Strange sewer backup

[adwizard]

Hi. I'm new to the forum and am looking for some possible advice regarding an unusual plumbing problem I experienced a few days ago. I have a toilet and shower down in my finished basement. The other day my shower drain backed up. The unusual part of it is that my bathroom floor didn't get wet but the carpeting outside the bathroom shower got contaminated with sewer backup leaving me to wonder how the carpeting outside the shower area could get wet but not the bathroom floor itself. There is a 2" lip on my bathroom shower opening where you walk in to it. I can only assume the backup must have penetrated through bad grout or caulking when the water rose in the shower. In any event a plumber came out and roto rooted the main sewer drain to the street. He seemed to think that would take care of it. Yet I'm still wondering how an area outside the shower could get wet but not the bathroom floor. The plumber thought there might be a chance that the shower drain wasn't put in correctly or there is possibly a leak in the shower drain pipe itself, which would be an expensive repair. The pipe must run through the concrete floor of my basement. Any thoughts on this? The shower isn't used that often but when running the shower the other day, nothing unusual happened.

 

[Reach4]

The unusual part of it is that my bathroom floor didn't get wet but the carpeting outside the bathroom shower got contaminated with sewer backup

For most people, the area outside of the bathroom shower is the bathroom floor. Is this carpeting outside of the bathroom?

How far from the shower is the carpeting that got sewage on it?

 

[Sponsor]

 

[Smooky]

Maybe the carpet was laid over a floor drain.

 

[hj]

Maybe the water came out from under the toilet, which is the most likely.

 

[Jadnashua]

If it came from the shower, and did not come over the curb, the shower build is defective or has failed. Neither tile nor grout is the waterproofing in a shower...it is the decorative, wear layer. The shower pan should be water tight prior to the installation of any tile or grout. Unfortunately, a very large percentage of showers built in this country do not meet industry guidelines. They may look gorgeous, but while important, more important is what you can't see.

 

[adwizard]

For most people, the area outside of the bathroom shower is the bathroom floor. Is this carpeting outside of the bathroom?

How far from the shower is the carpeting that got sewage on it?

The bathroom floor is tiled. It's only outside the bathroom that there's carpeting. That carpeting is for the finished rec room and is immediately adjacent to the shower walls and bathroom walls (separated by drywall).

 

[Alternety]

If the toilet or shower are leaking, the water could be moving under your tile. That would explain wet outside, dry inside. Presuming the carpet is not covering some sort of drain or access port. I presume, since it is a basement installation, that the final impermeable layer would be the concrete floor.

Maybe pull the toilet and make sure the seal is in good condition. Put a new one on when you reinstall in any case.

Does the basement sewer line have a clear down slope to the main sewer? Is there a pump? Have you been dumping cheese?

If you are on septic, you could have a partially blocked drain to the tank or a tank that needs to be cleaned (or the sewer main if you are on public sewer). To really figure out where the problem is originating you really have to understand your overall waste water system. You problem is not that the water backed up; it is why it backed up.

 

[Jadnashua]

Common perception...concrete is waterproof. It doesn't get damaged by being wetted, but it does absorb and can pass some moisture through it, but it is not waterproof. Given it is thick enough, water may not go entirely through, but that's the reason why there should be a liner in the shower that is intact...neither the tile, grout, or setting bed are waterproof.

 

[Alternety]

I was not suggesting one should ignore the water characteristics of concrete with respect to properly installing a protective barrier. But he is trying to figure out where the water is coming from and how it gets to the rug. The permeability of concrete is not an issue in the short term problem being addressed. But it is a usable path to bring water from improperly installed things that can leak. Water from a leak can easily migrate under the tile if the tile was not properly installed. In the long term you don't want the concrete wet because of mold potential and the possibility of vapor diffusion making the room too humid and potentially destroying various floor coverings and things setting on the concrete. There are, of course, other possible issues such as a high water table, improper installation of roof drains, poor grading, and so on. But he is trying to resolve a single problem here.

 

[Cacher_Chick]

A leaking wax ring on the toilet is the most likely scenario if there is not a floor drain. If you really think the shower may be leaking, cap the drain and flood test the shower pan.