Like no two snowflakes are alike, no two snow retention systems are identical, except in carrying out their objective of preventing dangerous amounts of snow and ice from sliding off the metal roof.
All sorts of smart people have come up with efficient methods to hold snow on a roof and there are plenty of opinions as to what works best. From our experience, snow retention systems are like metal roofing — it all works in the correct application if installed properly.
Then, like anything, it comes down to aesthetics and pricing for the customer.
A handful of manufacturers/suppliers were willing to help us out with a few questions concerning snow retention. Hopefully, there’s some useful information here for you and your business.
Q. What is one thing contractors generally do not understand about the installation of your snow retention products?
Brian Stearns, Alpine Snow Guards: Alpine has tested and continues to test new products for ultimate load values that can then be translated into allowable load values. Using this data we can assist contractors in determining the proper use of our products on any given roof. All too often contractors guess at snow guard system design based upon reference lines on a set of drawings. It causes contractors a lot of grief and often loss of money if they don’t cross reference project specifications to see if the architect is calling for the snow guard manufacturers recommended layout. Reference lines place don a drawing to represent where snow guards are needed don’t always match with the quantities the snow guard manufacturer will recommend.
Joe Salvatore, Berger Building Products: Sometimes contractors do not realize adhesive caulks for polycarbonate and cast aluminum snow guards perform differently. Berger has tested different adhesives and only recommends Surebond Everseal SB-190 for use with Berger snow guards. SB-190 has a 2,000-pound tensile strength for superior performance for snow retention purposes. When using SB-190, it is important to properly plan the installation, as there is a 28-day period before the product is fully cured.
Rob Haddock, S-5! Solutions:
They must be individually designed for each application — which is easily done using our online calculator.
Jason Nagaki, Snobar: The one thing contractors, architects and owners don’t understand is that most of the time one row of snow guards is an under-designed system that could potentially cause major damage to their building or worse yet harm someone. They should understand it is very important to have a properly designed snow guard system whether it’s a bar system or the individual guards that are glued to the roof.
Brion McMullen, SnoBlox-SnoJax: This is an easy question that can be answered in one word “spacing.” Our company has designed a generic online estimator program we hope will help set the industry standard for snow guard placement. SpacingTool.com enables the end user to instantly determine how many guards should be used on a particular project. This tool immediately produces free on-line layouts and price quotes that can be accessed multiple times with an email generated key code. The program features a user-friendly interface that only requires basic roof criteria and simple contact information. In addition, this website can be accessed from any Internet capable mobile phone, while on the jobsite, to obtain instant snow guard calculations.
Q. What are the advantages of the snow retention products you supply?
Stearns, Alpine Snow Guards: Alpine snow guards make snow retention devices for all types of roofs. Metal roofs can be standing seams, corrugated and through fastened and metal shingles. Alpine offers multiple solutions for snow retention for all metal roofs as well as all other roofs.
Salvatore, Berger Building Products: The name Berger has a rich tradition of manufacturing quality snow retention products. Berger Bros Co. began manufacturing snow guards with their first design, fittingly named the #1 model, back in 1893. Today, Berger Building Products, Inc., manufactures the most extensive selection of snow retention products in the industry with models for virtually any type of roof. Berger offers individual snow guards that can be mounted directly to standing seams and surface panels of metal roofs or under asphalt shingles, natural or synthetic slate, tile and cedar shake roofs. There are designs in copper, stainless steel, bronze, galvanized iron, clear polycarbonate and in a wide variety of stamped patterns and ornamental castings. There are many models can be ordered in a custom color. Berger also manufactures the only heavy duty-snow rail system with continuous coverage below the height of the standing seam.
Haddock, S-5! Solutions: They preserve roof warranties and are non-penetrating. We have the only system available with an optional lifetime warranty. In terms of holding strength, our systems are the strongest systems on the market and they are the most cost-effective systems available.
Nagaki, Snobar: We supply a bar system along with clamps that clamp on to metal standing seam roofs, therefore, they can be installed in all types of weather or temperatures. Another advantage is we can paint all of the major components to match the roof with a 20-year powder coat finish which is a scratch resistant & very durable finish.
