Representing the South Side

• Photo courtesy of Johns Manville Roofing Systems, Denver

The North vs. South rivalry isn't reserved for the states on either side of the U.S. Mason-Dixon Line. A battle is alive and well in Chicago between the rough Southsiders and the pansy Northsiders, stereotypically speaking, of course. As Chicago has become gentrified and expanded, the rivalry may have grown less intense (except during baseball season), but the South Side working class and North Side yuppies still have gripes with one another.

Even air travel in Chicago is represented on the North and South sides—O'Hare International Airport reigns supreme on the North Side, and Midway Airport is growing strong on the South Side, especially because of the Midway Terminal Development Program, a $722 million expansion project.

Midway Airport, known as Chicago's "other airport," opened in 1927 and was the world's busiest airport from 1945-58. Unlike O'Hare, which sits on 7,000 acres (28.3 km²) of land with 178 aircraft gates housed in four terminal buildings, Midway Airport functions with much less and often has been considered a second-class airport. But things are changing.

Originally situated on a 1-square-mile (2.6-km²) lot, the airport has expanded across Cicero Avenue—its eastern boundary line—where a new six-story parking garage opened in 1999 and the Midway Terminal Building opened in March 2001. The terminal building houses ticket counters, baggage-claim areas, and a two-level terminal roadway system separating arrivals and departures. A Federal Inspections Services Facility opened in 2002, bringing international flights back to Midway Airport after more than 40 years.

In addition, the airport's original terminal and concourse building has been reconstructed and expanded to include shops, restaurants and more concourses. Airline gate and concourse openings occurred in October 2001, but construction and renovations in this area continue and are expected to be finished in May. The expansion created 12 additional aircraft gates (Midway Airport now has 41 gates).

Roofs Inc., Lyons, Ill., was part of the Midway Airport expansion project. It installed fully adhered and mechanically attached Johns Manville Roofing Systems UltraGard® PVC membrane roof systems on the parking garage from 1997-99. The project involved two helixes, three elevator towers and other roof entry areas.

In 1999, Roofs Inc. was awarded a contract to install PVC membrane roof systems on the Midway Terminal Building; concourses; and pedestrian bridge, which expands over Cicero Avenue to connect the Midway Terminal Building to the original terminal and concourse building. This 470,000-square-foot (43663-m²) roofing project is expected to be completed in March. During the next few months, Roofs Inc. will finish setting roof perimeter curbs on the remaining portions of Concourse A, the final project phase.

Roofing work

With so much work to complete, roofing workers had to adapt to design changes. Tom Elander, Roofs Inc.'s sales engineer, says roof system designs changed from one roof section to the next because of different requirements for each section.

"Although this project will total almost 5,000 squares (46450 m²) when completed, it is more like running 20 small jobs because of the changes in the style of construction from one phase to the next," Elander explains.

Most roof areas have metal decks that required the PVC membrane to be mechanically attached. On the few concrete deck areas, the membrane had to be fully adhered. In addition, the roof systems feature a Metal-Era coping system. Because the architectural firm A. Epstein & Sons International Inc., Chicago, specified a full system warranty, Metal-Era indemnified its coping system to be covered under Johns Manville's warranty.

During the project, six crew members to eight crew members installed the insulation and other roofing materials. Two workers to four workers continue to perform sheet-metal work.

Each building—and often each roof section—had different roofing needs. For example, acoustic roof areas required a minimum 3-inch (76-mm) polyisocyanurate tapered insulation to be installed over the metal deck before the UltraGard PVC membrane was mechanically attached.

In the concourse areas, the metal deck is fluted and exposed so it can be viewed from inside the building. Wire screening and strips of fiberglass insulation were applied between the flutes on the exterior roof deck to provide appropriate acoustic properties. This area then was covered with rigid insulation board before the membrane was installed.

As part of the warranty, fascia and coping systems were installed. Expand-O-Flash™ expansion joints also were used. On the concourses, expansion joints were spaced about 300 feet (91 m) on center. The roof perimeters required an overlay of 1/2-inch (13-mm) plywood over the insulation. But because there was little or no parapet on the roof perimeter, there was not much height clearance to accommodate the depth of insulation. Therefore, insulation had to be further tapered.

