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Why Specify Snow Guard Retention?

WHY SPECIFY SNOW GUARDS FOR SNOW RETENTION?

There are several factors that one must evaluate when determining if a particular building requires a snow guard retention system. During the winter months, as snow accumulates on your home, gravity will begin to pull it down the slope of your roof. There are many reasons this can be harmful to your home or even dangerous. In worst structural cases, this can lead to damage to costly gutter systems, structural damage to lower roof levels, and even destruction of mature landscaping around the perimeter of a home.

Low-slope roofs with parapet walls naturally keep snow and ice on the roof. On a sloped roof, however, large chunks of snow and ice can slide off as the snow melts. Avalanching snow is probable on roofing systems with a steep enough slope and/or a low coefficient of friction. This is especially dangerous for pedestrians walking below.

SOME REASONS WHY YOU SHOULD SPECIFY SNOW GUARDS FOR ROOF SNOW RETENTION:

  1.  Damage/Injury – People and property can be struck by snow and ice falling from the roof. Property damage and injuries, even deaths can occur when snow is not properly retained on a roof.
  2.  Limited Access – Entrances to buildings can be blocked by snow and ice that falls from a roof.
  3. Roof Damage – When snow and ice masses slide off a roof, costly damage occurs.

CHOOSING THE RIGHT SNOW GUARD AS A SNOW RETENTION SYSTEM

There are many types of roofing materials, each has advantages and disadvantages and each should be considered when determining the placement of snow retention on the building.

When considering whether to install a snow retention system on your roof, you may first want to consider what type of roof you have. Will your roof allow snow to slide? Probably. In places with heavy snows, like areas in Utah, it is common for snow to slide off of all types of roof systems, leading to heavy ice and snow build up in gutters, which causes damage over time. If you have a metal, tile, slate or membrane roof with a pitch of 1/12 or greater, snow will definitely slide off and cause problems.

Engineered snow retention and solar mounting solutions

WE CAN HELP…

TRA snow retention systems are available for all types of roofs and come in a variety of options. The specific snow retention equipment recommended for your roof will depend on the type of roof system installed, the pitch of the roof, snow load, sheathing type, how old the building is and budget.

Our snow fences, brackets, and clamps are all types of snow retention systems that prevent large sheets of snow or ice from falling off a pitched roof. The systems hold the snow on the roof so it can gradually melt off, preventing damage to people and objects below.

At TRA Snow and Sun, we engineer and layout each project free of charge using the unique factors specific to your project. TRA Snow and Sun representatives will work with you to design the most efficient snow retention system. We can design your roof to work with a variety of applications. Just give us your project details & we will design your Snow Retention System to fit your project. For more information call TRA Snow and Sun at 801-756-8666.                                                                                                           

                                                                    REQUEST A QUOTE

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Snow Retention The Invisible Code

Snow retention codes do not seem to be a priority in the United States’ roofing industry. But it is very common to see snow and ice sliding off of a metal roof’s slippery surface. Snow and ice crush cars, and damages the roof, gutters, and landscape.  In some cases, snow and ice cascading off roofs have killed people. Codes for snow retention systems are essential to protect people and property from sliding ice and snow.

There are many reasons snow retention systems fail and why we need codes in place.  Some examples are:

PRODUCT FAILURE

snow retention system

This snow retention system was not engineered for some variable of the project that caused it to fail.

The snow guard was not strong enough to hold the load it was carrying.

Anyone can cast a wax snow guard, spread some adhesive on the bottom, and tell the consumer how to install it without any testing of the product or the system. Codes would provide a standard to ensure adequately designed products are utilized.

SHEATHING/ROOFING MATERIAL FAILURE

Roofing material is inadequately secured for the shear created by sliding snow.

If the roofing material is not securely fastened to the deck (specifically on standing seam metal roofs), added weight can cause the standing seam metal roof to slide right off, along with the rest of the roofing material and snow retention system. There is a code requirement in place for wind uplift on standing seam metal roofs, but not for shear strength.

Screws or fasteners pull out.

sliding snow and ice

Sliding snow can be incredibly dangerous.

When installing snow retention on roof sheathing, the thickness and type of the sheathing determines the fastener pull-out strength.  If one is installing a snow retention system on 7/16-in. OSB board, the fastener will fail more quickly than when using ¾-in. plywood.  (See chart below.) When designing a layout for a project, many snow retention manufacturers do not test for these variations.  If the snow retention system was designed for ¾-in. plywood and the project is using 7/16-in. OSB board, the whole system needs to be redesigned.

