Does anyone ran into a defect analysis inspection for a villa where the occupants complain from a bad sewage odor coming in and out every few days? It is not continuous but rather comes and go. Any thoughts on what could be the root cause and what and how to inspect this?
Thanks in advance
Do they have any fixtures that they only use every few days?
I had a house where one of the showers trap probably wasn’t installed correctly because if we were gone for a few days we would get a little sewer gas smell but it would go away once we ran the water. Never had an issue when we were home with daily use.
Thanks, Tony. Possibly but I’m going tomorrow and will ask these questions. But why would the water in the P trap disappear so quickly though?
How many/where are S-traps installed, (other than the WC), eg. Island Sink with DW?
Does it have a proper Standpipe installed correctly?
Like others noted, dried out traps on seldom used drains, poor plumbing venting, i.e. sink or tub gurgling when toilet is flushed, sewer vent terminates in the attic and S-Traps siphoned dry. Definitely a plumbing issue.
Will check tomorrow. Thanks Jeffrey
Thanks Randy. All possible !
Seeing it is not a daily thing, I would look at the building pressure, referenced to the outdoors.
Dry Traps are easy to check, but when that doesn’t work, you need to find the source. An open trap facilitates sewer (or other smelly gas) to enter the building envelope, but it takes a negative differential pressure to allow it to enter the building. HVAC duct leaks are a primary. Wind direction and intensity is secondary, as well as Building Stack Effect.
You can have an open window in your house, but no air will come or go through it without a differential pressure. Focus on what causes the differential.
I went today and here are some facts that might give more insight:
- The smell always appearing in the Master bedroom/bathroom and it usually starts when they turn the AC on. Stays for 10 minutes then disappear.
- All water closets/fixtures are regularly used, so no dry traps
- The two sinks in the master bathroom doesn’t have P-Trap installed. It is a “Cup” style and the plumber that did the installation is arguing that they do not need a P-Trap as the floor drain has one?
- The vents pipes are extending well above roof surface and is way far from the exhaust fan pipe
Does this gives any new insight o what can this be? Could the vent pipes be leaking somewhere into the walls? Will a smoke test help confirm that?
Any help is appreciated.
I’ll also post the same in the “general inspection” section to expand the ideas.
Got a pic of this???
Also… did you observe any AAV’s, as they typically only last a few years and nobody ever replaces them because they don’t realize they go bad so quick.
A smoke test or the preferred peppermint oil test will confirm the proper installation of plumbing vents and trap seals.
Where is the pic of the “Cup style”? I’ve never heard of that before.
Looks more like a hair trap typically installed in a beauticians sink. Not exact, but close.
Yeap. And I’d be willing to bet that is the problem.
As I said, HVAC duct leaks pressure/depressurize the building if the leaks are outside of the conditioned space. A Micro-manometer will show you change when the HVAC is turned on. Smoke can also detect this if you know how…
Looks a bit like a drum trap. Do they also have clogging problems. I also like @dandersen approach because the issue starts when the AC fires up.
“The main problem with drum traps is that they’re not self-scouring. A drum trap holds so much water that the water and solids coming in to the trap will not be pulled directly through, which can allow for the accumulation of solids in the bottom of the trap. This makes drum traps more prone to getting clogged.”
The last pic above showing the sink drain