Commercially or residentially, metal roofs boast many positive features. They are very aesthetically pleasing and have the longest service life possible. However, there are some things you need to consider when thinking about your metal roof. If you live in snow country, then you are aware of the risk of roof top avalanches, caused by melting snow blankets slipping off of your roof. These avalanches can cause serious damage to property or persons. A quality snow retention system will help you avoid these drawbacks, allowing the snow to safely melt away, providing decades of trouble-free service of your roof.
Generally speaking, there are 3 basic methods available when considering snow retention systems:
- Mechanically attached- clamping to the seams of the roofs
- Penetrative Mechanically attached- screwing through the roof materials
- Chemically attached- “Stick-on” method with individual guards
Let’s take a closer look at the three different methods...
#1 Clamping Systems Clamps attach directly to the roof seam using polished, round-point setscrews that do not penetrate the metal (mechanically-attached). This method utilizes a seam-clamping attachment and is a secure option for standing seam style metal roofs. Common items that we offer to mechanically attach snow retention systems to metal roofs include S-5-U, S-5-V, and S-5-N clamps. You can also browse our complete line of S-5 attachment clamps for metal roofs by visiting our website.
- Avoids drilling holes that could leak and that might void your roof warranty.
- Clamp-to seam attachments will not fatigue due to thermal heating or cooling of the roof.
- Easily mounted even after the roof has been installed.
Considerations with Clamp Attachments:
When this method is used, the sliding force of the snow is transferred to the clamp and then into the roof panels themselves. The holding strength of such a system should be documented through rigorous testing and must be able to resist the loads to which it is exposed. These loads do vary from job-to-job. S-5! has tested their clamps with almost every metal roof profile available. You can view these results directly at S-5.com under the “Load Test Results” tab located at the bottom of the page.
#2 Penetrative Systems The second type of snow retention is a system that attaches through the roof and into the building structure (a penetrative mechanical-attachment).
- A strong, secure, and reliable method if properly designed, installed and waterproofed.
- Only suitable for a roof that is attached the same way (i.e. with screws that penetrate the roof’s surface, attaching it to the structure).
Considerations with Structure Attachment:
Holes or other penetrations will need to be drilled to anchor snow guard brackets to ensure secure placement and the long-term service life of the roof. If this is not done correctly, you run the risk of developing leaks. To accomplish this, prior to installation with other (non-S-5!) products, you will need to perform additional steps to waterproof these roof penetrations, and you will have to know something about sealant chemistry, part design, sealant selection/sourcing, etc.
The strength of the structural attachment mounting method is very important and should also be proven and matched to the in-service loads to which the snow guard will be exposed.
#3 Stick-On Systems The third type of snow retention is a stick-on, adhesive part. Some variations employ a factory-applied adhesive and others a field-applied one. Stick-on systems appear on the surface to be a very convenient and lower cost option.(chemical-attachment)
- Lower cost only when considering single part cost, not total job cost (e.g. labor, required guard quantity and distribution over the roof surface).
- Total cost needs to include replacement costs over the life of the roof. This is not “if”, but “when” the adhesive diminishes in holding strength and how quickly that happens – which then requires replacement. Adhesives all eventually diminish in holding strength with replacement time from one to eight years.
Considerations with Stick-on Attachments:
Installation is simple enough. These parts attach directly to the roof with a glued application. But if you look more closely at the detailed instructions, installation becomes a bit more complicated – careful surface preparation is required, as well as many days of curing time at specific temperatures. Stick-on snow guards typically have the lowest holding strength and usually continues to diminish with age. When they fail, they can rip away paint and protective roof coatings, causing corrosion. They also have the lowest lifespan because of the glue and/or plastic part being unable to handle the harsh elements and total exposure that is required on any roof (e.g. U.V., moisture and temperature change, etc.).
After reading through these three options, an important note to keep in mind with mechanically-attached systems is the distinction between clamping and drilling a system onto a roof. Drilling requires holes, and holes in a metal roof need to be properly weather-proofed to prevent leakage. On the other hand, S-5! offers clamps and brackets to reliably mount snow guard systems to metal roof seams without penetration. These clamps and setscrews compress the seam material against the opposite wall of the clamp – dimpling the material, but not penetrating it.
For roof profiles that do not allow this clamping technology, S-5! also offers penetrative attachments—but with some extra, vital features. The sealants we use for waterproofing the holes created are designed to last the life of the roof. They are also protected from harmful UV sunlight—and they utilize part designs that prevent over-compression which can also compromise their service life. AND we test and warrant their performance in accordance to ASTM E 2140.
Choose the right solution for your roof…
Snow melt can be unpredictable and dangerous in many situations. It is important to take the right steps to avoid rooftop avalanching. A secure and valuable snow retention system will ensure that both you and your property are protected against unwanted snow drifts. S-5! Has been manufacturing snow retention systems for over 25 years and would be a great place to start your search for the right solution. Unistrut offers S-5! clamps and retention systems available for convient purchase online. Please contact us with any questions you might have!