What if the vanity has it's own vent out the roof?
What if the vanity has it's own vent out the roof?6" above the tub, but you also have a vanity in the room so i would make any vent intersection 6" above that- the highest fixture served. Typical height is 42"
Got....thanksTrue. Nothing will change that. But as long as the vents are tied in properly, no water will find it's way into any horizontal vents while the bottom floor floods.