+ Reply to Thread
Results 1 to 6 of 6
  1. #1
    Join Date
    Sep 2008
    Posts
    1

    Angry foul odor backup

    My home is built on a slab as are most here in TX. My hall bathroom (sink, toilet, tub/shower) develops a foul odor like an open plumbing vent after about a week of non-use. I suspect a leak or evaporation in the trap but I can't get to it because it's burried in concrete. For now, when I notice the foul odor, I flush the toilet a few times and run water in the sink and tub. I also use "stick-ups" to cover up the stink.

    I'd like to know what might be the real problem and what I can do about it.

  2. #2
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: foul odor backup

    Yep ... that's a tough call.
    If this problem only happens after a week of non use of this bathroom you might be on to something.
    The only trap that would under the concrete slab would be for the tub.... it's unknown what the drain pipes are made of .... black ABS or white PVC or cast iron .... copper ?

    Would it be the water in that trap is evaporating ? ..... maybe .... perhaps there might also be a slight leak from either a hole in the trap or the connections are leaking. Either way .... it might be slight enough to allow the water in the trap to leak out over the course of a week of non use.
    Running water in the sink or flushing the toilet shouldn't have any effect on this trap though.

    Sure hate to have to break up the concrete needlessly ......maybe use the drain stop on the tub to try to isolate if this tub trap is the source.

    Just a guess.
    Last edited by canuk; 09-22-2008 at 07:37 AM. Reason: oops ... you guessed it .... more spelling errors
    "" an ounce of perception -- a pound of obscure "
    - Rush

  3. #3
    Join Date
    Aug 2007
    Posts
    1,131

    Default Re: foul odor backup


  4. #4
    Join Date
    Aug 2007
    Posts
    6,614

    Default Re: foul odor backup

    A week shouldn't be long enough for the water to evaporate out of any trap. I would suspect possibly a clogged vent stack, in which case the water would be sucked out of the unused bathroom traps every time the used bathroom (assuming at least two bathrooms in the home ) is occupied.
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

  5. #5
    Join Date
    Jan 2008
    Posts
    731

    Default Re: foul odor backup

    if you have an S trap on the sink replace it with a P trap. how old is your house? chance you have a drum trap on your tub?

  6. #6
    Join Date
    Jun 2007
    Location
    NH
    Posts
    4

    Default Re: foul odor backup

    Are you sure it's a smell coming from the drain system, and not one coming from the water supply? Do you smell it in the house before you run any water?

    Does it smell like rotten eggs? If so, it could be an excess of Hydrogen Sulfide vapors. That can be caused either by a diminished sacrificial rod in the water heater, or if you get your water from a well, there may be bacteria present. You can Google ways to deal with these.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •