Recognized for strong durability, low maintenance, versatile design and its long life span, metal roofs are a popular choice for contractors of both commercial and residential building projects. But not all metal roof systems are the same. To achieve the superior functionality offered by metal roofing, contractors and designers must first select the right type of metal roof for the job.
Selecting the right metal roof for the job
Dedicated to sustainability, the KVCC Food Innovation Center in Kalamazoo, Mich., used CENTRIA Versapanel insulated metal roof panels in silversmith to seamlessly integrate with the IMP building envelope with the added bonus of thermal and moisture efficiency.
Specifying the appropriate metal roofing system depends on a variety of considerations including roof slope and geometry, climate conditions of the project location, energy efficiency and design criteria. By matching these factors with the performance and design capabilities of metal roofing options available, contractors can eliminate the guesswork and provide a high-performance metal roofing system, reducing the risk of roof failure, leaks and costly damages.
Roof Geometry
Selecting the right type of geometry for your roof is crucial. One of the most basic traits is slope. The flatter the roof, the bigger potential for leaks and problems over the lifetime of the roof. Ice or snow can become stuck on a low-slope roof and back up into the seams, causing building integrity and potential structural issues. For low-slope roofs with pitches as shallow as 1/2:12, specifiers should consider structural standing seam metal roof panels. The concealed fastener roofing system protects against the elements and enables drainage of rain and snow to eliminate standing water and related leaks.
Steep-slope roofs, or those with pitches greater than 3:12, have less opportunity for ponding or ice and snow accumulation, allowing for a lighter weight metal roofing system. For these types of roofs, exposed fastener metal roof panels are often a good choice for their extreme flexibility and excellent negative wind load properties. However, roofs with steeper slopes are more visible, indicating a metal panel profile that is aesthetically pleasing, especially in residential projects.
Climate Conditions
In extreme climates where the risk is greater for significant rain, snow or ice, standing seam metal roofing systems offer superior durability and weathertightness. The interlocking seams provide a watertight seal, with a mechanically seamed option to provide even further protection. Standing seam roofs place the seam between panels above the surface of the roof, so that even torrential rainwater, piled up snow and ice stand little chance of backing into the seams.
Conversely, in hot climates where cooling expenses and energy bills are a primary consideration, insulated metal roof panels deliver high thermal R-values for energy-efficient performance. Insulated metal panels (IMPs) are an insulated, one-piece composite metal roofing panel that eliminates the need for multiple layers of roofing products. Each side is a metal skin, separated by factory installed foam, together acting as air, vapor and water barrier—as well as insulation. Adding insulated metal roofing to a building project can also help meet LEED and other green building standards. However, IMPs are not a good match for curved and very complex roof geometry.
Design Criteria
With continuous product innovations, metal roofing systems offer numerous panel profiles, configurations, thicknesses, coatings and color palettes to satisfy a variety of design criteria. Concealed fastener systems like standing seam metal roofs and insulated metal roof panels provide clean, sleek lines and a more modern aesthetic. Standing seam metal roof panels have a variety of rib profiles to choose from that create striking sight lines and also offer the option for curved panels, while insulated metal roof panels offer unique design flexibility and seamlessly integrate with insulated metal wall systems. Exposed fastener roofs, on the other hand, are extremely versatile and can be used as exterior or interior walls, roofs and soffits with ribs that run horizontally or vertically, as well as perforated options.
Topping it Off
After considering all the determining factors and narrowing down the options, specifiers can ultimately turn to the metal panel manufacturer to help ensure the final selection is the right fit for the project. No matter which type of metal roofing system you choose, ensure you’re relying on a manufacturer that will supports you throughout the project by providing detailed and current drawings, documentation, field erection details and up-to-date product specifications. The result will be a seamless installation of a high-performance metal roofing system that delivers superior aesthetics, performance, sustainability and value.
Brian Finnegan is Midwest area manager, and Ed Samek is product applications designer, at CENTRIA, Moon Township, Pa. To learn more, visit www.centria.com.
When the city of St. Petersburg, Fla., replaced the St. Pete Pier, CENTRIA Econolap 3/4-inch perforated exposed fastener roof panels in silversmith kept the project within budget while also supporting the specific design and performance requirements.
