Bathtub oddities

[djqfr]

Okay, where to start...

I bought an old manufactured home back in 1999. The owner declared there was some problems with rot around the bathroom and it was repaired. (It wasn't, but that's another story...)

The bathroom had rotted again, so I removed the rotten wall completely and replaced it.

However, the previous owner did something weird to the bathtub: instead of using the original drain in the subfloor, he removed it! He then lifted the tub nearly 6" and attached a trap to what I believe goes over to the bathroom sink (the vent.) The tub took forever to drain, so I decided to put it back on the floor where it belongs.

I routed plumbing in the floor back to the main pipe that exits the building. I installed a new trap and proper overflow set (old tub didn't even have that.) I had looked online for how to address the new plumbing issue re: the existing vent, but the only detailed site I could find didn't have a vent on this pipe.

Now I have sewer gases coming up (I am honestly not sure if it's from the bathtub, I can't really tell.) However, the bathtub goes into a T in the main drain right before the toilet - I am assuming now that I didn't use this original vent line that the toilet is sucking up the water from the bathroom trap every time I flush it.

I pulled the toilet back off & plugged the hole with a rag, and ran some water down the tub and so far haven't noticed a difference. The bathroom fan has been going nonstop.

I'm assuming that I need to snake that vent pipe around the floor joist and attach it to the new bathtub drain before it goes into the main drain, does this sound correct?

 

[Cass]

There must be a vent on the tub drain between the tub trap and T if there is no vent above the T.

All traps must be vented.

With out the vent you are right about the trap being sucked dry.

Is the old vent open / not attatched and allowing sewer gas into the room?

 

[Sponsor]

 

[hj]

drain

Without being there we have absolutely no idea how the tub is connected, why you are getting sewer gas, or how to correct it. Your description makes sense to you, but it leaves too much room for interpretation for us.

 

[djqfr]

Well, I pulled up the tub and ran the existing vent line around to the drain line after the trap. The only problem is the vent is about 2" lower than the pipe the trap is on. There is no room in the floor to T it from that existing height, it would hit the flooring and have nowhere to go. When the tub is full it does gurgle slightly while draining, but it's 90% less gurgling than what it was before. Also, when I flush the toilet and use other fixtures I don't hear anything from the tub drain. I think I'm safe now.

The tub while full takes about 3 minutes to drain, which is a heck of a lot faster than before. Before I moved the plumbing it would take almost an hour to drain, so only the shower was used.

I've also noticed the smell is now going away. The toilet must have been sucking the water out of the trap.

I guess this is what happens when you have 2 different people working on plumbing that don't have a complete understanding of what's going on.

Thanks for the replies.

 

[Jadnashua]

If I understand you, your vent isn't really acting as a vent and will accumulate crud. The vent can't be below the trap, since water flows downhill, it is trying to run out the vent line. Since it must eventually turn up, the water can't go any further. That accumulation of stagnent water will backflush a little, and may be a source of the smells you have.

 

[djqfr]

Oh, that's not what I meant. The line drops 2" and the T is pointing upwards, and that's where the vent is attached. It can't drain down the vent.

 

[djqfr]

I don't have the strong sewer gas smell any longer, but I do still have a smell. It actually smells somewhat like the cement used to glue the fitting together.

Does anyone know how long it takes for that cement to cure? I did the fittings yesterday and I still have a smell in the bathroom.

Edit: The reason I suspect the cement is because I got some of it on my hands and it smells similarly...