Reflectivity Plus Longevity

Goodrich Aviation Technical Services Inc., Everett, WA, has a 635,000-squarefoot hangar that houses 200,000 square feet of office space, warehouse area, and various shop operations. Called Hangar III, the building was completed in November 1993 with a black emulsion surfaced, four-ply built-up roof over½-inch fesco, and 3-inch isocyanurate foam insulation over metal deck. When Goodrich management realized they were getting a large number of complaints about interior heat and also noticed several leaks in the roof, they knew it was time to re-evaluate the hangar roof’s performance and decide how to proceed.Roof restoration was considered for several reasons. First and foremost was the incredible heat gain inside the building, which was caused by the solar absorptivity of the black emulsion roof surfacing. Secondarily, there were numerous nuisance leaks, mostly along expansion joints and roof area perimeters.Goodrich originally considered resurfacing the roof with an aluminum coating, but since the roof was in moderately good condition, Tim Hollar, Metal Roof Technologies Inc., suggested using a restoration product. He recommended installing test patches of two different grades of aluminum coating, and also to test TOPCOAT® MB and TOPCOAT® SURFACE SEAL SB. Both TOPCOAT products are a brilliant white when installed, offer 85-percent-plus reflectivity, and meet or exceed all EnergyStar® roof product requirements.Once all test patches were set, measuring the surface temperatures on a 68-degrees F. day with hazy sunshine confirmed that the black roof was very hot, the two grades of aluminum were warm and warmer, and the TOPCOAT material, supplied by Wayne, NJ-based GAF Materials Corp., was “cool as a cucumber.”Since the TOPCOAT installation, complaints from the upholstery shop about interior heat have ceased and the roof no longer leaks. Additionally, the product’s enhanced UV protection and dramatically reduced roof membrane temperatures will significantly extend the longevity of the existing roof system.