Problem 2.6

 

 

Tributary area to ridge beam 

 

AT = 13 * 22 = 286 ft2

Note that the dead loads calculated in Problem 2.1 were on a horizontal plane, so we use the horizontal distance of 13 ft instead of the hypotenuse.

 

Roof Live Load

 

Term Value Reference
L0 20 psf (at 0:12) ASCE 7 table 4-1
R1 1.2 - 0.001AT ASCE 7 section 4.9.1
R2 1 (F ≤ 4) ASCE 7 section 4.9.1

 

Lr = (1.2 - 0.001 * 286) * 1 * 20 psf = 18.28 psf  (pressure)

wLr = 18.28 psf * 13 ft = 237.6 lb/ft  (distributed load on ridge beam)