Besides providing 30-plus years of quality products, our company offers two types of snow retention systems: individual pad style snow guards made from polycarbonate or metal and bar type systems manufactured from galvanized steel or aluminum. Contrary to popular belief, the height, width and shape of a guard or rail system does indeed affect its performance! Every one of our single pad style snow guards have a flat, “forward-mounted” face that measures at least 3 inches across and stands no less than 2.5 inches high. Our snow guards are usually installed in the lowest portion of the roofing panel where the snow and ice actually moves. Depending on the type of roof system and the owner’s preference, the polycarbonate pad style guards may be adhesive or screw mounted. On standing seam roofs, adhesive mounting offers a huge advantage over mechanically fastening because this method does not restrict the natural thermal expansion and contraction process of floating metal roof panels and in the event of severe snow-drifting conditions, it provides a release feature that eliminates the possibility of panel damage. Our high-end snow bar systems are unique in that the aluminum or steel bar systems can be painted to match the panel. The SnoBar is attached by crimping to the seams and has either a flat face or square tube with an ice stopper at least 3 inches wide and is mounted “perpendicular” to the panel flat. The shape of the bar and installing the correct type of ice stopping device is the key to keeping the snow and ice from going under and up over the rails.
Q. What are the limitations of your snow retention products?
Stearns, Alpine Snow Guards: Limitations with snow retention products vary from manufacturer to manufacturer. Alpine believes all snow retention products should be tested to failure on the roof type they are intended for use on. Given the capability of the guard on a given roof type, knowing roof pitch, rafter length, building design snow load and lengths of roof areas to be protected, a snow guard manufacturer should be able to provide a written recommendation for the use of the products they are selling. Buyers should beware; snow guards should have a published load test value and the snow guard manufacturer should be willing and able to share that test and a written recommended layout. Every snow guard has a defined load limitation whether the manufacturer is willing to test it or not. Snow guard manufacturers who are not willing to test or recommend the proper use of their systems create snow retention systems limitations. This being said, Alpine recommends that a local structural engineer get involved with any project that has a building design ground snow load of 150 psf or greater. Alpine will provide the structural engineer with allowable load data so that he or she can design a system specific to the building in regions with excessive snowfall.
Salvatore, Berger Building Products: When dealing with snow guards, it is important to know that one size doesn’t fit all. PVC & rubber roofing materials are difficult to work with for two reasons, pitch and installation. A majority of these roofs have pitches less than 2-1/2:12. Snow guards are designed to limit a snow slides momentum. On roofs with pitches less than 2-1/2:12, it is often better to allow the snow to creep over the side, rather than to attempt to hold it in place.
Haddock, S-5! Solutions:
We only produce products for metal roofing and not other roof types.
Nagaki, Snobar: Our snow guards are limited only to metal roofs so therefore we don’t have anything for roofs such as tile, shingles or membrane.
The metal snow guards can only be screwed down and occasionally there may be a noticeable dissimilar metal reaction that can take place between the guard and the roof when exposed to outside elements. Our company is not aware of an adhesive that works well with a metal snow guard mounted to a steel roof. While the adhesive method is preferred on floating panels, winter temperatures are not always favorable to obtain a proper cure of the adhesive. The SnoBar and ColorRail systems are capable of wintertime installation but not every panel seam can accept a crimp-on attachment and in some cases the high-end bar system can actually exceed the cost of the lower priced pad style snow guards.
Q. Please share a story of a unique snow retention application.
Stearns, Alpine Snow Guards: On a recent project at the NYC Public Library Alpine was contacted to see if we could reproduce an existing snow retention system for the project’s batten seam copper roof. Using our #225 brass system with a custom base plate and counter flashing mechanism we were able to replicate the existing system and provide a watertight connection. A similar application was recently carried out on a “Monel “ roof using a stainless steel base plate to isolate the “Monel” from the brass snow retention system.
Haddock, S-5! Solutions:
Cascade High School in a mountainous region of Idaho where 2 to 3 feet of snow can regularly accumulate on the roof. With this tremendous snow load, failure of the external gutter system was inevitable. Most gutters cannot bear the weight of freezing water, let alone the force of shedding ice and snow. Snow accumulations on sloped metal roofs can pose significant danger to property and life. The use of the S-5! ColorGard snow retention system led to a fast and economical retrofit that did not compromise strength needed to hold back falling snow. The contractor was able to complete the installation at about 30 percent of the cost of other snow retention systems.
Nagaki, Snobar: Back in December of 1996, we supplied our snow guard system for a solar panel company in California. They used our system to hold solar panels on a standing seam metal roof.
There is a high-rise building located in a busy downtown district in Virginia. They have concrete and metal window ledges around the entire perimeter of the building where the owners had a problem in the winter with snow and ice dropping off on the sidewalks below. The maintenance department called us for advice and we ended up recommending our large adhesive mounted Icejax II spaced 6 inches apart, staggered. The application was perfect and the building proprietors couldn’t be happier.