The fastener does not penetrate the sheathing.

If the fastener/screw is not penetrating the sheathing, the snow guard will not have the holding strength for which it was designed.

 

 

ADHESIVE FAILURE

plastic snow guards

These plastic snow guards fell to the ground because the adhesive did not bond properly

When using an adhesive, if the surface is not free of dust, dirt, oil, or waterproofing; or it is not clean and dry, the adhesive will not adhere properly.
If the temperature is not above 50 degrees F, the sealant will not cure. If a load is placed on the snow guard before the 28-day cure time, the snow guard is more likely to fail. (This is according to the Technical Data Sheet  for SB-190)

SYSTEM FAILURE

The system is not designed for the roof slope and snow load.

When designing a snow retention system, factors change from project to project: the slope, roof type, sheathing type, and roof snow load.  If the snow retention system is not engineered for the variables of the project, it can fail.
Most snow guards are not tested to the fail point of the system.

Many snow guard manufacturers claim theirs are tested, and many of them are, but they are not tested to the fail point of the entire system.  The product may be tested to maintain its shape, but was it tested to stay on the roof?  It’s great if the product stays in one piece, but not if the fastener fails, the adhesive fails, and the sheathing fails.

snow retention code

A snow retention code needs to be put in place to help prevent injury to people and damage to property.

INSTALLATION FAILURE

The product was not installed to manufacturer’s specifications.

The manufacturer’s instructions need to be followed meticulously in order to ensure safety and to keep warranties in effect.  Many manufacturers have specific torque requirements, placement, and maintenance instructions.  If these instructions are not followed, the system can fail and the manufacturer is not at fault.

Obviously, there are valid reasons why the United States should establish codes for snow retention on roofs.  Why hasn’t this happened?  A few reasons could be:

  1. Snowfall occurs in certain areas of the country but not nationwide; therefore, the demand for codes is minimal.
  2. Not many deaths occur due to ice and snow sliding.
  3. Property damage is localized.
  4. The insurance industry is not pushing for this type of code.

There are many other codes in place to protect people and property; so why not for snow retention?  We have codes for wind uplift and ICC test standards for product failures due to wind and moisture penetrations, to name a few.  How many life threatening events need to occur before we do the right thing when it comes to a code for snow retention on roofs?

It’s time to make the invisible snow retention code visible.

References

  1. Surebond Technical Data Sheet SB-190.

About the author

Terry E. Anderson has been in the roofing industry for over 35 years. He is the owner of Anderson Associates Consulting and president of T.R.A.-MAGE, Inc., a manufacturer of roof snow and sun accessories. Anderson was sought after to solve tile roof problems, eventually researching solutions to the frequent structural damage caused by sliding snow and ice. Traveling to Europe, Terry studied how the roofing industry there successfully dealt with snow and ice issues. Using his years of experience and research, he coauthored Concrete and Clay Tile Roof Design Criteria for Cold and Snow Regions. Anderson founded T.R.A. Snow and Sun, now in partnership with MAGE and known as T.R.A.-MAGE, and is recognized as a leader in snow retention systems. He is a member of RCI, WSRCA, and on the technical committee for the Tile Roofing Institute (TRI).

Published: Interface Dec 2011

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Snow Guards With A Fresh Look To Color Hardware

Take a look at these pictures for a fresh new snow guard clamp-on look. Our black Xylan hardware is now available for any colored clamp-on. Would this be your new snow retention look? Tell us by a simple comment on our contact page

Color Trends…

OUR PAINTED XYLAN BLACK HARDWARE!

XYLAN BLACK HARDWARE BENEFITS

    • New specialized color option for any colored clamp-on
    • Full paint application extending to the entire bolt thread
    • They’re resistant to heat and wear
    • Improves the functionality and life span by reducing the amount of wear 
    • Adds protection from corrosion
    • Stand out with a UNIQUE bold look 

WE CAN HELP…

TRA snow guards for snow retention systems are available for all types of roofs and come in a variety of options. The specific snow retention equipment recommended for your roof will depend on the type of roof system installed, the pitch of the roof, snow load, sheathing type, how old the building is and budget.

Our snow guard snow fences, brackets, and clamps are all types of snow retention systems that prevent large sheets of snow or ice from falling off a pitched roof. The systems hold the snow on the roof so it can gradually melt off, preventing damage to people and objects below.

