In today’s public conversations about how to properly reduce the country’s growing infrastructure deficiencies, roads, bridges, dams, and water-treatment and sewage plants dominate the conversations. Less discussed, but equally important, infrastructure elements are the roofs on billions of square feet of public buildings throughout the U.S. Public buildings consist of K-12 schools; universities; community colleges; prisons; along with other federal-, state- and locally funded buildings.
According to current studies performed in North Carolina’s public schools (K-12) and North Carolina state-owned facilities markets, the roof is equal to the HVAC component as the largest unfunded need in building repair and/or replacement costs. These infrastructure evaluation summaries are mirrored throughout the U.S. for public buildings. Per North Carolina and most states’ general statutes, the roof is required to be designed, specified and installed in the most cost-efficient manner during the life of the structure. According to the Washington, D.C.-based U.S. Green Building Council LEED v4 for building design and construction, building components should last for 60 years or more. Some say this is the definition of sustainability.
When considering a roof for a public building, a standing-seam metal roof should be considered as a possible choice.
Strength and Durability
In 1988, representatives of Brunswick County School District in North Carolina decided to install sloped metal roofs over failing existing roofs. Three high schools, totaling more than 350,000 square feet, were covered. In the mid 1990s, two of the district’s elementary schools received partial retrofit metal roofs. Starting in 2012, district representatives initiated a program to convert three middle schools and one elementary school from flat roofs to retrofit metal roofs. Added together, these roofs total more than 850,000 square feet.
In September 2018, Hurricane Florence dumped more than 40 inches of rain and initiated hurricane and gale-force winds during a four-day period in Brunswick County. All the retrofitted metal roofs withstood these extreme weather conditions without panel replacement or any major repairs. See Photo 3.
It must be noted that public metal roofs, as well as all other roof systems, must be designed by a licensed architect or engineer in the state where they are to be in- stalled and installed properly by a qualified contractor. When these requirements are met, and the design professional monitors the actual construction of the roof, a metal roof can be expected to resist the forces of extreme weather, such as Hurricane Florence in North Carolina. Of course, not properly designed or installed, any roof will fail during such extreme events. Because hurricane-like conditions are becoming more prevalent, new wind-design calculations are included in the current International Building Code (IBC), as well as local code supplements.
Convert a Flat Roof to Metal
Any low-slope roof can be converted to metal, like the Brunswick County School District’s roofs. In the early 1980s, the roofing industry developed a method for adding slope to an existing flat roof with a light-gauge framing system. This allowed existing buildings’ flat roofs to be retrofitted with a new sloped metal roof.
One of the first large industrial applications of this metal retrofit method is shown in Photo 4. In 1981, this Troy, Ohio, industrial facility’s representatives converted a 102,000-square-foot plant and attached office to a 1/4-in-12 sloped metal roof using light-gauge framing and additional insulation. Photo 2 shows the same roof in 2001, 20 years later. At the writing of this article, the roof still is functioning and has needed no replacement or repair after 37 years of service.
PHOTOS: Metal Roof Consultants Inc.
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