Other requirements

Other considerations had to be made to meet airport requirements. Because the building is in a wide-open plain, which is typical of airports, mechanically attached membranes had to meet an FM Global 1-60 wind-uplift rating. And because of jet engine blasts, the roof systems needed to be flexible to move and vibrate.

In addition, it was important Midway Airport remain open during construction with few passenger inconveniences. To accommodate passenger needs—and keep the project on schedule—buildings were constructed while others were torn down.

"As a new section of the airport opened, an old section could be demolished to make more room for new construction," Elander explains. "Therefore, sustained roofing operations were not possible and remobilization was required."

Despite moving equipment and materials from location to location, on-site storage was not difficult—materials were stored on the roofs. But because airplanes were near work areas, all debris had to be contained. Debris was bagged during the day and placed in a Dumpster at night. No loose items could remain on a roof—if they were carried away by wind, they could damage an airplane.

In addition to meeting airport requirements, membrane color also had to be considered. On the pedestrian bridge, the owner, the city of Chicago, wanted a gray membrane (instead of a white membrane) to be used. Changes to Chicago's energy code also were a factor when deciding membrane color.

"We needed a light-colored membrane to reduce the heat island factor and comply with the Chicago energy code," says Stuart Berger, senior project architect with A. Epstein & Sons International.

Sept. 11

While those involved with the project were trying to meet different codes and standards and stay on schedule, the Sept. 11 attacks happened. Construction was halted for one month after Sept. 11 while airport and U.S. government officials considered safety and security. After Sept. 11, the security screening process changed to include fingerprints and more background information of workers. Safety films, which Midway Airport required constructions workers to watch, were updated to encourage workers to be more aware of their surroundings and report unusual activities and unauthorized people. Workers also were told armed guards were watching them.

In addition, job-site restrictions increased. Workers could only enter the airport premises through one gate, and they had to park in an off-site parking lot and take a shuttle bus to the job site. No one was allowed on-site before 6 a.m. or after 5 p.m.; those breaking this rule could be arrested.

Aspects of the roofing work process changed because all material deliveries made to the site, as well as workers entering the site with tools and equipment, were searched. Personnel delivering paperwork from Roofs Inc.'s office had to bring insurance papers and proper bills of lading and show proper identification. Vehicles used for deliveries that did not have a Midway Airport parking permit sticker were escorted to the site.

Elander notes the security measures still are enforced but they never have affected workers' performances.

The South Side rises

Despite the work delay caused by Sept. 11, work change orders, new safety regulations and the challenging logistics of working on a project for several years, Roofs Inc. has helped update Midway Airport to bring more air travelers to the South Side. In 1999, 13 million passengers came through Midway Airport. The expansion project is expected to increase the number of passengers Midway Airport serves to 17 million.

Although the airport has to address long, time-consuming security lines and other unexpected construction-related kinks, the modern airport is poised for success. And those involved with the Midway Airport expansion project seem somewhat amazed such a large job was completed so successfully.

"The challenges of the difficult site logistics and varied roof systems have been met, and we have provided the highest quality work in a difficult environment from start to finish," Elander says. "No material- or workmanship-related roof leaks have been reported on this project."

Dave Trolian, general superintendent for Chicago-based Clark-McHugh-Rausch, adds: "I've been on some of the largest projects in Chicago during the past 10 years. But I've never been on a project of this size with so few problems."

Kate Gawlik is associate editor of Professional Roofing magazine.

Project name: Midway Airport
Project location: Chicago
Project duration: 1997-2004
Roof system type: PVC with metal copings
Roofing contractor: Roofs Inc., Lyons, Ill.
Roofing manufacturers: Johns Manville Roofing Systems, Denver, and Metal-Era Inc., Waukesha, Wis.
General contractor: Clark-McHugh-Rausch, Chicago
Architect: A. Epstein & Sons International Inc., Chicago