At TRA Snow and Sun, we engineer and layout each project free of charge using the unique factors specific to your project. TRA Snow and Sun representatives will work with you to design the most efficient snow guard retention system. We can design your roof to work with a variety of applications. Just give us your project details & we will design your Snow Guard Retention System to fit your project. For more information call TRA Snow and Sun at 800-606-8980.                                                                                                

                                                                    REQUEST A QUOTE

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Why Specify Snow Guard Retention

WHY SPECIFY SNOW GUARDS FOR SNOW RETENTION?

There are several factors that one must evaluate when determining if a particular building requires a snow guard retention system. During the winter months, as snow accumulates on your home, gravity will begin to pull it down the slope of your roof. There are many reasons this can be harmful to your home or even dangerous. In worst structural cases, this can lead to damage to costly gutter systems, structural damage to lower roof levels, and even destruction of mature landscaping around the perimeter of a home.

Low-slope roofs with parapet walls naturally keep snow and ice on the roof. On a sloped roof, however, large chunks of snow and ice can slide off as the snow melts. Avalanching snow is probable on roofing systems with a steep enough slope and/or a low coefficient of friction. This is especially dangerous for pedestrians walking below.

SOME REASONS WHY YOU SHOULD SPECIFY SNOW RETENTION SYSTEMS:

  1.  Damage/Injury – People and property can be struck by snow and ice falling from the roof. Property damage and injuries, even deaths can occur when snow is not properly retained on a roof.
  2.  Limited Access – Entrances to buildings can be blocked by snow and ice that falls from a roof.
  3. Roof Damage – When snow and ice masses slide off a roof, costly damage occurs.

CHOOSING THE RIGHT SNOW RETENTION SYSTEM

There are many types of roofing materials, each has advantages and disadvantages and each should be considered when determining the placement of snow retention on the building.

When considering whether to install a snow retention system on your roof, you may first want to consider what type of roof you have. Will your roof allow snow to slide? Probably. In places with heavy snows, like areas in Utah, it is common for snow to slide off of all types of roof systems, leading to heavy ice and snow build up in gutters, which causes damage over time. If you have a metal, tile, slate or membrane roof with a pitch of 1/12 or greater, snow will definitely slide off and cause problems.

Engineered snow retention and solar mounting solutions

WE CAN HELP…

TRA snow retention systems are available for all types of roofs and come in a variety of options. The specific snow retention equipment recommended for your roof will depend on the type of roof system installed, the pitch of the roof, snow load, sheathing type, how old the building is and budget.

Our snow fences, brackets, and clamps are all types of snow retention systems that prevent large sheets of snow or ice from falling off a pitched roof. The systems hold the snow on the roof so it can gradually melt off, preventing damage to people and objects below.

At TRA Snow and Sun, we engineer and layout each project free of charge using the unique factors specific to your project. TRA Snow and Sun representatives will work with you to design the most efficient snow retention system. We can design your roof to work with a variety of applications. Just give us your project details & we will design your Snow Retention System to fit your project. For more information call TRA Snow and Sun at 801-756-8666.                                                                                                           

                                                                    REQUEST A QUOTE

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Why Snow Guards Fail…

Imagine (or maybe you don’t have to imagine!) that you are an able-bodied adult male.  If you were asked to keep a hold back a parked car from rolling down a gently sloped hill, you could probably do it, right?

Now imagine that you are in the direct path of a car coming down the same hill at 40 m.p.h.  Would you be able to survive such an impact?  Of course not.

Why should you expect a tiny snow guard to stop a heavy, moving ice and snow avalanche anymore than you could expect yourself to stop a fast moving car?

This scenario might seem a little comical, but in reality, it isn’t funny.  Lives are lost each year due snow and ice avalanching off a roof and landing on someone below.  Keeping the snow and ice on a roof isn’t accomplished by placing one or two rows of snow guards at the edge of the roof.

How do roof avalanches start?

Roof snow melts into water which then runs underneath the build up of snow on the surface of the roofing product.  If there is enough water flow, the snow and ice release from the friction of the roofing product and an avalanche begins.   If snow guards are placed throughout the roof area, protruding up three or more inches from the roofing product, then when the snow melts into ice, the field of snow and ice will freeze in place around the projections and prevent the ice from sliding off in a sheet.  If the snow guards aren’t spaced close enough and spread throughout the roof, you will get an avalanche of heavy snow and ice.

Snow Avalanche Off A Roof

Roof snow guards frequently fail because critical factors are not taken into consideration.

