1

In our very old stone farmhouse, there is a wetroom downstairs with a shower drain. Ever since having the septic tank emptied, and then replaced with a treatment plant, a foul stench comes from the shower drain.

There is no smell from the toilet and sink in the same wetroom.

There is an obvious escape pipe up the front of the house which serves the kitchen sink and upstairs bathroom, none of which smell.

I can't see any obvious escape pipe for the wetroom in the back. But it's strange that the sink and toilet don't smell, only the shower. All the pipes go out the front to the septic drain, so I guess the wetroom is connected at a distance to the front escape pipe.

Is it possible to deduce anything from the picture of the shower drain or general knowledge about a possible cause for this (including the escape pipe answer)? It would be great to get rid of this smell without having to replumb the entire room, but I can accept that too if I have to!

enter image description here

Improve this question
2
  • Is there a crawlspace or basement underneath that room which would allow you to look at the drain plumbing?
    – brhans
    Commented Aug 5 at 13:13
  • Unfortunately not. It's a stone farmhouse built on stone next to a quarry. I'm thinking maybe the original plumber didn't want to/couldn't dig down far enough, wishing he had though.
    – SingularityFuture
    Commented Aug 5 at 21:27

2 Answers 2

Reset to default
2

As other answers have indicated, this drain likely does not have a P trap. There are several low-profile and tight quarters options for P traps, and depending on your location and code requirements, you could have several options.

  • Bottle trap - more common in Europe than North America, shower drain bottle traps can be very low profile and only slightly larger in diameter than the shower drain. This might not require excavation. shower bottle trap
  • low profile P trap - there are different types, some with very tight turns or flat tubing instead of round. low profile shower trap
  • in line trap - these are often banned by local regulation or building code, but if the plumbing is laid in solid stone and you don't have a local regulation, then placing an in line trap somewhere after the shower drain in the waste line but before it joins to a soil line or the main sewer line will stop sewer gas from venting into your shower. in line trap

The different traps may work better or worse for your situation, depending on how or if your plumbing lines are vented, their size, and their slope.

Improve this answer
1
  • Amazing! I didn't realize there was one that goes in the drain itself. That could save us a lot of heartache and money!
    – SingularityFuture
    Commented Aug 13 at 8:08
2

Sink and toilet have something called p-trap, which prevents smells, your shower does not seem to have one.

Improve this answer
2
  • 2
    Or you have get the trap run dry. Or there is a vent stack problem and the trap is not quite sufficient to block the higher-than-expected gas pressure, in which case the fix is to make sure the vent is clear
    – keshlam
    Commented Aug 4 at 16:05
  • Thanks both. I'm trying boiling water and bleach first every day and seeing if that helps. Eventually we'll redo the bathroom and then we can make sure there is a p-trap in there. I think it's not there at all because you can actually hear the treatment plant running through the pipe.
    – SingularityFuture
    Commented Aug 5 at 14:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.