I have a persistent slow shower drain which I have plunged and used chemicals on. The last plumber I had out here told me that it has a type of trap that cannot be snaked (opening is too small) and since it is embedded in the shower pan, it cannot be replaced without ripping out the whole pan. The drain does not fill up immediately when I turn the shower on but takes about 15 seconds to come up level to the floor of the shower. When I plunge the drain, water rushes in to the bottom of the trap then comes back up. I have just fished out 2 rusted nails that were at the bottom of the trap for some odd reason. When the drain finally finishes draining, I hear (if I am listening carefully) very faint glug glug but only when the water has basically finished draining. Oddly, the shower pipes are not connected to the sink or toilet but goes directly into the stack with a vent going through the roof (according to the plumber who looked in the access panel). Could this be a vent problem or should I just dump more drain cleaners in as the plumber told me to do even though I am having limited success with that.

The trap can be snaked. You may need to get a more experienced plumber to help you with the drain.

if the vent is available in the access panel, cut it and snake from there.
just use a sheilded stainless clamp to put it back together.

IT would only be a vent problem if you also had a clogged drain, so that is not a factor. Chemicals do NOTHING, except go down the drain. There is no such thing as a "drain opening too small to snake the line", IF the plumber is competent and knows what he is doing. Get a better plumber.

Thanks so much for all the replies. The trap is probably 50ish years old. It's not a regular p trap. It looks like a short cylinder with a flat bottom and looks like it folds up onto itself and it's all in one piece. I tried to get a "zip it" tool in there and I couldn't even find the opening where the drain goes.

As to trying to access from the vent, my situation is a bit sticky as all the wires from my electrical panel go from the panel under the shower pan along the plumbing. The plumber didn't want to get anywhere near the wires with a flame. And he said that someone had cut the pipe at the Y where the vent meets the drain then epoxied it back together probably because he couldn't use the soldering kit in that situation.

Hence, I was hoping it could be the vent that I can access from the roof but maybe I need a plumber to cut through that Y connection again.

quote; but maybe I need a plumber to cut through that Y connection again.

I am glad you said "might", because a good plumber may not have to do it.

It sounds like you have a drum trap or some other style of trap that can't be snaked correctly; Yes, they can be cabled, but not properly. Hj's suggestion of cutting the vent and running up the line backwards is a good one, and works well with a Tee connection, but not with a Wye. If your electrical is that much of a mess, you should consider getting an electrician to clean it up. It may not be cheap, but professional electricians don't run wires along the plumbing in the first place, and you may have a dangerous setup. At some point, that drain will most likely have to be removed because the epoxy won't last. The shrink and swell of the metal with temperature differences will eventually cause the joint to fail, and someone is going to have to get in there to replace it. You would be better off having someone competent in there to remove that old trap and put a p-trap back in its place. If someone is careful, they shouldn't have to destroy the old drain assembly to get the pipe off in the first place. Careful cutting with a dremel tool cutoff wheel can usually get old fittings off if nothing else works.

Sounds like an old barrel type grease/waste trap.
Best Wishes

I was quite surprised when the access panel was removed and I saw what was there. Really not a good design.

OK. So it sounds like it is unlikely the vent being blocked and is instead some sort of stoppage in the drain line which has to be snaked.

That is what it sounds like to me. It is most likely a hair clog between the outgoing side of the trap and the drain stack.

THEORETICALLY, but good luck, you can unscrew the top of the trap for access


when you are prepared for a total fix you can try it, but, be prepared to replace said trap

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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Have you EVER seen a drum trap used for a shower?

yes.. i have also seen a drum trap used to catch both a shower and a lav.
i fact i think i remember (years ago) in boston seeing a tub, lav and kitchen all sharing an octopus style drum trap..
it may have been 3 in, 1 out and a vent off the top?? lead of course..

Thanks again. I looked up drum traps and one mine looks like "zurn drum trap and shower drain" and it does look like it is embedded in the floor of the shower -- what looks like concrete. It does not have a clean out that I could see. We only have access from the bottom of the shower. I am discouraged but I will see if I can get another plumber's opinion but as I said before it's already jury-rigged with the epoxy at the y connection to the stack and I don't want an even crazier situation on my hands.

Happy Thanksgiving.

Are the lines lead or cast/galvanized?

The plumber said the trap was iron. All my pipes are copper and I believe the stack is cast iron tho the plumber didn't say anything about what the stack is made of.

If the trap looks like this: then it should be able to be cabled out. If it looks like: or then I wouldn't touch it. The lower left picture has very tight bends that wouldn't allow a proper cleaning, the lower right allows the snake to tie itself into a knot in the trap. While I don't endorse the practice, I have seen people cut an access hole in the top of the pipe to snake it out, then tape it back shut. It isn't a good practice, and in any situation that a leak could cause damage, it isn't a safe one simply because of the chance of water damage. I still stand by the fact that you need an electrician and a competent licensed plumber to rectify the situation.

quote; I have seen people cut an access hole in the top of the pipe to snake it out, then tape it back shut.

I have done it when it was impossible to snake the line properly, usually because of an improper back to back installation. I either insert an expansion "freeze plug" or put a repair clamp over the hole to seal it.