What are snow guards for roofs, and how do you install them?

If you've walked through a part of your city or town with lots of pitched, slate, metal or tile roofs , you may have noticed the small metal tabs sticking up along the bottom. These tabs, spikes or rails are called snow guards, and they're a safety feature designed to ensure large banks of snow and ice don't slide off the roof all at once.

When snow builds up on roofing, it can create an avalanche, where snow and ice all slide off and cascade downward, tearing off gutters and falling onto landscaping ... or passersby. Snow guards and rails are a roofing accessory that protects pitched roofs from this issue.

How do snow guards work?

Snow guards come in a few different types: tabs and rails are the most common. The tabs stick up slightly from the roof surface and break up sliding snow, causing it to come down in smaller pieces. These brackets protrude along the skirt of pitched roofs and hold up snow and ice, interrupting its flow. While snow may sink and fall between the spikes, they serve to keep large sections of snow and ice from falling all at once, which enables controlled melting on the roof.

Rails and bars work similarly to brackets, but hold whole sections of snowbanks in place at a time. Some systems have a few thin rails, while others use one thicker bar.  

How do you install snow guards?

Snow guards are installed differently depending on the roof type and guard type. With any snow guard you or your roofer chooses, it's important to follow the instructions carefully. Below, we rounded up a few of the common snow guard designs and how they're installed.

Slate roofs

Snow guards can be installed on new slate roofs or retrofitted onto old ones. Many are hung by hooking onto the same copper clout nails that hold up slate tiles.

Slate tiles are installed one over the next like scales. When you look up at a slate roof, you're only seeing the bottom portion of each tile. Traditionally, the tiles are nailed onto battens — long horizontal beams of wood — with two clout nails. Since nails can crack slate if they're driven in too tightly, there's usually some clearance. FixMyRoof, a roofing YouTube channel , demonstrates how slate tiles are hung.

The diagonal tab that you see rising from the roof is only the bottommost portion of the snowguard. A tongue of metal extends from this that has little notches along its side. The notches are sized to grab onto the shaft of clout nails. If snowguards are being retrofitted onto a slate roof, the roofer will slide this flat metal portion under the slate tile and fit the notch onto the clout nail, so that the snow guard lies in the right place. Further nail holes along this tongue can be used to stabilize the snowguard and prevent it from rocking. Since tiles are installed in orderly rows, with nails sunk into battens, these guards will form horizontal rows.

If slate tiles haven't yet been hung, installation of snowguards is simpler, as the guards can be nailed directly onto battens during installation. 

Snowguard manufacturer, Berger, publishes detailed guides that show how its products, like the Berger Snow Guard No. 100 , are meant to be installed. A Berger product representative demonstrates how its snow guards are hung on YouTube .

Metal roofs

There are many types of metal roofs . However, when folks talk about metal roofs, they often default to standing seam. Since there are no tiles on standing seam metal roofs, snow guards for metal roofs use a different logic. There are a number of systems for standing seam snow guards, but two of the most common are clamp-on brackets and bars with clips.

With clip systems, clips are installed directly onto the panel using adhesives or screws. While screwing into the panel is effective for mounting the clips, it requires you to drill into the metal, creating opportunities for water to seep inside, and also restricting the standing seam roof's ability to move with temperature fluctuations.

On the other hand, brackets clamp onto the seams of the standing seam metal. The brackets clamp onto the raised seam and hold a snow bar in place. Berger publishes a YouTube video showing how to install clamp-on brackets on a standing seam roof. 

Often, rails and guards are installed on screw-down roofs like Tuff Rib by drilling directly into the roof. If you or your roofer is considering drilling into your metal roof, it's important to check the guidance of the roofing manufacturer. Done incorrectly, screws could cause leaks and potentially void the warranty of your roofing system

Shingle roofs

Snow guards are less common on shingle roofs than they are on metal, slate and tile. This is due to a couple of factors: one, asphalt shingles grip snow better; two, shingles are more prone to snow and ice dams , so adding snow guards can sometimes make those problems worse if they're not installed carefully.

Snow guards for shingles attach similarly to slate. In fact, the Berger Snow Guard No. 100 (mentioned above) is designed to function with both slate roofs and shingle roofs, and can hook onto shingling nails just as it does with the nails used for slate. They can also be installed another way, by simply lifting the shingle, sliding the tongue under it and driving nails into the holes, fastening it to the roof decking . A Berger representative demonstrates how to attach No. 100 Snow Guards to a shingle roof in this YouTube video .

Tile roofs

Tile roof snow guards are available in various designs, just as tile roofs are. Terracotta or clay tiles often have a rounded design. However, tiles can come in many shapes and sizes, some flat, ribbed and otherwise. 

With all the design variations of tile roofs, tile snow guards vary in how they are installed. Some, like the Rocky Guard RG-Tile , use hooks to attach to the rear of the tile. On the other hand, Alpine Snowguards' PP235LS Three-Pipe Height Adjustable Snow Guard is designed with a curved plate that fits with Ludowici Spanish tile. These are designed to mimic the rounded profile of Spanish tile, blending in while extending hardware upwards to support rails. 

Choosing the right snow guard

There are many snow guards on the market, and often, the choice between these accessories will be purely utilitarian. You might choose reinforced guards or rails if your roof has a strong pitch and you live in an area that's prone to heavy snow. On the other hand, a home in an area with lighter snow may be able to get away with a simpler system.

It's also important to recognize that installing some guards, especially on metal roofs, may damage the roof. Before you have guards installed, be sure that the guards are compatible with your roofing warranty . 

That said, many snow guard manufacturers offer a range of designs with different visual appeals. Materials vary; it's possible to find snow guards that are made of translucent plastics that are meant to blend in, while others are downright ornamental. Some companies will even custom-paint hardware to match your roof. If you're invested in the look of your roof, we recommend shopping to find a snow guard that will match your home's design.

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