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 08:37 AM.
Reason: oops ... you guessed it .... more spelling errors
"" an ounce of perception -- a pound of obscure "