Clamp on snow brakes for metal roofs:
How to select & install snow fences & snow brakes on a standing-seam metal roof. This article describes mechanically-attached snow brake systems intended for use on standing seam metal roofs - a system that can also be adapted for use on some other roof types. We provide step by step snow brake installation details and we describe some roof snow guard installation snafus that can occur if proper connectors, parts, or installation instructions are not obtained & followed.
This article describes snow retention systems for smooth-surfaced roofs such as glass roofs, plastic roofs and metal roofs. We describe both glue-on snow guards and the types of clamp-on snow fences for these roof systems.
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Here are metal snow guards clamped to the steams of a standing seam metal roof. These snow guards are not installed following the recommendations of some manufacturers who suggest their guards be glued to the pans centered between the standing seams.
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We like this implementation: snow guards are clamped directly to the standing seam on the roof - no holes are made in the metal roof surface, and we avoid the problem of snow guard creep: glued snow-guards that creep down or fail to adhere to the roof surface.
These snow guards look like and probably are the painted cast aluminum RT SNow Guards produced by Berger Building Products.
Berger also provides clear plastic snow guards that can be adhered to the roof surface mechanically (via 4 pre-drilled screw holes) or by adhesive but as you'll read at SNOW GUARD GLUE ON INSTALLATION drilling holes in the roof is likely to lead to more than one sort of trouble.
We spoke with the occupants of this building in Poughkeepsie, New York about their experience with this installation. The staff confirmed that in eight years of winter snow collecting on the roof, this snow retention system had functioned without fail - important because customers park their cars quite close to the eaves of this building.
Using the S-5!® Sno-Guard snow brake system involves fastening a mounting block onto a standing seam on a metal roof. A clamp will connect the actual snow fence to the top of the mounting block. We will describe the mounting block position, proper location of its mounting screws, proper tightening torque, and connecting the block to the clamps and snow fence. Following the manufacturer's instructions we illustrate the step-by-step installation of a snow brake or snow guard on a metal roof.
Examples of what can go wrong with this system are discussed separately at Patented clamp Snow Guard block - when a roofing supplier sent us a bucket of random parts and no instructions. Happily a call to the S-5!® Sno-Guard manufacturer found immediate and expert advice, instructions on what parts we needed, their proper names, a referral to a supplier, and links to written and video installation instructions.
With the manufacturer's help we proceeded to install the snow brake system on the standing seam metal roof shown here.
In the photo at above left, notice the proper position of the two allen screws in the mounting block: both go in the same side of the block, and the larger diameter bolt hole that will secure the clamp that in turn secures the snow fence itself faces in the "up-roof" direction.
Measure along the first standing seam on one side of the roof, from eave up to the distance where the snow guard or rail or brake is to be installed. This distance depends on the number of snow guards to be installed on the roof and which in the series you are installing.
Because we're testing glue-on snow-brakes on the lower eaves of this roof, the aluminum snow guard system was moved about ten feet up from those brakes.
Exact distance up from the eaves to the snow brake we were adding to this roof was 103" from the eaves, as you can see if you click to enlarge the photograph at left.
For rules of thumb on locating snow brakes & guards see SNOW GUARD SPACING & PATTERN.
Some manufacturer's guides suggest just pinch-clamping the string to the standing seams - which I found flimsy and in the way. I tied the string to an installed clamp at the properly-measured distance at the roof's left and right most standing seams.
Install the first mounting block at the measured distance up from the lower roof edge on the first standing seam on one side of the roof.
Install a second mounting block the same distance up from the lower roof edge (eaves) on the last standing seam on the opposite side of the roof.
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Torque the mounting block set-screws to the manufacturer's specifications. This is important as a too-loose clamp attachment risks loss of the snow brake system, damage to the roof, and damage to other building components from sliding snow and hardware.
The manufacturer provides an allen screw adapter that can be driven by a 1/4" socket stepped to larger sizes to fit your torque wrench if necessary (photo at above right).
At above right is a close-up of the torqued S5! clamp onto the standing roof seam. The seam deforms slightly and the clamp block ma be slightly askew but will straighten out when you bolt the blocks to the snow rail itself. We had to convert the manufacturer's specifications in inch-pounds to foot pounds to match our torque wrench (divide inch pounds by 12).
Stretch a string between the two mounting blocks you placed on the first and last standing seam on the roof to give a straight line for placement of the remaining mounts onto the rest of the metal roof seams.
At above left is a close-up of our green guide string installation. You can see my measuring tape marking the proper position for the mounting block nearest the roof edge to which the string is tied.
The photo at above right shows our string-aligned snow brake mounting blocks and in the foreground an installed section of the snow brake assembly.
We first placed the mounting blocks lightly onto the standing seams, and then used the actual snow brake rail with its fittings to slide the blocks into perfect position to align the fastening bolts with clamp holes by loosely screwing the bolt down through the rail into the clamping block, keeping the block just lightly touching the string.
These would be tightened to proper torque setting.
But if you're experienced and trust your string and the play in the snow brake fittings, you may find it's easier to manipulate the drill and torque wrench to tighten every clamp in place along the guide string before ever installing the snow brake itself.
While the mounting block is not yet properly rotated into position our photos below show how easily the Versa Clip mounting clamp slides onto the snow brake or snow guard.
Slide all of the versa clips onto the snow brake before starting your bolting operation, then slide the clips into their position properly space to line up with the mounting blocks that are bolted to the roof's standing seams.
Then there is the question of positioning the mounting block and the actual sliding Versa Clip clamp that connects the snow fence to the mounting block.
