Snow Shed Roof
Your equation for determining snow load s x 1 25 p is fairly straightforward math.
Snow shed roof. Needed for severe weather conditions only. Sometimes the rafter will have a tail and extend out past the wall so that you have a soffit or overhang. This snow load kit is not necessary under normal snowfall conditions. Pooling water on a roof can cause leaks and other damage.
Each kit reinforces one roof truss. It makes sense when designing a metal roof to shed snow not to keep it on. When the snow piled up on the roof melting occurred and ice dams resulted in water ponding 3 inches deep. Since a shed roof generally has a much steeper slope it usually lets the water roll right down it and over the edge.
If you experience excessive snowfall in your area you can increase the snow load capacity of each roof truss of your 11 ft. They can be made of steel prestressed concrete frames or timber. You then have rafters running down from this ridge board and resting on the top wall plates. Some metal building manufacturers will not warranty a roof with a 1 4 inch slope.
Lots of built up snow adds extra weight to the roof that can also cause damage so shedding water and snow more efficiently is a definite advantage. S equals the depth in inches of the snow on your roof and p represents the pounds per square foot your roof is supporting. With expansion and contraction of the metal it is difficult to attach snow retention devices into the roof decking without causing a roof leak or slotting of the metal panel from the snow bracket fastener. It has a lower profile than the skillion or gable so may be more suitable to some neighborhoods.
To calculate the snow load on your roof assume that every inch deep of snow equals 1 25 pounds. We counted 90 stalagmites on the surface of the ice rink from drips coming from the leaking roof. These structures can be fully enclosed like an artificial tunnel or consist of lattice like elements. Slopes greater than 6 12 will tend to shed snow regardless of the texture of the material on them so roof slopes should be configured to avoid shedding anywhere people might be walking or exiting.
Lifetime shed from 16 psf without a snow load kit to 30 psf with snow load kit reinforcements. A simple roof to construct but slightly more expensive than the skillion due to the lower slope needing waterproofing. People have been killed by snow avalanches sliding off roofs during big snow winters. The higher the roof pitch the more often the snow slides off.
Metal roofs leak under these circumstances.