News

Typical Life Span of Insulated Metal Wall Panels

One of the big attractions of insulated metal wall panels and roofing systems is that their typical life span can double some of the competing material.

Insulated metal panels (IMPs) can deliver a much longer service life than shingles, single-play, and built up roofing.

“An MCA study reports that certain metal roof systems can have a service life of at least 60 years,” says the Metal Construction Association (MCA). “Most noteworthy, the study has been verified by the third-party Athena Sustainable Materials Institute (ASMI), a nonprofit research collaborative that assesses the life cycle of various products within the construction sector to deliver accurate, essential information about the footprint of projects or materials.

The durability of metal wall panels and roofing systems make them an excellent return on investment compared to other materials, with longer life spans according to the National Association of Home Builders (NAHB) than wood shake roofs (approximately 30 years), fiber cement shingles (25 years), and asphalt shingle/composition roofs (20 years).

“Metal roofing and wall systems are increasingly the choice of facility managers for both new structures and retrofits,” says FacilitiesNet.com.

Your Metal Wall Panels May Outlast Your Building

The ASMI report found that your metal wall panels, and roofing systems may outlive the service life of your typical building.

Based upon the field inspections of 14 low-slope, unpainted 55 percent Al-ZN alloy-coated steel standing seam roofs with up to 35 years of service across the United States, the report concluded that:

  • The expected service life of a similar roof constructed today in a wide range of environments using best practices can be expected to be in excess of 60 years, a value that equals the assumed building service life as described in LEED.

  • Sealant service life is conservatively projected at 6o years.

The report conclusions found that the 60-year life span could be the tip of the iceberg when it comes to coating life span: “55 percent AL-ZN alloy-coated steel panels have weathered uniformly with corrosion rates that conservatively project flat panel services lives ranging from 60 to 375 years for an AZ55 coating, depending on the local precipitation pH. In all but the wore case, coating life is 79 years or more.”

U.S. Military Bases Opting for Metal Because of Durability

The MCA Continuing Education Center article “Put the Pedal to the Metal” said that the U.S. Department of Defense’s new construction and reroofing for U.S. military bases features some 290 million square feet of metal roofing.

This is more than half of the new construction and reroofing done by the U.S. military, keeping it in line with an estimate by MCA that about half of all 1- and 2-story business buildings are now built using metal building systems.

“As a result, it’s safe to assume that a majority of low-rise government buildings being constructed today are made of metal,” says Dan Walker, professional engineer and assistant general manager of the Cleveland-based Metal Building Manufacturers Association.

Walker says that metal systems are becoming very common for use as fire stations, police stations and local government offices. Metal structures also serve as recycling and service centers and other municipal facilities.

A typical example of a government project utilizing metal wall and roofing systems, according to the MCA, is the Goodfellow Air Force Base in San Angelo, Texas, which received a new metal roof integrated with energy-efficient technologies as part of the DOD’s effort to produce or procure building energy from renewable sources, and reduce overall energy use.

IMPs Offer Long Life and Low Maintenance

The MCA educational material says that insulated metal panels are “almost impervious to pests, able to withstand extreme weather, and noncombustible, metal roofs are unmatched in durability and longevity. Many manufacturers’ warranty their metal roofs for decades, and the expected lifetime of a metal roof can be significantly longer.”

Gloria D. Lee, principal of Swift Lee Office Architects in Pasadena, California told MCA that “metal walls and roof systems contribute to a high-performing building envelope in so many ways. When we’re discussing wall-panel systems, there’s the high insulation value, no need for thermal bridging of wall framing, low maintenance, long life, and resistance to moisture and mold. With regard to roof systems, there’s the high SRI, low maintenance and long life, and the fact that it’s PVC free and provides a clean surface for rainwater harvesting. For both walls and roof systems, the recycled steel content is a clear plus.”

A big bonus for building owners is that metal wall and roof systems require very low maintenance compared to other materials.

“Property managers and owners report that their metal roofs require little or no regular maintenance. Metal-roof owners spent a mere 3.5 percent in maintenance costs, as compared to 19 percent for single-ply roofs and 28.5 percent for asphalt, according to a BOMA International white paper, “Metal Roofs and Walls, Promoting the Future of ‘Green’ and Sustaining the Environment,” “reported the MCA.

Long Life Span Make IMPs a Sustainable Solution

Sustainability and green initiatives are important in today’ construction and building environment and IMPs longevity, recyclability, and compatibility with retrofits and solar technology make them a sustainable solution.

Lee told MCA that the most noteworthy attributes of metal walls and roofing retrofits: long life, low maintenance, reduced probability of water intrusion, recycled steel content, high solar reflective index (SRI), light weight, and metal roofs’ compatibility with clip-on photovoltaics (PV) or thin-film peel-and-stick PV.

Builders on commercial projects are finding that they can not only improve sustainability with the use of IMPs, but these alternative materials to conventional concrete wall systems can ultimately save costs as well.

“IMPs support many sustainable design criteria and so they are often selected on projects that are either pursuing green building certifications or where the owners want the buildings designed to be green conscious,” says the MCA.

Built to Last: IMP Coating Technology Increases Lifespan

IMPs manufactured from steel offer a very durable surface to apply paint or coating that will protect the panels from the elements.

“The finishes are applied during the manufacturing process in a controlled environment to help ensure even greater protection and longevity,” says the MCA.

Green Span Profiles, for example, offers Kynar 500 or Hylar 5000 coating systems with a warranty that says when used in exterior applications:

  • For a period of 40 years from the date of shipment, the coating system will not crack, check or peel (lose adhesion)
  • Green Span Profiles also offers a siliconized polyester coating system that when used in exterior applications:
  • For a period of 30 years from the date of shipment, the coating system will not crack, check or peel (lose adhesion)

Judging from the ASMI research, it would not be surprising if building owners ultimately experienced longevity from their metal wall panels and roofing systems beyond the warranty periods.

Topics: Insulated Metal Panels, Green Span, Construction