What is snow load psf?
Collect and weigh 1 cubic foot of snow (1 foot high x 1 foot wide x 1 foot long). Then estimate or measure snow depth on the roof. If your cubic foot of snow weighs 11 lbs and you have 2 feet of snow on the roof, then you have about 22 psf of snow load on your roof.
What is a good snow load for a roof?
10-12 inches of fresh snow melts down to about one inch of water. Most roofs can support about 40-45 inches of fresh snow. Packed snow is more dense than fresh, fluffy snow. Therefore, a roof can support about 20 inches of packed snow.
Does live load include snow load?
Live loads are those loads produced by the use and occupancy of a building or structure and do not include construction loads, environmental loads (such as wind loads, snow loads, rain loads, earthquake loads and flood loads) or dead loads (see the definition of “Live Load” in IBC 202).
What is the snow load for Ottawa?
2.32 kilopascals
The OBC 2012 Part 4 50-year return period specified basic snow load for Ottawa is 2.32 kilopascals (kPa), inclusive of the rain load. The corresponding Part 9 basic snow load is 1.72 kPa.
What does 30 lb snow load mean?
This downward imposed load on the home is also known as the snow load. The North Zone design live load equates to 40 pounds per square foot, the Middle Zone equates to 30 pounds per square foot, and the South Zone equates to 20 pounds per square foot.
How much snow can a roof hold in Canada?
According to the National Research Council of Canada, the minimum snow load a roof is required to handle is 21 pounds per square foot (or 1 kilo Pascal). Alberta’s building codes require a minimum of 22 pounds per square foot (or 1.06 kolo Pascals). For safety reasons, we build roofs that meet or exceed these codes.
What’s the difference between ground snow load and roof snow load?
Some snow is blown off the roof to the ground and some is melted by heat from the roof. In general, roof snow loads are somewhere between 50-90% of the ground snow load, depending on the exposure and heat transfer. Calculate unbalanced snow loads caused by sliding or drifting snow.
Can snow loads be reduced?
When the roof is sloped, the design snow load can be reduced by the roof slope factor, Cs, provided that the roof is unobstructed and there is sufficient space below the edge of the roof slope to accommodate the sliding snow. Obstructions to sliding snow can include snow retention devices or other roof projections.