Unbalanced Snow Load on Gable Roof (ASCE 7 7.6.1)
The ASCE 7-22 7.6.1 unbalanced gable case: windward slope drops to 0.3 ps while the leeward carries ps plus a wind-blown ridge drift surcharge (hd gamma/sqrt(S)). Applies only in the ~1/2:12 to 7:12 slope band with W > 20 ft; sizes the leeward rafter and ridge the balanced case misses.
Formula and source
gamma = min(0.13 pg + 14, 30); hd = 0.43 W^(1/3) (pg+10)^(1/4) - 1.5; windward = 0.3 ps; surcharge = hd gamma/sqrt(S) (S = 12/rise); leeward_peak = ps + surcharge; extent = 8 hd sqrt(S)/3.
The ASCE 7-22 Section 7.6.1 unbalanced snow load on gable/hip roofs, by name.
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