2nd Story Bathroom Venting

[Bob Hope]

Hi all,

I'm finishing a bathroom on the 2nd floor of my 1915 home. The previous owner added the rough-in plumbing and I was wondering if the vent will work properly.



I think I was mostly worried about the toilet pulling the p-traps but now i'm wondering how well the tub and sink will drain being behind the vent.

 

[Jadnashua]

I think the limit on 2" pipe is 5' from the vent. Note, you can combine vents to maintain the single one through the roof if they run up at least 42" or 6" above the flood plane before they run horizontally. Ideally, each fixture would be vented.

 

[Sponsor]

 

[Terry]

The vent should have been off the lav.

What you have isn't right.

 

[Bob Hope]

Can i make it right?

All the plumbing is in the floor of the 2nd story and the walls were drywalled when i took over. I'd rather not rip into those.

Should i look into adding air pullers at the lav and bath then leaving the roof vent for the toilet? Would that be better?

 

[hj]

The existing vent works for the tub and toilet, but if your lav is drawn properly, then it is NOT vented and has an "S" trap. Since it was a DIY installation by someone who may NOT have known how to do plumbing, I might also be concerned about if he revised the FIRST floor venting when he added the bathroom above it.

 

[Bob Hope]

So can i add a local vent under the lav and be ok then? I know it's not ideal, i just want the plumbing to function correctly

 

[hj]

How you do it would determine whether the plumbing works correctly, or not.

 

[Bob Hope]

So we filled the tub for the first time this weekend, and upon draining it, water started dripping in a door frame on the 1st floor. Looked like we got maybe 2-3 cups of water from draining 30 gallons out of the tub. I opened up the ceiling in the basement stairway to find the leak, but it won't leak again. Have you guys seen this type of activity before? Was it just accumulated condensation from the cold water lines (pex)? Condensation on the Sch40 from from draining hot water? I've had lots of condensation on the water lines in the basement the last few days with the warmer weather.

 

[Terry]

2-3 cups of water is a lot.

Did you fill the tub to the overflow?
Does water leak when you pull the diverter on the tub?

 

[Bob Hope]

We did not fill the tub to the overflow, it's a 72" x 36" x 22" deep and takes the whole volume of the water heater. I don't have a diverter installed yet, but I let the kids take a bath. During the draining process it started raining from the doorway. This door isn't directly below the tub, more like under the sink in the drawing above.

I suppose the kids could have splashed some water on the overflow, but there was no evidence of moisture when i looked in the access hole at the tub, or in my new access hole under the tub.

I had this happen a few years ago at my last house. That time it wasn't a fresh install though. That one did the same thing, dripped a bunch of water once during the drain cycle, and never again. I had access to the side of the tub through a half wall attic and there was lots of condensation on the copper.

2-3 cups is just an estimate, it may have only been 1/2 - 1 cup, looks like a lot more when it's raining inside the house. It wasn't a real volume type leak, more of a drip for 15 minutes or so and it continued after the tub was empty. I took that as just the water making it's way from the leak to the eventual output.

 

[Jadnashua]

While possible, this time of year, condensation usually isn't a big issue. Then, there has to be air movement to replenish moisture that might condense, and in a closed up wall, that shouldn't happen. Make sure the tub doesn't flex and leak when someone is standing near the drain. Then, ensure it is level and they didn't splash a lot of water up and it drained off the edges. If the overflow isn't installed properly, the gasket can easily leak, and children in the tub will likely make at least a few waves...

 

[Bob Hope]

I'll throw them back in there tonight and see if they can replicate the problem.

Thanks for the help so far.

 

[Bob Hope]

Put the kids in again last night, no leaks... What is going on here? I don't want to seal everything back up only to have a leak again. I'm thinking since the new plumbing access is above the basement stairs i'll just put a panel in rather than repair the drywall.