I'm roughing in a bathroom in the basement. How high should the vent line be for the fixtures. (vent line in the wall)

speedball1

Are you asking how high that stub-out coming off the vent should be? For the lavatory stub out at 18" from floor to the center of a 2 X 2 X1 1/2" sanitary tee. Toilet roughs at 12" to the center off the unfinished wall and the tub roughs in at 15 1/2" off the unfinished wall at the side and 1 1/2" to the center of the traps raiser off the front plate. good luck, Tom

iamgrowler

At least six inches above the flood rim of the fixture being served before going horizontal.

42" is a standard height for horizontal vents.