Snow Guards

What’s the worst damage you can do to a gutter?

“How about a mass of snow and ice that avalanches off the roof and takes the whole gutter system with it,” suggests Brian McMullen, a maker of roof-mounted snow guards.

Snow guards, then, are a critical element in protecting gutters from damage, especially when a home has a metal or slate roof. And to those who believe the snow guards are only for northern climes, McMullen says his company has sold its products in every state except Hawaii.

“Take a place like the Florida panhandle,” he says. “All it takes is just one snow to ruin your whole investment in a gutter system. In fact, sometimes it’s the southern states that can have real problems. They don’t anticipate snow and so they install gutters that aren’t made as strong.”

Paradoxically, though, McMullen has observed the gutter installers in general lack awareness about snow guards — even though “the number one reason for using them is to protect the gutter from being taken off the house.” Homeowners are increasingly aware of snow guards. Architects are learning the importance of specifying snow guards. Homebuilders and their roofing contractors are in the know. “But I think gutter installers also have an obligation to tell their customers about how to protect gutter systems from catastrophe,” he believes.

Public awareness of snow guards is increasing because a growing number of new products have been introduced. “For the residential market I sell most of my snow guards to homeowners, especially when the homeowner is having a problem with snow,” reports McMullen. “On the other, I don’t sell many snow guards to gutter companies. That tells me two things. First, installers aren’t very aware of snow guards. And second, homeowners who buy the products have a right to ask, ‘Why didn’t my gutter installer tell me about this problem?’”

Perhaps the reason for gutter companies’ lack of awareness is because snow guards are mounted on the roof surface, so that installers regard the product as outside their territory. Others may believe it is more profitable to move on and install another gutter system at another home, rather than spending the time to put snow guards on a roof.

“But the fact is that you can make money installing snow guards,” replies McMullen. “You get a wholesale price to buy 100 at a time, which is basically one house. The installation is easy. You just have to be comfortable walking on the roof. After that, you can earn a generous mark-up.”

Putting Snow on Hold
For gutter installers interested in adding snow guards to their product offerings, the first step is to understand how they work and how to choose among the many snow guards on the market.

Snow guards are roof-mounted at spaced intervals and in two or more rows near the edge of a roof. The idea is that, as snow and ice back up against the snow guards, it will harden and create a dam. In turn, the ice dam will prevent the mass of snow from sloughing off the roof all at once in a single avalanche.
While all agree how snow guards are supposed to work, how can gutter installers choose among the many different designs? “First, the face of the snow guards has got to be big enough to hold the snow,” advises McMullen. Minimum size, he suggests, is 2.25 inches high and 3 inches across. Second, he favors a flat face rather than a pointed design, since he believes the latter is more decorative than functional and does not hold back snow.

“The height and shape of the face of a snow guards determines its ability to hold back layers of ice and snow,” continues McMullen. “Snow guards need to be mounted in the lowest portion of a roofing panel where the snow and ice actually moves. The flat surface should stand at least the height of the seam, creating a connected field to hold snow and ice stationary until it can melt off safely.”

Snow guards not only come in different heights and with different faces. In addition, the face may stand up from the edge of the mounting base or from the middle, so the snow guards looks either like a letter “L” or an upside down “T.” Further, the L-shaped products can be designed so that the perpendicular face which holds back the snow is on either the forward or rear edge of the mounting base.

In other words, snow guards can be made so that snow and ice must either: pass over the surface of the mounting base before being halted by the perpendicular face; pass halfway over the mounting base; or encounter the perpendicular face first, so that snow and ice do not pass over the mounting base at all. McMullen endorses the latter design since, as he advises, “that means the weight of the snow pressing against the face will push the base even more securely onto the surface of the roof.” With the other designs, he believes, the weight of the snow against the face of the snow guards can cause the mounting base to pull away from the roof surface.

“The correct spacing and number of the snow guards is also important for the system to work properly,” McMullen relates. Manufacturers should provide tested spacing layouts based on the roof pitch, panel runs from the ridge to the eave, panel widths and profile, and the snow load for which the home is designed. Using these layouts as templates, installers can take a tape measure and easily mark out where snow guards should be mounted.

Snow guards can be mounted to the roof surface either with mechanical fasteners, adhesives, or tape. For his part, McMullen recommends that only adhesive mounting be used on floating-type standing seam metal roofs. “This doesn’t restrict normal thermal expansion and contraction of floating metal roof panels,” he points out, “and provides a release feature that prevents panel damage, and eliminates potential impairment to the seams.” In addition, he cautions installers against tape fasteners as anything but a very temporary solution.

Finally, gutter installers have a choice of materials for snow guards. Metal snow guards are available in colors that match roofing panels. However, McMullen suggests the aesthetic advantage of color-matching can be offset by the “sundial effect” of upright metal snow guards casting shadows on the roof. Metal snow guards can also become brittle in cold weather, he adds, and sometimes can produce rust-causing galvanic reactions with the metal roof.

The other choice of material is clear plastic snow guards, including polycarbonates that are stabilized against ultraviolet rays to inhibit yellowing and cracking. The material does not cause galvanic reactions and, because it is clear, does not cast shadows. On the other hand, home-owners and architects cannot color-match the clear plastic snow guards to their roofs. Yet color-matched snow guards and roof panels can fade differently over time “if the snow guards is not the same material as the roof, or was painted at the same time with the same type of paint,” responds McMullen.

He cautions further against the idea of installing snow guards only above, say, the front entranceway of a home.

“That’s a misapplication,” McMullen warns. “Snow guards only hold what’s above them and not what’s beside them. If you try to segregate the snow on a roof and only hold back the snow above a doorway, then that will put stress on the snow guards and might cause them to pull off. The imbalanced loading is detrimental to snow retention.”

It Even Snows in Florida
“Plastic is the most economical material, and from there you can go up to stamped metal and even solid cast metal,” confirms Michael Pietrzak, sales and marketing manager for a snow guards manufacturer in PA. “They can be custom-colored, or they can be UV-stabilized clear plastic. And some can have a low profile, while others are ornamental.”

An alternative to snow guards is also on the market, as several manufacturers now offer snow rails as a strip of metal that can span the entire length of a roof edge.

Though metal roofs spring immediately to mind as a market for snow guards and snow rails, Pietrzak cautions that asphalt shingle roofs can also experience avalanches. “It’s true that metal is more slick so that snow can slide, whereas asphalt shingles have a grain,” he explains. “But if you’ve got a mass of snow and ice on an asphalt roof, you can also get an ice build-up underneath that mass. So if there’s a mass of snow lying on a mat of ice, it could all slide off at once.”

Pietrzak agrees that proper spacing of snow guards is essential and that manufacturers can provide this information to gutter installers. He likewise concurs that snow guards can be mounted with mechanical fasteners, adhesives, or tape. Similarly, some products are designed to mount on the roof surface and others can be affixed to a metal-roof seam.

“It’s usually roofing contractors who sell snow guards to homeowners and who do the installation,” reports Pietrzak, “and with the increase in metal roofing, more architects are specifying snow guards.” In fact, he believes the emergence of residential metal roofing has raised consumer awareness about snow guards, as well. For that reason, he recommends that “gutter installers can sell snow guards too, something you can add to a gutter job and that protects the homeowner’s investment in your gutter system.”

Since snow guards are an accessory item, Pietrzak says the mark-up for installers is fairly good. “You’re up on the ladder already, installing the gutters,” he points out, “so why not try to sell snow guards?” Berger has sold snow guards for use “in every state where there’s even a chance of snow,” he adds. “Why, we’ve even sold snow guards for the roofs of bus shelters at Disney World in Orlando!”