Rerouting the bath drain

[Eigenvector]

My bath drain, drains very slowly. It doesn't appear to be clogged with hair and it drains into a septic tank. No other drain seems to have a problem. However I was wondering if the way the previous owner routed the drain lines might be the source of the issue.

Shows the drain. There are two obvious things that make me wonder. One, as you can see there is a wierd PVC joint right above the transition to the galvanized pipe - almost like they necked it down, you can see all the green joint compound. The other is the absolute horizontal pipe that runs from the tub drain to the PVC "T" junction. Could this be the source of my slow drain? I presume the vertical PVC pipe section is for the tub overflow drain - it doesn't go anywhere else and it isn't a vent so far as I can tell.

A couple of questions, if I were to snake the tub drain, would the trap cause problems Second, if I were to redesign the tub drain, how do I deal with the sewer? I presume that there is basically raw sewage all the way to the top of the tub drain "U" trap. Should I crack out the NBC suit and call in the EPA or are there alternatives to dealing with the sewer line?

BTW: I finally cleaned out the bulk of the spiders in that corner, as you can see its relatively clean now. The webs back there made the opening scenes of Raiders of the Lost Ark look like Martha Stewart dusting cobwebs.

[Paul Franklin]

The PVC stuff is just a standard tub setup. That wouldn't cause a slow drain unless it's clogged with soap scum and hair, which is pretty common. You are correct that the vertical leg goes to the overflow.

You can try snaking the drain with a small diameter spring snake down through the overflow. If you use the type that you can spin you should be able get it through the trap. If the tub has a trip-lever stopper on the overflow plate, it will pull out up through the overflow when you remove the plate.

If you can't snake it or it doesn't help, you are going to have to take it apart. IIWM, I'd cut the galvanized leg midway between the trap and the stack, and replace the trap with a pvc one with a cleanout. You can couple the PVC to the galvanized with a fernco coupling.

You may find the galvanized piping is so corroded inside that it is restricting the flow. If that's the case, you are in for a bigger job.

Good luck,

Paul

[Carpenter]

Just curious, how do you know that?

I would say no, the section past the P trap seems to slope well but I can't see what happens after that.

Yes, should be the overlow

Shouldn't but it's always better to be very gentle when snaking old pipes.

Another think you may want to check is if that drain has a dedicated vent pipe

and if that pipe is clogged. Birds, wasps, bees. etc have a passion for those vents.

Not sure what you mean here.

Actually no, that pipe should be empty when not draining water from the tub. Only the lower part of the trap should hold some grey water, but no sewage.

No, and no need to call the cavalry either. If you re-route the pipe (why?) or replace it, just stuck some rag on the septic side to keep the odor down until you'ready to reconnect. You don't want that rag to go all the way inside the pipe, right? No offense, but replacing that drainage pipe is a job is better left to a pro.

Now you have some very p...d off spiders there.

[Don Young]

There is nothing evident in that picture that appears unusual or that should cause a slow drain. You can snake thru the trap with any small snake.

Don Young

[Eigenvector]

Uhhhgg, I was hoping you wouldn't say that. Well actually it won't be so bad, the pipe doesn't run very far before it dumps into the main septic line.

Just out of curiousity, is the galvanized and PVC line gonna be full of septic water?

[Paul Franklin]

No. As another poster pointed out, the pipe will be empty except for a little old bath water in the bottom of the trap. (unless something is really, really wrong!)

Well, that's not quite true, it will probably have a pretty disgusting build-up of sludge, soap scum, hair, lint, etc. But no sewage or (ahem) waste. (Unless you have very unusual bath habits :-) )

Paul

[BobK207]

I presume that there is basically raw sewage all the way to the top of the tub drain "U" trap. Should I crack out the NBC suit and call in the EPA or are there alternatives to dealing with the sewer line?