Irregularly shaped manufacturing facility gets new sloped roof
XLT Ovens, Wichita, Kan., is a third-generation, privately held corporation that has been in business for over 60 years. XLT manufactures a wide variety of conveyor ovens and exhaust hoods used in quickservice restaurants and other institutions such as casual dining establishments and schools. XLT strives to continuously improve the design and efficiency of its ovens.
Ron Wolfe, owner of XLT Ovens, wanted his manufacturing facility located next to the Wichita airport to reflect this. He wanted to more efficiently condition the space that his employees assemble ovens in. This need for an energy upgrade and the need for a facelift to the building was the driving force for the full building retrofit.
Working closely with Greg Perry, CEO of True Steel, Ada, Okla., and Butler Manufacturing, Kansas City, Mo., Wolfe designed a retrofit that significantly increases the energy efficiency of the building and also makes a visual statement to anybody that drives by or flies over the facility. It was completed in July 2015.
Formerly Flat
The existing roof was a conventional built-up roof and a replacement built-up roof was considered. “But the visual impact or aesthetic effect wouldn’t be realized with a conventional roof,” says Rodger Russ, North American sales manager-roof systems, Butler Manufacturing.
The design took the flat conventional roof to a roof with a 2:12 slope with 12 inches of new batt insulation utilizing 202,000 square feet of Butler’s Slope Build Up light-gauge framing system (with more than 5,000 structural columns) to support Butler’s 24-gauge MR-24 roof system in Majestic Blue.
“The type of original construction made metal the obvious choice instead of hardwall construction for the walls,” Russ says. “The existing corrugated wall panels were removed and replaced with 64,000 square feet of 2-inch Butler ThermalWall Insulated Metal Panels (IMPs) with an additional 8 inches of batt insulation from Bay Insulation Systems, Green Bay, Wis., to help increase the energy efficiency of the building. The full-length IMPs extend to the roof line.”
Challenges
Since the building is irregularly shaped, establishing the height and slopes of the new roof planes took some strategic planning. The slope build-up and roof installation was to start at the east end of the building. But, the widest portion of the building occurs at approximately the center of the building, from east to west.
So, “True Steel installed a section of the slope build-up system at the center of the building to establish the baseline roof planes, then used that section of new structure as the datum point for erecting the rest of the slope build-up system,” Russ says. “The Butler slope build-up system is very forgiving and allows for adjustment, which resulted in the final roof having the flat appearance of new construction, and providing the ability to correct for dimensional inconsistencies that were present in the existing structure and its various additions.”
Once the slope build-up system was installed, the structural fasteners penetrated the existing weatherable membrane of the built-up roof, leaving the building susceptible to leaks due to weather during the construction process. True Steel eliminated this problem by installing the slope build-up system fasteners through a puddle of gun-grade sealant, which sealed the structure to the existing roof membrane, mitigating the potential for interim leaks until the new roof system was installed.
A 50 Percent Increase
The retrofit will lead to significant tax deduction upon proving up to a 50 percent increase in energy efficiency due to the retrofit. “The extra insulation added at the existing conventional roof level and the additional 8 inches of batt insulation added at the wall will likely ensure that the project increases its energy efficiency significantly to qualify for the recently passed Epact tax deductions,” Russ says.
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Sidebar: XLT Ovens, Wichita, Kan.
Owner: Ron Wolfe
General contractor: True Steel, Ada, Okla.
Insulation: Bay Insulation Systems, Green Bay, Wis., www.bayindustries.com
Metal roof retrofit system: Butler Manufacturing, Kansas City, Mo., www.butlermfg.com
