Project: Designer: Climatic Data. Online Books & Manuals Design Roof Snow Load (Ps) = 26.9 psf ("balanced" snow load) NOTE: Alternate spans of continuous beams and other areas shall be loaded with half the Building Official Minimum = design roof snow load so as to produce the greatest possible effect - see code. Snow loads acting on a sloping surface shall be assumed to act on the horizontal projection of that surface. It goes without saying that in a warmer climate, the snow load probably would be less, so you need to check your code book for live loads and dead loads in your region. Excel App. } Roof snow load is defined as the weight of snow on the roof surface used in design of the building structure (IBC, 2012). For warm roofs that do not meet the aforementioned conditions, the solid line in Fig. For dead loads… document.write(''); For cold roofs with Ct = 1.2 and an unobstructed slippery surface that will allow snow to slide off the eaves, the roof slope factor Cs shall be determined using the dashed line on Fig. GD&T Training Geometric Dimensioning Tolerancing Snow Load Calculations. loads on roof. The dead load consists of the actual weight of materials that comprise the roof, plus any fixed equipment that the roof … If you have any concerns as you are determining your flat roof snow load, consult with a structural engineer or roofing specialist. Leeward Snow Drifts - from adjacent higher roof Upper roof length lu = 100.0 ft Local building codes dictate the snow load required for residential roofs. \({h}_{c}/{h}_{b} = 13.8 ft/1.17ft = 11.8 > 0.2\) and therefore, snow drift loading is necessary. n. Roof slope. Medeek Design assumes no liability or loss for any designs presented and does not guarantee fitness for use. Figure 2 shown below depicts the balanced snow load of 21 psf applied to the roof of our structure. from Eave to Ridge, W: ft. Horizontal Distance from Eave to Ridge: Type of Roof { For example, a roof with 3 feet of light snow has an estimated roof load of 60 pounds per square foot (3 ft depth X 20 lb/ft2/ft depth density = 60 lb/ft2). 1) Basic wind 2) Wind importance factor 3) Wind exposure 4) The applicable internal pressure coefficient 5) Components and cladding Windward snow drifts occur when wind blows snow from a lower elevation roof towards the wall of an adjacent, higher roof.