  • The snow load. How much snow will fall on this roof?  How much does it weigh?  This data is available online and from the building department.
  • The roof’s slope. A steeper roof will need more snow retention products.
  • The type of roofing material. Each type has its own unique factors as to how the snow slips off.  Each type will need a different type of snow guard.
  • The method of fastening. Are nails, screws or adhesives used?  Each type can pull out at varying rates. Plastic snow guards are generally attached with adhesive which must be attached to a clean surface under optimum temperatures.
  • The sheathing type. This is important because fasteners pull out at varying rates based on the type and thickness.  Many snow guards fail because fasteners and sheathing type/thickness are not considered.

 

Snow guards should be designed for the roof type (asphalt, metal, shake, tile) and should be attached securely and effectively for the sheathing type.  The effectiveness of a snow retention system relies on each of these unique factors. Factoring in each item results in snow guards arranged throughout the roof area in an exact layout which, when working together as a system, prevent uneven loads and eventual avalanches.

Other reasons for snow guard failure

  • Force loads are too high for the snow guard and its attachment system. When snow gets moving, it’s like a speeding car going downhill.  A couple of snow guards haphazardly placed with little consideration to attachment pull-out rate or sheathing thickness or slope and snow load, just like one man, can’t stop it.
  • Weight of the snow and ice in a given space. It’s important to place the snow guards all over the roof based on how much weight is expected.  As snow melts and ice freezes around the part of the snow guard that sticks up from the roof (at least 3 inches is best), the whole field of snow/ice is anchored in place on the roof and less likely to slide off, but only if this layout is specifically engineered based on the specific factors.

 

In conclusion, the right layout and installation of snow guards work against the force of heavy snow. Too few snow guards will fail unless you have an engineered layout with the correct calculated number of snow guards than you can stop avalanching.

If you can’t remember all the details, just think about how hard it would be for one man to hold back a car and how it’s just as impossible for a couple of snow guards attached randomly to hold back an avalanche of snow. Then call us and we’ll do the calculating and engineering for you!

TRA Snow and Sun Announces New Cost-Saving Deck Mount Snow Fences

TRA Snow and Sun, Inc., is now offering new Deck Mount Snow Fence designs that will save the end user money.

TRA Snow and Sun, Inc., well known for their Snow Bracket snow guards and engineered snow retention system, has developed new lower cost deck mount snow fence called the Mount Shasta and Diamond Mount.

Terry Anderson, President, explains why the company, which also offers individual snow guards and other snow fences, decided to expand their product line.  “Our other snow fences have been very successful but we wanted to provide a less expensive option.  The Mount Shasta Deck Mount fits this need while still providing superior protection from sliding snow and ice.”

snow fence, snow retention, heavy duty snow fences, snow rails

The new deck mount system is designed for installation on most stick framed roof types and works with 3/4” X 3/4” square fence pipe (Diamond Mount style) or 1” (1.315”OD) fence pipe (Mount Shasta style).  Customers can choose from one or two rail designs.

The engineers at TRA Snow and Sun always take the snow load, slope of the roof and roof type into account when calculating how many snow fences are needed and how far apart they are placed on the roof.   The heavier gauge, larger snow fence mounts as well as this new mount are considered for each job.

All three factors determine which snow fence system is recommended.  If, for instance, a roof calculates out to require 1.2 fences from eave to ridge using TRA’s original deck mount snow fences, then two fences are specified because you cannot disregard the need for the .2 of a fence that would hold back snow.  If the new Mount Shasta deck mount snow fence calculates out to 1.8 fences from eave to ridge, that would also mean two snow fences, but the new snow fence clamp is less costly, still ensuring a safe system with less expense to the customer.

The Mount Shasta and Diamond Mount Deck Mount Snow Fences are available in steel, copper and Cor-Ten®, with finishes in raw steel, electro-galvanized steel, hot-dipped galvanized steel, mill finish copper, mill finish Cor-Ten®.  Powder coating is available. These snow fences are used on: asphalt shingle, cedar shingles, flat seam metal, granule metal, metal panel, slate simulated slate, tile roofs and woods shakes.

TRA Snow and Sun, Inc., located in American Fork, Utah, offers Roof Snow Retention Devices, Solar Mounting Systems and Roof Flashing Solutions. They supply to all types of customers, from the individual homeowner to the big developer and offer free engineered designs of all their systems. For more information call Jacob Anderson at TRA Snow and Sun at 800-606-8980 or visit https://trasnowandsun.com/product-category/snow-retention/.

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