Calculators
Snow drift loading Adjacent to Roof Obstructions
version 0.0.4
February 8, 2023
February 8, 2023
Thinking...
Ca(0) = 0.67*γ h/(CbSs = 2.513
xd = 2h = 2 m. But 3 m ≤ xd ≤ 9 m:
h' = h - CbCwSs/γ = 0.733m
Specified Snow Load
[4.1.6.2]
S = Is[Ss(CbCwCsCa)+Sr] Factors
User input values:
Importance Factors
Roof slope = 0 degrees
Slope Factor
Ss = 1
Sr = 1
ULS: Is = 1.25
SLS: Is = 0.9 Slope Factor
For non-slippery roof:
Slope <= 30 degrees.
Cs = 1
Slope <= 30 degrees.
Cs = 1
Cb = 0.8
Density = γ = 3 kN/m3
[Structural
Commentaries
Fig G-8]
Commentaries
Fig G-8]
Drift Factors & Distribution
Ca(0) = 0.67*γ h/(CbSs = 2.513
a) when Ca(0) < ( 0.8/Cb=1 ) : Ca(0)=0.8/Cb
b) when Ca(0) > ( 2/Cb=2.5 ): Ca(0)=2/Cb
b) when Ca(0) > ( 2/Cb=2.5 ): Ca(0)=2/Cb
Ca(0) = 2.5
xd = 2h = 2 m. But 3 m ≤ xd ≤ 9 m:
xd = 3 m
h' = h - CbCwSs/γ = 0.733m
Min dist where (Cw = 1.0) = 10*h' = 7.333 m
Obstruction effect limit = 3 Ss / γ = 1 m
Snow Load Summary
( b = 10 m ) > ( 3*Ss / γ = 1 m )
x = 0
Cw = 1
Ca(0) = 2.5SULS = 1.25[1(0.8*1*1*2.5)+1] = 3.75 kPa
SSLS = 0.9[1(0.8*1*1*2.5)+1] = 2.7 kPa
0 < x ≤ ( xd = 3m )
Cw = 1
Ca(x) decreases linearly over 0 < x ≤ xd
Ca(x) = 2.5 - 0.5 * x (with x in meters)
Ca(x) decreases linearly over 0 < x ≤ xd
Ca(x) = 2.5 - 0.5 * x (with x in meters)
x = xd = 3m
Cw = 1
Ca(xd) = 1SULS = 1.25[1(0.8*1*1*1)+1] = 2.25 kPa
SULS = 0.9[1(0.8*1*1*1)+1] = 1.62 kPa
x > ( xd = 3m )
Cw = 1.0
Ca(x) = 1SULS = 1.25[1(0.8*1.0*1*1)+1] = 2.25 kPa
SSLS = 0.9[1(0.8*1.0*1*1)+1] = 1.62 kPa
By using Jabacus or information derived from this Service, you have agreed to the Terms of Service.
This information must be read or used in conjunction with Part 4 and the Structural Commentaries of the NBCC 2005. In the event of discrepancies, Part 4 and the Structural Commentaries of the NBCC 2005 shall govern.
By using Jabacus or information derived from this Service, you have agreed to the Terms of Service.
This information must be read or used in conjunction with Part 4 and the Structural Commentaries of the NBCC 2005. In the event of discrepancies, Part 4 and the Structural Commentaries of the NBCC 2005 shall govern.