roof live load - residential light construction

huangyhg

roof live load - residential light construction
can someone direct me to a section in ubc97 that allows roof live load to be ignored when floor live load is considered in total load?  hence, roof live load does not have to be considered to act simultaneously with floor live load in residential light contruction.  ???

to the best of my knowledge, roof live always acts simultaneously with floor, except in seismic or wind combinations, when using alternate basic load combinations (sect. 1612.3.2). also,the ceiling live load of 10 psf does not act in conjunction with regular roof live load.
section 1612.2.1 gives load combination factors for lrfd, and section 1612.3.1 is basic load combinations for wsd.