Snow retention systems are generally installed on new construction projects when specified by a design professional or when a building owner wants to protect against the dangers of sliding snow and ice on a sloped metal roof. In some unfortunate cases, snow guards are installed only after property damage or injury occurs.
Adhesive/glue, mechanical fasteners, clamps, and peel and stick
Snow guards are made in various shapes and sizes to fit a wide array of roof types. The first step in the process is to determine the type of attachment method that will be used for the project. With today’s advancements in adhesives and fasteners, we now have various methods of snow retention attachment. Here’s information on the four most popular methods of attachment.
This remains the least harmful method of attachment for a metal roof and can be just as strong as other methods when properly designed and installed. This method is for attaching polycarbonate snow guards to either standing seam or mechanically fastened metal panels. The adhesive requires 672 hours of cure time above 50 F. If it dips below 50 F during this time, then the curing process goes dormant until it warms up again. A manufacturer’s spacing layout should provide superior load balancing on the roof structure.
There are several distinct advantages to adhesive attachment. This method is simple, inexpensive, requires very few tools, and can be easily done by homeowners as well as roofing professionals. Rows of guards can be spaced regardless of the location of the structural purlins. In the unlikely event the snow guard system gets overloaded and releases, there will be no water leaks or seam damage since there are no penetrations or seam crimping. Any guards that have been dislodged from the roof can be easily reattached using fresh adhesive back to the same mounting location. Professional layouts are always recommended to determine the number of rows required.
This is a good method for mechanically fastened panels. It works best when the mounting screws can be embedded into at least 2 inches of structural wood or into steel purlins. This method can be used for pad-style polycarbonate, stainless steel and aluminum guards.
VentSavers, SnoBar/ColorBar systems, and SnowBreaker products can also be applied with screws. For pad style guards, we recommend using two #14 galvanized, neoprene washered roof screws with a thick layer of UV-stabilized silicone between the guard and roof panel. When mounting bars or rails, we recommend using the Large Color Bracket for screw down panels or small Color Bracket for 2.67 corrugated roofing. Both types of brackets are mounted with #14 roof screws and include a foam gasket. Always consult with a design professional for optimum spacing layout.
Modern standing seam clamps allow for incredible attachment strength without penetrations through the metal. This allows for durable and long-lasting bar system installations without voiding any of the panel warranties.
Clamp-mounted systems can be installed year-round with no curing times required. We recommend using stainless steel or aluminum clamps with coarse-thread setscrews. Using a fine-threaded set screw in an aluminum clamp can result in “setscrew lockup.” When the setscrews lock up, the clamps have fundamentally failed, can never be serviced or repositioned and cannot be removed without panel damage. Also consider using clamps with wide throat openings to eliminate the need to panel-feed the clamps from the end of the seam.
Peel and Stick
This method is the fastest, most convenient and least detrimental to the panel but it also provides the least amount of holding strength. We only recommend this option for special or temporary circumstances. Peel-and-stick SnowBreakers can be used on any metal roof type that provides a 1.5-inch flat mounting area. Using a specially designed layout pattern, they can also be used for minimizing sliding snow and ice over isolated areas such as doorways and porches. This method is a great alternative when installing in temperatures that won’t allow for the adhesive method to properly cure.
Howie Scarboro is national sales manager at SnoBlox-SnoJax, Lemoyne, Pa. For more information, visit www.snoblox-snojax.comor call (717) 714-3011.