When the owners of the Cranberry Industrial Park in Cranberry, Pa., had a roofing problem that previous roofing contractors had not been able to solve, they turned to Paff Contractors LLC, Pittsburgh, for a new solution.
The original 62,000-square-foot (5,760-m2) standing-seam roof featured 56-foot- (17-m-) long panels that started to leak over time due to expansion and contraction from snow, rainfall and heat, causing the screws to pull apart from the metal sheets. Additionally, when ice formed in the gutters, it prevented water from properly draining off the roof during a thaw, resulting in a drainage backup and forcing moisture to enter through the panel’s roof seams.
Paff Contractors recommended the DuroShield custom-fabricated, reinforced PVC roof system, manufactured by DuroLast Roofing Inc. in Saginaw, Mich. Paff Contractors installed 59,903square feet
(5,565 m2) of Duro-Shield white membrane and 2,160 square feet (201 m2) of parapet material, which are both Energy Star rated with a solar reflectance of 86 percent.
“[The owners] were originally looking at spray coating companies but went with us because we were able to provide a better solution,” said Tom Paff of Paff Contractors. “The flute-filler, Durofold underlayment and Duro-Last roofing products gave them the solution they were looking for.”
The Duro-Shield roof system was installed over the existing metal deck, requiring no tear-off of the old roof. Thirty-eight skylights were removed and closed off with corrugated steel. Insulation was then cut, and 59,350 square feet (5,514 m2) of 2- inch (51-mm) polystyrene flute fillers were installed. Another 3/8-inch (10-mm) Duro-Fold underlayment was then added to ensure a fl at surface. The prefabricated membrane was mechanically fastened to the deck with
#15 drill point screws, while prefabricated fl ashing for stacks and other penetrations were heat-welded on-site to assure a monolithic leak-proof roof system.
To prevent water and ice buildup, 900 feet (274 m) of 1 3/4-inch
(44-mm) termination bar was installed along the right and left parapet wall and rear gutter line. To alleviate the problem the old gutter system had of allowing water to infiltrate behind the wall of the building, a custom-made roof apron gutter was installed. In the middle of the roof, 600 feet (183 m) of walk pads were installed for accessibility to the HVAC units.
“We were much more competitively priced than some of the other roofing companies,” Paff said. “We could put down 2,500-square-foot
[232-m2] sheets at a time, helping to reduce labor costs and allowing us to install the installation more efficiently.”
Furthermore, Paff Contractors was able to reroof the building without any distractions to the daily operations of the office building and the 13 tenants. Using a fi ve-man crew, the project was completed in two and a half weeks. Additionally, approximately 70 percent of the waste materials from the project was removed for recycling.
