Snow load calculation is the process of determining how much weight a roof can carry. It is essential to know this information because it can determine whether or not your roof is safe to use. There are many things to consider when calculating the snow load on your roof.
The Basics
Many are asking what is snow load calculator and why it is essential for homeowners. Snow load calculations are an essential factor in determining the safety of a building’s design. Depending on where you live, you can utilize the methods and instructions outlined by ASCE in ASCE 7-10 to determine snow loads and how to apply them to your building. ASCE-7 has formulas to determine the snow drift load on a roof (wind collecting on the top due to snow accumulation against a verticle surface). The calculation can be tricky, but it needs to be considered to ensure your structure is protected from the effects of winter weather.
The snow loading formulas in ASCE 7-10 consider many factors, including roof slope, wind exposure, and roof surface roughness.
The Roof Pitch
The roof pitch of your home plays a huge role in how your roof withstands weather and how much snow it can sustain. It can also impact the type of material that your roof is built from. The best way to determine your roof’s pitch is to take a measurement. Measure the height or rise of your roof, then the run (the horizontal distance from the peak to the edge). You’ll need a measuring tape and a level. Ideally, you’ll start at the 12-inch mark on the bottom of your attic floor and end at the roof rafter. From there, you can calculate your roof’s pitch. You can do this manually or by using a pitch converter. Typically, the pitch ranges from 0.75 degrees for flat roofs to 30 degrees for steep roofs.
The Roof Material
The roof material you choose can greatly affect how much snow your commercial structure can handle. Asphalt shingles, metal roofs, and even concrete tiles are all great choices for large commercial structures in snow country. The load a roof can carry varies based on the type of snow it collects and how long it sits on your building. Generally, lighter snow covers will weigh less than heavier ones.
A good snow load calculator can tell you how much weight your roofing can carry based on location, climate, and other factors. This will help you decide whether your structure is built to withstand winter weather or should be redesigned for better snow handling. Many factors, such as the slope of the roof, building use, thermal factor, wind exposure, and friction from roofing materials, can impact snow on a roof. In late Winter and early Spring, when there is an accumulation of ice and dense snow on the lower layers of your roof, this can add significant weight to your snow load.
The Snow Density
Snow is a porous medium dominated by air pockets, and the density of new-fallen snow varies considerably. It can be very light – about 7% water content – or heavy – about 11% water content – depending on temperature, wind exposure, and moisture. It can be dense enough to cause structural damage if a large amount of it lands on a roof. That’s why it’s essential to know how much snow is on the roof – and how it’s distributed.
A common way to measure the density of new-fallen snow is by using a depth probe. This measures the weight of the snowpack per square foot, and if the depth is known, it can be used to estimate how much water is in it.
