The Metal Retrofit Revolution

Delivering longevity, durability, and great aesthetics, metal roofing and cladding panels are a popular choice for today’s retrofit and adaptive reuse projects
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Metal Roofing Advantages Recap

Service life: Metal has the longest service life of any roofing material in the market today. This also means the lowest life-cycle cost of any roofing material. In fact, painted metal roofs demonstrate an average service life of 41.6 years, as compared to only 23 years for modified bitumen and built-up roofing, according to Ducker Worldwide research. Additionally, it has been demonstrated that low-slope, unpainted, 55 percent AlZn-coated metal roof systems have a service life of at least 60 years, according to a peer-reviewed study sponsored by MCA and the ZAC Association.

Strength and testing: Metal roofing undergoes one of the most rigorous test protocols in the roofing industry, the E-1592 test. This air-pressure test places the panels in a large 10-foot by 20-foot chamber and increases the static air pressure beneath the panels until failure, often explosively. The failure point is measured and a factor of safety from 1.65–2.0 is applied to establish a working load for the panel. The inherent strength of the metal roofing material and the aggressive testing used explains why metal is quickly becoming the material of choice for roofing. In fact, Monroe County, Florida, considered a “metal-only” roofing ordinance for all residential roofing.

Material weight: Steel and aluminum roofing are not only strong but also lightweight. This means the supporting structure does not have to support the significant weight of conventional roofing systems that incorporate structural decking, membranes, and frequently ballasts to hold the membrane in place. This makes the overall cost of a steel-roofed structure significantly less expensive.

Fire resistance and fire ratings: Metal roofing is a noncombustible material, which can be an important design consideration when the structure is in a fire-prone area. It can also be important in commercial and industrial applications where zoning districts are frequently divided into various fire districts with certain minimum fire resistance ratings. Stone-coated metal roof tiles are now frequently used in residential application for their documented fire performance.

Driving it Home

In summary, retrofitting with metal has long been an effective renovation strategy and is even more relevant today. Whether boosting the integrity of the building envelope and/or updating the look of an older building to compete with newer buildings on the market, metal roofing retrofits are a most valuable economic strategy.

In the final analysis, MCA’s “Retrofit Roofs Offer Design, Environmental, and Financial Benefits in New and Existing Construction” white paper states, “Metal retrofit has been a quick, cost-effective solution for problematic roof geometry, maintenance issues, and outdated appearance. In more recent years, thermal efficiency and energy savings are the hallmarks of a retrofit roof application. In addition, retrofitting has become an intricate part of building repurposing and renovation.”

 

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Originally published in Architectural Record

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