Shower backing up problem

I have a 50's era home with a downstairs shower. We have never used it as the tile was cracked and falling off, but the bathroom would occasionally have water leaking on the floor. I finally realized that when the upstairs bathtub was full and drained it would overflow and come up the shower drain, which would then leak through the broken tile onto the floor. It only happened when the bath drained. Showers or just running the water wasn't enough to cause the overflow. Plumber snaked the pipes but that didn't help. He thought the pipes would likely need to be replaced, so now that we have decided to remodel the downstairs bath I got to work with the jackhammer. Here's what I found.



Vertical pipe on the left is the drain for the bathtub, vertical pipe on the right is auxillary vent.

Here's where the shower drains going the opposite direction as the previous pic.



Vertical pipe coming in from the right is the drain from the sink upstairs.

Here is another view of the pipes leading to the main stack.



Vertical pipe right next to the main stack is a vent (connects to the toilet drain in the floor). Main stack drains the toilet in the bath directly above. Both the sink in this bathroom and the one in the bathroom above drain via the vertical pipe on the far right. They both connect to the vent next to the main stack.

I had originally planned to just replace the pipe myself in its original layout, but now I'm wondering if the backflow is a design problem vs clogged up pipes. If that's true I'd rather hire a real plumber to redesign the system. How would you professionals tackle this? Is the drainage set up properly? Thanks for any advice and I can take more pics if you need clarification.

For Seattle, it's set up fine.
If it's not draining, it needs to be snaked and cleaned out. I like to throw some Bio-Clean in there too, to help with the goo that can accumulate in the pipes.
Or, since you have it all open, you could just install new pipe.
If the grade is fine, and the pipes are clean on the inside, it should have worked.

Terry said:

For Seattle, it's set up fine.
If it's not draining, it needs to be snaked and cleaned out. I like to throw some Bio-Clean in there too, to help with the goo that can accumulate in the pipes.
Or, since you have it all open, you could just install new pipe.
If the grade is fine, and the pipes are clean on the inside, it should have worked.

Click to expand...

Thanks for the reply Terry. Since I have it open I'll just replace as much pipe as possible now. Not sure why snaking didn't work but I'll test it thoroughly before closing back up again.

Sometimes extra effort with the snake is required or jetting. At this point with it all exposed if it was me I'd just replace it with PVC.
But I would have also 1st gone with a better cleaning effort and possibly a camera inspection before breaking all that concrete.

Pipes were too small for the camera so I was told. There were other issues with the concrete so I had to do some demolition anyway. At least now I'll feel better the pipes won't be the issue in the future.

That would depend on the camera used...

That's true, but he didn't have anything for 2 inch pipe. This was a fairly large reputable local company that I got a personal reference for, so I took it at face value. The basement is getting carved out for groundwater issues (that's a whole other issue), so it wasn't a huge stretch to dig up the piping too. Now I can at least take the plumbing out of the equation.

There are a few "large reputable" plumbing outfits in Seattle that don't have the personnel that are knowledgeable enough to give advice. That doesn't stop them from sending them out as experts though.

After the first attempt failed it was the time for a 2nd opinion. Not all plumbers are knowledgeable. The same is true for most professions. Some with basic knowledge, others that know their trade.

John