This article Reprinted from Western Roofing magazine, January/February 2007, Volume 30, number 1

 

 

Hawaiian Reroof

An Island Airport in Need of Repair

by Tony Matter, freelance writer for the construction industry

 

 

One of the world’s most popular tourist destinations, the Hawaiian Islands offer a beautiful backdrop for a fun family vacation or a romantic honeymoon hideaway. Full of lush green rainforests, fiery lava flows, and sandy beaches nestled against a deep blue ocean, the Hawaiian landscape is unlike any other place on earth.

                  Servicing approximately 23 million travelers a year, the Honolulu International Airport, located on the island of Oahu, sets the tone for the one-of-a-kind Hawaiian experience. From incoming international flights to outgoing commuter flights that disperse visitors to the neighboring islands, the Honolulu International Airport, much like the unique Hawaiian landscape, offers travelers something different from the norm.

                  While most airports in the United States are fully enclosed and laden with concrete, much of Honolulu’s airport is open to the exterior elements. The open design of the airport allows trade winds from the Pacific Ocean to breeze through the terminal and passenger lounges, instantly offering visitors a taste of the islands. Hawaii’s largest airport truly is the beginning and the end of a fairytale-like getaway.

                  Because of the building’s unique, open design, the airport’s roof system plays an important role in keeping tourists protected from inclement weather conditions and maintaining the overall comfort that is expected when visiting the majestic islands. When the airport’s built-up roof (BUR) system and adjoining concrete walls began to fail, officials in Hawaii’s State Department of Transportation (DOT) Airports Division knew something had to be done quickly.

                  “The leaks were affecting the airport’s daily operations, often requiring us to reroute passengers around the water,” said Lyle Oda, engineer for the DOT’s Airports Division and project manager for the reroofing project. “Tourism is extremely important and we did not want to adversely effect that by inconveniencing visitors, so we decided to reroof the entire facility.”

                  Due to the large number of travelers flowing through the airport everyday, the DOT specified minimum performance requirements and went through a lengthy pre-qualification process of roofing manufacturers and contractors. A critical part of the pre-qualification process was to get roofing manufacturers to change their standard warranty and take responsibility for all materials and labor for the entire 20-year life of the roof. Certified Construction, a local contractor with years of experience, and Polyglass U.S.A., Fernley, Nevada, stepped up to the plate to give the DOT what they wanted.

                  Kevin Simpkins, president of Certified Construction, Honolulu, Hawaii, opted to reroof the 250,000 square foot airport with Polyglass’ Elastoflex® SA V and SA P three-ply, built-up roof system. Elastoflex SA V and SA P are self-adhesive roofing membranes with ADESO® technology. The membranes provide a simple, safe, and economical roof installation without compromising structural integrity and lap sealing capabilities.

                  Elastoflex membranes consist of a “true” SBS compound on the top layer and an aggressive self adhesive on the bottom layer. Elastoflex SA V membranes are reinforced with a strong fiberglass mat and Elastoflex SA P is built with high-performance reinforced polyester, both of which provide excellent dimensional stability. Elastoflex SA P also features a strong granulated surface for long-term protection, just one of the multiple surfacing solutions (MSS) that Polyglass offers with its ADESO Technology.

                  Along with being extremely durable, the Elastoflex roof system offered one advantage that was of the utmost importance to airport officials – no obnoxious odors. Eliminating the need for torching and mopping, Elastoflex membranes provide strength, weathering resistance and waterproofing performance.

                  “We held weekly meetings with Certified Construction,” said Oda. “Anyone could attend them and voice their concerns. If the project was causing any inconveniences, we would have shut it down and made Certified work during the night when occupancy was down.”

                  The old roof system was not the only source of water leakage at the airport. The concrete walls adjoining the roof were also a problem. “We considered a number of options for this project, but Elastoflex offered the best roofing solution and Polyglass was the only manufacturer that was serious about addressing the water infusion along the walls,” explained Oda.

                  To solve the problem at the adjoining walls, Certified opted to install a 60-mil Hydro-Stop PremiumCoat waterproofing system, a product that Polyglass willingly incorporated into the project’s 20-year total system warranty.

                  PremiumCoat is a UV-resistant elastomeric compound that is fully reinforced with a woven polyester fabric designed for roofing and flashing applications of all types. PremiumCoat is resistant to acid rain and air pollutants, and its installation meets VOC emissions regulations, eliminating facility downtime during application.

                  “The combination of Elastoflex and PremiumCoat provided a complete waterproofing system for the airport,” said Polyglass sales representative Mark Alexander of MBA Services Inc. in Hawaii.

                  Before Certified installed the Elastoflex membranes, they had to completely tear off the existing roof system. To minimize disruption, the project was conducted in two phases. First, Certified completed the large roof on the upper concourse and lobby, followed by a number of smaller t-shaped roofs that covered the walkways leading passengers to and from the boarding stations.

                  According to Simpkins, the most difficult and time consuming part of the project was the tear-off. “We had to be very careful not to get any debris on the tarmac or runway, not to mention the people walking below us,” he said. “We did most of the tear-off early in the morning, when the passenger and plane traffic was minimal.”

                  After the old roof system was completely torn off, Certified’s crewmembers replaced ineffective ridge vents from two of the airport’s lobbies with 40 new, 20-watt solar fans. To install the new fans, Certified had to first cut the old fans out and then build a small parapet along the center of the roofs.

                  Before Certified installed the Polyglass membranes, they also had to replace a number of skylights. The existing skylights were dome-shaped and Certified replaced them with new venting skylights, which feature 12-inch screens on the two short sides. The new skylights and solar fans will help filter hot air from inside the building to the outside, keeping travelers more comfortable.

                  After the new fans and skylights were installed, Certified adhered 4 1/2“ expanded polystyrene (EPS) insulation with crickets. The insulation helps minimize the amount of heat transferred into the building and the crickets divert any rooftop water to the drains, reducing the risk of future leakage problems.

                  When all of the insulation was laid, Certified began to install the Elastoflex SA V membrane. Certified’s 20-25 member crews installed two layers of Elastoflex SA V granulated base sheet and topped it with one layer of granulated Elastoflex SA P.

                  Both Elastoflex SA V and SA P feature Polyglass’ SealLap® and FastLap® technologies. SealLap is a technology that enhances sealing at the side seams and end laps of membranes and FastLap is a U.S. patented process through which granulated sheets are manufactured with granule-free roll ends, making tight seals at the seams and faster end laps. Together, SealLap and FastLap create a unique seaming system that allows membranes to bond instantaneously to each other.

                  To finish the roofing installation, Certified flashed all of the skylights and solar fans with Polyglass’ modified roofing bas flashing.

                  After the Polyglass products were installed, Certified applied the Hydro-Stop to the adjoining concrete walls. Applying two foundation coats and four finish coats, the Hydro-Stop PremiumCoat offered 60 mils of coverage to important transition areas around the roof. According to Simpkins, the Hydro-Stop eliminated 20,000 square feet of flashing and created a much stronger, longer-lasting waterproofing system.

                  In such a high-security area like the Honolulu Airport, one would expect a job of this size to have taken a long time. Because of the ease of installation associated with the self-adhesive Elastoflex membranes, Certified was able to complete the job in a little less than six months.

                  “During this project, Elastoflex offered a quick and easy installation,” said Simpkins. “The self-adhesive membranes were virtually foolproof.” •••