Hi All,

I'm rebuilding a 1920's bathroom from the floor joist and studs, the question I have is the 1 1/2" Tub Over Flow ties into the trap which then ties into a 3" stack with a 3x3x1-1/2" Sanitary Tee. Do I need to install a vent in for the tub if the trap is 12" away from the stack? Currently currently there is no toilet draining into the stack above the tub tie in but we may install a toilet above in the future. So basically my question is, do I have to vent the tub right now? If not will I in the future if I add a toilet to the same stack above above the tub? Thanks!

Hi All,

I'm rebuilding a 1920's bathroom from the floor joist and studs, the question I have is the 1 1/2" Tub Over Flow ties into the trap which then ties into a 3" stack with a 3x3x1-1/2" Sanitary Tee. Do I need to install a vent in for the tub if the trap is 12" away from the stack? Currently currently there is no toilet draining into the stack above the tub tie in but we may install a toilet above in the future. So basically my question is, do I have to vent the tub right now? If not will I in the future if I add a toilet to the same stack above above the tub? Thanks!
Yes and no. Yes if you're going to add a major fixture, (toilet) over it, and no if you're not planing to add the toilet. Cheers, Tom

Thanks for the reply Tom, I have a second scenario for you, since I am planning on adding (in the future) a second toilet above the existing tub/toilet on the same stack, I was wondering if I tied the tub drain into the first floor toilet waste line horizontal run prior to it tying into the stack, would a vent still be required for the tub or would it be considered wet vented at that location? Thanks for any help you can offer.

Thanks for the reply Tom, I have a second scenario for you, since I am planning on adding (in the future) a second toilet above the the existing tub/toilet on the same stack, I was wondering if I tied the tub drain into the the first floor toilet waste line horizontal run prior to it tying into the stack, would a vent still be required for the tub or would it be considered wet vented at that location? Thanks for any help you can offer.

You would still be discharging a major fixture past a unvented minor one. EVERY fixture that's trapped HAS to have a vent and your tub would be unvented. Regards, Tom

Gotcha, thanks for the quick response!