When building owners were asked what matters most in roofing materials, they ranked service life and lifecycle cost first and second. Initial cost ranked ninth out of 10.
This finding from a study by Ducker Research Company on the lifecycle costs of low-slope roofing cut across the three major roofing material categories: metal, asphalt and single-ply.[i] The message is clear: building owners are looking for a roofing system that lasts for many years and saves money over the long term.
Experience demonstrates that a building’s roof system can account for 10% of total construction costs but up to 60% of total lifecycle maintenance costs. Of course, the lifecycle costs of roofing go beyond material and maintenance. Broadly speaking, the choice of a roofing system impacts energy consumption in categories including heating and cooling, lighting, feasibility of roof-mounted renewable energy, potential for government tax incentives and utility rebates, as well as the market value of the building itself.
Research and product testing, combined with in-the-field experience spanning four decades, make a strong case for standing-seam metal roof systems. These roof systems offer durability, low maintenance cost, and adaptability to current trends driving energy efficiency and sustainability in the commercial building sector.
1) Save on Lifecycle Costs A Ducker Research Company study drew from case studies involving 36 roofing systems across the United States. The study covered office, retail, institutional, and warehouse/industrial buildings to include 12 metal, 12 asphalt and 12 single-ply roofs, averaging 92,000 square feet.
An earlier study that analyzed overall life expectancy found that metal roofs had an expected service life of 40 years vs. 23 years for asphalt and 20 for single-ply. The more recent study placed the lifecycle cost of metal roofs at 30 cents per square foot per year, compared with 37 cents for asphalt and 57 cents for single-ply based on expected service life. Owners reported spending 3.5% of total installed costs on maintenance for metal roofs vs. 28.5% for asphalt and 19% for single-ply over the expected service life.
Inherent qualities of metal roofs help account for these differences. Today’s standing-seam metal roof systems are proven to deliver weathertight performance for 40 years or more. The roof acts as a monolithic steel surface covering the entire building.
Attributes of these roofs can include:
- Roof clips that securely hold the roof panels to the structural members, with the flexibility for the panels to move with expansion and contraction caused by daily and seasonal temperature changes
- Weathertight sealing, with 180 degrees of the roof panel seam field-rolled to complete a 360-degree Pittsburgh double-lock seam, also impregnated with sealant
- Factory punching to ensure proper alignment of the roof panels, paired with heavy-duty fasteners
- Splices staggered to prevent exposed seams and leak points that are located directly over supporting steel to withstand foot traffic and snow loads
- Steel-rod bracing that will not stretch or sag, allowing the roof to retain its original strength and tightness
- Roof curbs and openings engineered at the factory and fasteners concealed inside the curbs to eliminate leaks
These metal roofs in many cases can be applied directly over aging asphalt, single-ply, or metal roofs to restore weathertight conditions and provide long-term building protection.