What is definition of wind gust factor CG?
Gust Effect Factor (Dynamic Response Factor) Cg. This factor accounts for the increase in the mean wind loads due to the following factors: • Random wind gusts acting for short durations over entire or part of structure.
What part of a roof is subject to the greatest wind uplift forces?
Roof overhangs are subject to wind uplift forces which could trigger a roof failure. In the design of the hurricane-resistant home, the length of these overhangs should be limited to 20 inches.
How do you calculate wind uplift on a roof?
The uplift force on each outer post is (1/2 the span projection + the outer overhang) * (1/2 the span width + the side overhang) = (25% of the roof area) * the net uplift (all the uplift minus the self-weight or ‘dead load’).
What is the building design return period for snow and wind loading in the Ontario Building Code?
50-year
While snow loads are typically based on a 50-year return period, there are no formal requirements currently for the assessment of the base climate variables.
How do you calculate gust factor?
For example, if the winds are reported at 18 knots, gusting 30 knots, it means you have a gust factor of 12 knots (30-18 = 12). So if you take half the gust factor, you get 6 knots (12/2 = 6). Yes, it’s math, but it’s really simple math you can do in the airplane.
How do you calculate wind load?
Armed with pressure and drag data, you can find the wind load using the following formula: force = area x pressure x Cd. Using the example of a flat section of a structure, the area – or length x width – can be set to 1 square foot, resulting in a wind load of 1 x 25.6 x 2 = 51.2 psf for a 100-mph wind.
What is the strongest roof design?
Pros: Hip roofs are one of the strongest designs for a roof. The inward slope on all four sides of a hip roof makes it an excellent design for both high wind and snowy areas. These designs also allow for more ventilation and grand vaulted ceilings or attics.
How do you design a wind load?
The design wind load shall be calculated as P = qhG CN (30.8-1) where qh= velocity pressure at mean roof height h using the exposure defined in Section 26.7. 3 G= 0.85 as gust effect factor.
