corners, with 1x2-inch adonized louvers. This also deals with sun issues relating to specific orientations. The new skin still maintains the monolithic appearance of the dome.”

More than skin deep
The anodized aluminum Trahan Architects specified is thicker than the original, providing better protection. The firm also liked the material’s reflective properties. Says Trahan: “It mimics nature by reflecting the light. The dome also appears richer—not the dead appearance of painted steel.”

Testing shows that the foam waterproofing behind the new membrane provides an upgrade in the R value of the system, from 2-4 to 16-18. The system was subjected as well to a rigorous wind and rain testing to achieve current building codes and energy.

Trahan hopes the Superdome’s new appearance will be well received. “It’s such an iconic building and occupies an important position,” he says. “We are really proud of how it’s turning out.”