Shower drain pipe with no slope - what to do?

[Xiaotian Guo]

Hi,
I just finished my guest room demolition for a gut remodel. After opened the damaged subfloor above standing shower, I found that the ABS drain pipe has no slope, I put a torpedo level on it and it's dead center
The level drain pipe(OD 2.5) is about 1 foot long between the P-Trap and sanitary tee. To replace it would significantly increase the scope of my project, I assume I will have to do the following to fix it:

- Cut the vent pipe above the bottom plate.
- Open the wall (another bathroom, tiled shower wall) downstairs. cut the section
- Remove the sanitary tee between the ceiling and floor, the drain pipe in question and p-trap
- Reconnect everything and make sure the slope is right.

I could ignore this and do nothing about it, but I am worried I will waste the opportunity to fix a major issue I have had with this bathroom - before the demo, since I moved to this house, the shower had a urine smell after the shower, if I stop using the shower for a while it would go away. There wasn't any clogging issue, just the smell after shower. I did some research and suspected it's either vent pipe clogged. or the drain opening has accumulated some very nasty gunk - and give off the smell when heated by warm water - the drain cover was glued on with epoxy so I could not open and clean it. But after I discovered the slope issue, I started to think that might have something to do with it.

I'd really appreciate any advice or suggestions.

 

[Jadnashua]

IF the trap is full, you should never get actual sewer gasses into the room from the drainage system. If the riser is long, crud can accumulate on the walls of the riser, and being above the water trap, can smell. Harder to clean if you can't take the grate off.

If I had to guess, the smells you experienced were probably from an improperly installed liner and/or clogged weep holes in the drain. This is if the shower pan was tiled...if not, this will not apply.

Plumbing code requires that the waterproofing (this is NOT the tile or grout) to be sloped. That means the liner, which is what is tested when a flood test is done, not after the tile is installed.

The lack of slope is more likely to let crud accumulate. It may never be a major problem, but it still should be fixed.

 

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[Xiaotian Guo]

@jadnashua thank you for your reply!

The shower had a fiber glass pan. and I will be using a pre-sloped foam pan from USG.

I will post a photo tomorrow to get some advice on how to fix it.

thanks again.