A snow roof system should be designed and built to prevent a rooftop avalanche. Generally, the design of a snow roof system will be affected by whether or not the roof is made of a metal or a snow-resistant material. However, the design of a continuous or discontinuous snow roof system may also be affected by factors such as the direction of a thaw and the direction of the shear zone.
What You Will Learn
Prevent an unpredictable rooftop avalanche
Rooftop avalanches are a significant threat to the health and safety of people and property. The sudden release of snow from the roof is often catastrophic and can cause injury, death, and property damage.
A roof avalanche is a mass of snow, ice, and rock that falls from the roof, injuring people and vehicles. It can also tear away siding, vents, and windows.
Rooftop avalanches occur most often after a snowstorm. This is because the snowpack accumulates quickly on the roof. As the weather warms, the snowpack loosens. When the pressure of the snow is enough to break the bond, a large amount of snow can leave the roof at once.
To prevent an avalanche, install a quality snow fence or snow guard. These devices will keep the snow from sliding off the roof and let it melt more gradually.
Snow breaks are commonly attached to the flat part of the metal roof panel. These can be installed in single rows or in multiple rows. Proper spacing is essential when establishing a snow break.
Design differences between continuous and discontinuous snow roof systems
There is some debate as to whether the distinction between continuous and discontinuous snow roof systems is clear-cut. However, there are some design criteria to consider. In particular, the design of snow retention systems should be tailored to the specific application. It should be robust enough to resist the forces of a snowpack.
The simplest way to determine this is to conduct a series of tests. One test is a direct shear test that measures the effects of different everyday stresses. Another is a direct shear test that analyzes the effect of a varying ambient temperature.
Several other test protocols are required to come up with the perfect design. These include determining the most appropriate shear strength, the appropriate sliding force, and the optimal location for the snow retention system. Other considerations include the proper rafter length and the slope of the roof.
Similarly, the effects of normal stress on the shear strength of the ice-material interface are also investigated. It is estimated that the shear strength of an ice-material interface is at least one magnitude greater than the roof snow load. This is an important issue because a sudden discharge of tons of snow below eaves could cause catastrophic property damage.
Mounting a snow retention system to a metal roof
If you have a metal roof, you must have a snow retention system in place. This is important for safety and liability reasons. Your building can be damaged if the snow buildup is not properly handled.
A good snow retention system will allow snow to melt away, preventing the accumulation of dangerous ice and snow. Having one in place will also reduce your maintenance costs.
There are several types of snow retention systems for metal roofs. Each type is designed to work with the specific profile of your roof. These can include clamps, rails, and stick-on guards.
Clamps are a strong way to mount a snow retention system to your metal roof. They attach to your standing seam and use setscrews or fastening screws to penetrate the roofing material. Make sure the attachment is engineered to withstand service loads.
Rail systems provide a continuous snow retention option. They are typically made of aluminum and are attached to specialized clamps.