The self-storage industry has quickly evolved from the simple CMU walls with corrugated tin roofs of yesteryear to the modern, multi-story, climate-controlled facilities of today. While the design focus has always been on the economical security of building contents, aesthetics have become an increasingly important factor. An attractive facility not only draws more customers, it maintains a better long-term value for its owner.
One building component designers manipulate to add curb appeal is the roof. Years ago, contractors built storage projects with whatever materials were available in their area. They used roof systems such as built-up (tar and gravel), modified bitumen and synthetic membranes such as EPDM, which varied in cost, longevity and visual appeal. While these options were attractive due to the low initial cost, maintenance quickly became a fulltime job, and the industry moved in other directions. Today, the two most commonly used roof systems are the composition shingle roof and the much more popular metal roof.
Composition Shingle Roofing
Composition shingle roofs are by far the most economical way to dress up a building. Shingles soften the commercial look of a business, especially when used near residential areas. The speed of installation by an experienced crew guarantees the owner and builder faster completion, increasing profit for both.
Advances in shingle design and technology have multiplied the choices in color, texture and style, and have extended the lifespan of a typical shingle roof. Longevity, though, is also the one downfall of shingles. The average life of a shingle roof is rarely the duration for which it is rated. High wind, ice and hail result in more insurance claims on shingle roofs than any other system. In many cases, insurance companies offer policy discounts when existing roofs are retrofitted with metal, which qualifies for a higher fire rating.
Metal roofs have become the standard for modern self-storage construction. The versatility, style and longevity of metal roofing have greatly enhanced design options. In fact, the choices are so many that a designer must consider the type of metal system to use in addition to color and geometry. The four general types of metal roofing are thru-fastener, structural standing seam, snap seam or high-end hybrid.
Thru-fastener panels, such as R, PBR, M or 5V crimp, represent the most economical of the roof systems. They install quickly, are widely available and offer a wide range of colors and thicknesses. In many cases, thru-fastener systems also serve as structural support for the framing system they cover (also known as “diaphragm bracing”).
While serving roofing and a structural element, thru-fastener panels have some disadvantages. First, they must have screws to seal the holes through which they are fastened, and a cheaper fastener’s washer will break down from UV attack and start to leak. The fasteners themselves, while initially painted to match the panels, will be scratched when driven by a screw gun. If they are not immediately touched-up with the manufacturer’s recommended paint, they will eventually rust. Over time, the exposed fastener roof will also require some maintenance to ensure its water-tightness. Like shingles, panels are easy to retrofit and upgrade to a standing-seam system.
Structural standing-seam roofs, while higher in initial cost, offer a much longer lifespan with little or no maintenance. Available in thicknesses from 1.5 to 3 inches, standing seams usually incorporate a sealant or gasket in the seams to allow the panels to be used on very low slopes without the threat of water infiltration. The panel side laps are rolled, or “seamed,” together with an electric mechanical seamer that ties each roof section together into one unit.
With the onset of portable roll forming that allows panels to be custom-produced on site, panels can be run in exact lengths from ridge to eave in one piece, eliminating much of the waste encountered with factory-formed panels. These new-generation roof systems have thus eliminated the leak-prone end laps and exposed fasteners used by the older metal-building systems, creating a roof that is maintenance-free. Structural standing seams have also become the product of choice in the roofretrofit community for the many reasons listed above.
Snap-seam systems offer many of the advantages of standing seams—elevated seams, integral sealants, no exposed fasteners and portable roll forming— but they also offer the designer an alternate profile, moving away from the “industrial” look of the structural panels. These systems usually have either a snapping-type seam formed into the panels or a separate batten that snaps over the two adjacent panel legs. They offer much greater versatility in design and can be applied to more complicated geometries, with equal water-tightness.
Usually, snap-seam systems require a roof of at least a 3-on-12 slope with a solid deck and an underlayment of felt, self-adhering ice and water shield, or synthetic underlayment. Synthetic allows for longer exposure time between the under-layment and panel installation.
“Hybrid” metal roofs can vary in configuration from metal shingles to metal Spanish tiles to horizontal-running “Bermuda”-type systems. These roofs also require higher slopes with solid decking and underlayment. The wide range of products provides unlimited design possibilities.
Due to the complicated nature of the flashings related to hybrid systems, they require an additional level of expertise to accomplish proper installation. This, in turn, results in an increased cost per square foot over the standard metal roof.
The roof system is just one of many elements the storage designer/owner has at his disposal to increase the aesthetic appeal of the property. As with all facets of construction, the quality of the material is only as good as the installer.
The owner should seek a qualified design professional with a documented record of successful projects. He should also hire a contractor who is established and experienced in the industry, has knowledge of local building codes, and is factory-certified by the manufacturer of the product he is installing.
Nolan Lange is a project-management and installation trainer for A-Lert Building Systems and A-Lert Roof Systems of New Braunfels, Texas. Both are divisions of Centurion Industries Inc. The companies provide self-storage manufacturing and new and retrofit roof construction. Mr. Lange has more than 24 years of experience in the metal-building, metal-roofing and retrofit-roofing industries. For more information, call 800.210.5375; visit www.alertbuildingsystems.com or www.alertroofsystems.com.