Durability, Thermal Stress and Snow Protection
This is the fourth in an occasional series of posts about metal roofing, which has become increasingly popular in recent years because of its durability and ability to add to the aesthetic appeal of virtually any building – residential or commercial. Although primarily focused on residential applications, our post content is relevant for commercial installations as well. Follow these links to read the previous posts:
- Overview of Standing Seam & Barn Metal
- Attachment & Fasteners
- Finishing: Standing Seam vs. Ribbed/Barn Metal
Durability & Thermal Stress
Standing seam roofs made from 24-gauge metal are less likely to be affected by thermal expansion and contraction than lightweight barn metal, reducing long-term stress on fasteners. In addition, these roofs will withstand hail better, won’t bend as easily if walked on, and will maintain straighter lines – it’s a much more durable and attractive installation.
Thinner, barn metal roofing panels (26 or 28-guage) are more susceptible to damage from hail and other rooftop activity, such as foot traffic. In addition, this thinner metal is subject to a greater degree of thermal expansion and contraction than thicker standing seam metal and is more susceptible to “oil canning” – a visible unevenness on installed panels.
Ribs (also known as striations) in barn metal panels can help diminish oil canning and other visual defects to a degree, but ongoing thermal movement puts stress on fasteners. This can eventually cause them to fail and compromise the installation, which leads to rust and interior water damage.
Snow and Ice Protection
In northern climates, cold weather brings frozen precipitation, which has implications for metal roofing. Snow and ice do not slide on a shingle roof but do on a metal roof, which can damage gutters and create a hazard for pedestrians and vehicles.
To prevent or limit the sliding snow, metal roofs need snow and ice guards. Standing seam roofs use bar-type guards, which are attached to the metal seam with clamps. In addition to preserving the watertight integrity of the roof because they’re non-penetrating, these snow guards are permanent and can enhance the look of the roof.
On ribbed, barn metal roofs, which don’t have standing seams that clamps can utilize, snow guards must be attached with an adhesive that can deteriorate over time; or screws, creating additional roof penetration problems.
Royalty Roofing has a proven history of installing standing seam metal roofing systems for homeowners and commercial facilities. We would welcome the opportunity to discuss your needs and our capabilities. Please give us a call at 800-303-8392 or submit the contact form on this page.