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SNOW LOAD
When it comes to choosing decking material, strength is an especially important factor for locations where it can snow…and snow a lot.
GeoDeck is incredibly strong. It withstands uniform loads almost 9 times higher than typical building code requirements, including safety factor, and deflection is well below ICC building code requirements.* That means whether you space your joists 12” o.c. or 16” o.c., your GeoDeck deck can withstand the heaviest of snowstorms.
*The typical uniform load building code requirement is 100 lbs./sq. ft. with a safety factor of 2.5 and ICC building code requirement for deflection should not exceed L/180 = 0.089" for 16" o.c. (under 300 lbs. concentrated load – for a stringent stair tread test.)
Traditional, S4S at 16” o.c.
TEMPERTURE 32° F |
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FLEXURAL STRENGTH (minimum): |
2,550 psi |
FLEXURAL MODULUS (minimum): |
450,000 psi |
UNIFORM LOAD at a break point |
2,680 lbs./sq. ft.* |
DEFLECTION under a snow load of 500 lbs./sq. ft.: |
0.046” |
TEMPERATURE -20° F |
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FLEXURAL STRENGTH (minimum): |
3,080 psi |
FLEXURAL MODULUS (minimum): |
623,000 psi |
UNIFORM LOAD at a break point |
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DEFLECTION under a snow load of 500 lbs./sq. ft.: |
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METHODOLOGY |
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UNIFORM LOAD
Engineering formula for calculating the limiting uniform load at a certain flexural strength of material:
W = 16x144xIS/(bhL2)
W = uniform load
I = 0.800 for GeoDeck board
S = flexural strength
b = 5.5” for GeoDeck (board width)
h = 1.25” for GeoDeck (board depth)
L = span o.c. (16” o.c.).
Simplified formula for GeoDeck boards at 16” o.c.:
W = 1.05xS
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DEFLECTION
Engineering formula for calculating deflection at a certain flexural modulus of the material:
D = 5xWxbL4/(384x144xEI)
D = deflection (in inches)
W = uniform load
I = 0.800 for GeoDeck
E = flexural modulus
b = 5.5” for GeoDeck (board width)
L = span o.c. (16” o.c.)
Simplified formula for GeoDeck boards at 16” o.c.:
D = 41xW/E
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