Rerouting a vent
I'm converting a tub to a shower stall. After I demolished the cast iron tub I discovered that the vent didn't go straight into the floor. About a foot off the floor, the vent angles off at 45 degrees into the floor to the drain. This was hidden by the tub front apron.
The vent is galvanized steel above the 45 and copper below. I want to cut the galvanized pipe above the 45, continue the vent straight into the floor and then continue it horizontally to the drain.
Can the vent be run horizontally (with a slope) to the drain? Or do I need to attach the vent with a 90 into the top of the drain run?