An important detail that was not obvious in the manufacturer's written instructions was the position of the snow guard Versa Clip clamp and its connection to the snow fence itself.
The mounting block has seven tapped openings. Along with the Versa Clip that clamps the snow fence to the mounting block there are quite a few possible orientations for these parts. A first-time installer may be doing some head scratching.
Above we show the snow brake, its Versa-Clip mounting clamp that slides along a groove in the snow brake's flat or bottom edge, and a mounting block in the wrong position. Don't do this! As shown above the snow brake support will be weaker than its design strength. The mounting block in the photo needs to rotate 180 degrees (red arrow) from the way it's shown in my wrinkled hand.
The manufacturer said to "face the clamp up-roof" but which side was the "face"? To answer the question we watched the company's installation video where the detail was shown.
In our photograph we see the mounting block, clamp, and snow guard fence in the proper orientation.
The upper roof slope is to the right in this photo. The mounting clamp slides onto the rounded grooved protrusion of the flat or lower portion of the snow guard, securing the clamp to the guard.
The up-roof side of the sliding clamp then bolts down onto the mounting block.
The end of the clamp into which the mounting bolt for the snow fence will be fastened goes "up-roof" as you can see in our Correct Mounting Block, Versa Clip & Snow Fence position photograph above.
The mounting block is rotated so that the bolt hole that receives the Versa Clip mounting bolt in on the up-roof position.
The allen screws that secure the mounting block to the roof seam have not been tightened and the bolt that secures the mounting clamp to the mounting block has not been installed.
In the photo above you see proper clamp and snow brake installation position though the photo may be confusing. The lower photo (towards the red (C) 2014 text) is the "Up-Roof" direction while the upper photo is the "down roof" direction.
Watch out: in the photograph above notice that free-running, un-supported projection of the snow fence past the end of the mounting block and clamp? Keep that unsupported snow brake projecting length to 4" or less.
Leave room for thermal expansion between otherwise abutting sections of the horizontal snow brake sections. I left about 1/2" and covered these with the otherwise useless (for this installation) half-clamps sent along by the roofing manufacturer.
We had two more clamps (luckily) so I installed the last segment of snow guard as an up roof snow damage protector for that plumbing vent that was smashed, dashed, and demolished by sliding snow last winter.
Really? The first time we tried installing a clamp-on snow rail provided by the manufacturer of the brown standing-seam roof shown above at our snow guard gluing procedure we ran into trouble because of missing and improper parts and of course missing instructions too.
Watch out: If you "guess" at installing a snow brake system you have a good chance of installing it improperly, risking failure and damage to the system and to the roof.
The metal roof supplier provided us with an S-5! snow guard system using aluminum rails intended to serve as a snow brake and a bucket of milled aluminum blocks and clamps along with allen screws and bolts to clamp the snow rails to the standing seams of the roof.
It was impossible to make use of the parts we received. To be clear, the problem was not with the design nor quality of the S-5! Sno-Guard system or its parts, which are excellent. The problem was that our supplier just tossed a handful of random parts into a bucket and shipped it along with the roof.
This patented S-5!® system uses a block that clamps to the standing seam of the roof and a clever flat aluminum slider intended to slide into a mounting groove on the snow guard rail. The same flat slider should bolt to the top of the clamping block.
We paid $400. for this in my opinion aluminum recyclable material. If you want to give it a try, contact the S-5!® Company at http://www.s-5.com/snow/ but be sure that you've got compatible parts before you start climbing the ladder
The number of clamps was too few in my opinion, and only one of the sliders provided was the proper shape to work with the clamping blocks and aluminum snow rail.
At left is a photo of the two styles of clamps provided for this product. We received one (count' em one) of the model shown at left - that one would have mounted the bar on the roof. The rest of the clamps in the package were backwards and did not fit the groove on the bar and were therefore useless.
Note: the snow guard clamp shown at left sports the wrong clip and the set screws are incorrectly placed on both clamps. In a proper installation both set screws are installed in the same side of the clamp.
The total width of the single bar, if we could have installed it was 2". Compare that with the taller multi-bar snow brakes and guards you see installed on older roofs. The system's connectors are quite strong, but is the bar big enough? And is there a warning about roof damage using a clamp system if the standing seam roof panels were not adequately secured?
By the way, the S-5@ company does produce multi-rail snow fence models that are perfectly functional if you follow the manufacturer's instructions including properly securing the metal roof to the roof deck, and if you have the right parts to assemble the system.
It's a bummer to schedule the job, carry your stuff up onto the roof, and only then discover that the parts don't work in any fashion. Sure you can give the manufacturer a call, and maybe they'd send the right parts in a few days. How's that for a contractor trying to schedule work and earn a living?
Maybe we can make something else out of this stuff but this bucket of parts and the aluminum rails were worthless as a snow brake until we obtain the proper clips from the manufacturer.
At left is a photo of the proper S-5! Sno Guard clip referred to properly by S-5! as the versa clip. That will work properly with the clamps and rails provided by the roofing supplier.
At this supplier, Clint Funderburk was particularly helpful in providing missing Sno-Guard versa-clips and in giving installation advice regarding the S-5! Sno-Guard system described here.. LM Curbs provides roof curbs, roof hatches, skylights, snow guards, snow retention systems, Solar PV Kits, Louvers, and a Roof Walk system for metal roofing.
Watch out: What happens if you defer installing snow guards on a roof where they're needed? Take a look at SNOW GUARD FAILURES and at PLUMBING VENT REPAIR and you can see both damage and how that damage was later repaired.
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