Metal panel systems for low slope applications are the preferred roof covering for commercial, institutional and industrial buildings. Generally used in roof pitches ranging from ¼:12 to 3:12. The systems consists of interlocking panels commonly called standing seam roofing that run vertically along the roof surface. Varying in weight form 40-135, it is the lightest roofing product and easiest to install. The system itself places fewer demands on a building’s structural support system. Standing seam design assures adequate drainage from rain and snow, effectively eliminating ponding, leaks and related problems typically associated with BUR. Some require machine seaming during installation to ensure watertight seal. A seaming tool is simply rolled along the panels to crimp the panel seams together.
There are two types of Metal paneling typically used: Structural and non-structural (architectural).However structural is the most commonly used for its water barrier characteristics. Structural attached directly to purlins or lathe boards and does not require any sort of solid support beneath it. Because of their interlocking and active fastening systems metal roof panels are designed to meet the requirements of ASTM E1592, UL580, UL1897 and other sever wind and uplift test (winds up to 140 mph). No denting should occur on 26 gauge or thicker steel applied over a solid backing. Softer metals may be susceptible to denting. When on the roof it is recommended that you wear soft soled shoes for both traction and protection of the finish. No attempt should be made to walk on any wet roof
Maintenance: Annual freshwater rinsing to remove rain and air borne pollutants.
Suited for every climate and season. Reflects heat, resists snow and ice build up and sheds rain like an umbrella. Great strength per pound, strong but lightweight, designed to handle heavy snow and ice loads, improve structural strength – important in earthquake and high wind areas. To ensure longer life, a majority of all low slope roof materials are protected from the elements by high performance, highly durable metallic coatings. Available in a variety of material, colors, textures, and profiles.
Metal roof panels can contribute to LEED credits, awarded to buildings that use high recycled content and other green construction material. Typical low slope roof has 25% recycled content and at end of long useful life in 100% recyclable.
Ability to protect against the elements
Allow water to drain away from the roof surface
Keep building contents and occupants dry and comfortable
Long service life
Low life cycle cost
Low maintenance requirements
Resistance to wind
Not prone to degradation by organic materials, enabling these roofs to better resists the elements.
Reduce energy cost by 40% w/ heat deflecting metal coating.
Many low slope metal roof systems fail to reach their 40 year potential life expectancy due to four typical problem areas:
- End Laps
- Exposed Fasteners
- Curbs and Penetrations
- Reparability/ Replace ability
Cons: All have the potential of causing leaks.
Excessive rust and corrosion: Manufactures coat both sides of the panel with any alloy to protect against rust and corrosion. In most instances particularly in low slope construction, weathering can occur in 5 -10 yrs., potentially creating splits and holes.
Buckling: Caused by improper span application or excessive water snow or ice build up in a low area. Buckling can have adverse effects on seams creating openings and backing out of fasteners.
Fasteners backing out: causes opening in the system. There are numerous reasons for this occurrence. However it usually occurs when incorrect fastener types are used. This condition is particularly common in exposed fasteners as opposed to a system with concealed fasteners.
Ponding: contributes to surface rust. Most troublesome areas are at penetrations. Ponding at penetration is a source of concern, creating potential leak locations at vulnerable locations. The most vulnerable points occur at the topside of a down lope penetration. To eliminate this problem crickets should be considered to allow the free flow of water from the penetration to existing gutter.