What is a snow guard? Why do I need one on the roof?
The snow guards imply is a special roof safety system that is installed on the roof of the house. Snow retention is designed to retain snow and prevent its sudden avalanche descent.
Snow retainers (stoppers, holders, catchers) are essential elements of a safe roof; in practice, they perform two main basic functions:
- Keeping snow cover on the roof for the purpose of thermal insulation.
- Prevention of a sudden slide of the snow mass from the roof during its melting.
Is there a case when snow guards are not required?
Roof safety devices are not required on the roof in the following cases:
- There is no snow in your area, only minor precipitation.
- The roof is flat and heavy snow loads are not expected in this region.
In all other cases it is highly recommendable, especially on metal roofs, to have snow stoppers installed on the roof top. Otherwise, the snow mass streaming down from the roof can damage the gutters, the landscape, cars, seriously injure the passers-by.
Why do snow guards get ripped off the roof?
We do not consider the cases with plastic snow holders which are glued to the roof covering. For obvious reasons they cannot withstand the snow load and easily get broken. But if you have solid metal tubular snow guards and they were torn off you might want to look into reasons laid out below.
- Incorrect installation, wrong fastening of the supports. When installing the snow fence, it is important to strictly adhere to the installation rules: it is prohibited to fasten the bracket just to the roofing material (straight rib panel, metal shingles or metal tile). The proper way would be to use special self-tapping screws from the kit and fasten the retention system to the strapping, the places where the fastening screws pass through the metal tile must be sealed with special rubber gaskets.
- Wrong calculation of the number of rows of snow holders. The snow load on the roof will be different in relation to the snow area, the length and angle of the roof slope. Therefore, depending on the listed parameters, sometimes it is recommended to install snow guards in 2 or even 3 rows if necessary.
How do I know what is the right place to install the snow guards?
It is necessary to correctly determine the areas for installation, since even pitched roofs might not need the snow guards in the regions with no snow.
As a rule, snow-retaining structures are installed on the roof slopes above the entrance to the premises, at each level of multi-level roofs, above ventilation pipes and dormers.
On flat roofs (for example, verandas), on canopies above the entrance and other sheds, roof snow guards are mounted in the middle part of the slope so that part of the snow mass does not deform the flat roof itself when it slides down the roof.
How do I determine the snow load of the roof?
To exclude the chance of error, it is better to leave this job to professionals. If you want to know roughly the snow load, consider the snow depth in feet. Once you know the number multiply it by the weight of a cubic foot of snow. Let’s see the example: you found out that snow weights 20 pounds per cubic foot and then you see that there 2 feet of snow on the roof. After multiplying the numbers, we will find out that each square foot of the roof can withstand 40 pounds of load.