Sewer smell

mattmia2

There are access panels that are designed to go in the hole you cut. I'd go with one of those. but i would actually just feel with a snake if it goes in to a bend in the wall, there is no reason to access the outside of it, you can clean it from the standpipe if there is a trap in the wall like there is supposed to be.

JUGHNE

It is possible that the vent pipe may have pulled out of the top of the drain tee.

Stranger things have happened.

I was about to rebuild some fittings under a laundry sink when our house was new, and found out that they were only dry fitted together. Didn't leak that much either.

Yes, again IIRC, that is the only PVC leak I'd ever had....

BTW, is the sump vented or just open top?

SlamDunk

It is a covered sump.just a hole in the floor.

Best that I can tell, there isnt a trap behind the wall, so im going to install one where i can see it for the heck of it. Thanks everyone.

Alan (California Radiant) Forbes

What you're suggesting is not a viable solution. The trap you want to add is not vented and the water seal could easily be sucked out.

If that "vent" is a drain, just add a tee, trap and vent valve.



If it is truly a vent, it's even easier.



Jamie suggested these solutions yesterday.

SlamDunk

i may have miscommunicated.  my drain system is well vented.   Here is a rough draft.  
l will add an air valve as well.  if there is a trap in the wall, clearly it is drying up between washes.     wm=wash machine.   hope this clears it up.  

JUGHNE

Also, even if the plumbing for the DWV is perfect, if the vent riser is plugged from some back up or critter inside then there is no venting.

Then sometimes the trap can get syphoned almost dry to pass gas.

Take a garden hose onto the roof and run water down the vent, it should take all the water you could give it. If up there you could flush all the VTR's.

SlamDunk

oh, now that is very possible!  

Intplm.

SlamDunk said:

line is not trapped.    But they did give me two clean out tees.   

Hey there @slam dunk
From this picture.....yes, look below the laundry box. When you open the wall there should be a 2" -P- trap just below the box at about 18" down. There should be a vent line extending just above the trap piped with a "TY"
Is the smell greatest at the box? If no trap then the problem is solved by adding a -P- trap with a proper vent.
Take a pic and post it here to have a look.

mattmia2

Or just look down the standpipe to see if you see water and stick something rigid down it to see if it turns in to a j bend somewhere in the wall.

Mad Dog_2

Mad Dog_2

Once the caulking separates, they are going to get a smell of Methane sewer gas.  Illegal joint.  Mad Dog 🐕 

Mad Dog_2

Atleast the G.C. knew enough to vent it..stack vent, wet vent, better than no vent!  Mad Dog 🐕 🤣 

SlamDunk

looks like Im back to square one.   the odor came back last night, at 8:30pm -again, with only dishwasher running.   stuck my nose in wash machine drain…clean, no odor so trap must be present inside wall.   odor was more powerful in basement/crawlspace.
   Soooo….tonite, i will inspect every inch of waste line that I can see with my eyes, feel with my hands, using both methane and H2S detectors. 

It is possible that the dw is sucking kitchen trap dry for some reason but it doesnt explain the smell in crawlspace.   Or the long spans between events.   I’ll post any findings when I find them.    

i hate sewer ghosts.  

SlamDunk

FOUND IT!!! @Alan (California Radiant) Forbes correction, @Mad Dog nailed it! I didn't scroll up enough.



In wall, reachable. I suspect stress from vibrations when new plywood/new roof was installed. This crack and abandoned drain line did not look like this one and a half years ago. I thank EVERYONE who helped me troubleshoot.

Mad Dog_2

Rotted pipe right?  Usual culprit ..looks like a trap arm for an abandoned Sink?    Old Galvanized?  Mad Dog 🐕 

SlamDunk

Mad Dog_2 said:

Rotted pipe right?  Usual culprit ..looks like a trap arm for an abandoned Sink?    Old Galvanized?  Mad Dog 🐕 

Yup! I abandoned that trap arm in place and capped the end of it. It was chronicly clogged and it didnt look like thatthe last time I saw it! I think with the hammering on roof, around vent, caused the corroded bottom to fall out. The timeline works.

Mad Dog_2

Victory!  Mad Dog 🐕 

PC7060

@SlamDunk - nice work. That’s exactly the situation I had with the cracked CI. It’s the low pressure zones that pull the gasses out so you only get the smells periodically. 

SlamDunk

I have been thinking about that.   in the past year, we experienced the smell just three times at 8:30 pm.   I imagine many homes in this neighborhood do not have traps on main line so odors from street have to push into house main and up house vents.  some mornings, on the way to work, I can smell it in the air-outside.    

I guess 8:30pm is a prime time bathroom break in this neighborhood.  

Anyway, jb weld and flex seal saved the day.  when the weather cools a bit, I’ll drop a flex cam down the vent fro roof to see if there is more damage.     there is only six ft of it that i cant see.   

Alan (California Radiant) Forbes

FOUND IT!!! @Alan (California Radiant) Forbes correction, @Mad Dog nailed it! I didn't scroll up enough.

I'll have to change my tag line back to "Often wrong, never in doubt.".

JUGHNE

As a temp band aid you could drop a 4" test ball down the VTR.
I extended the air line with 1/4" copper on one and with a long rope could drop it down a long ways.

Then air it up to plug the CI.

That would prove that this is the only source of gas attack.

SlamDunk

Thanks everyone! Not the problem I wanted to find; I was hoping against hope it would be a missing trap. That would have been a lot easier to deal with. I have a good visual of remainder of stack from the attic down the chase. Just got to wait until the heat index is below 110.

SlamDunk

Alan (California Radiant) Forbes said:

FOUND IT!!! @Alan (California Radiant) Forbes correction, @Mad Dog nailed it! I didn't scroll up enough.

I'll have to change my tag line back to "Often wrong, never in doubt.".

@Alan (California Radiant) Forbes You were right, just not first! And thank God my pipes didnt look like your photo!

PC7060

@Alan (California Radiant) Forbes - haha, don’t feel bad.  I was a distant 3rd with the suggestion of cracked pipe. Quick fingers @Mad Dog_2 was ahead of you by a length and me by a furlong!

The cracked CI must be a common issue. @SlamDunk - was that CI a vertical or horizontal run?

 

Jon_blaney

Does it smell when the washer has been used for a fee loads. I could be the washer it self, not the drain system. This is a common problem.

I bet the trap on the drain is hidden in the wall.

SlamDunk

Vertical @PC7060, I suspect roofers hammering around roof protrusion may have caused stress to the pipe.

@Jon_blaney It wasn't washer itself, I had one of those once. the only common factor I had was the smell occurred around 8:30pm and we sit near the washer. But the third time I smelled it, I raced to washer, pulled hose but smelled nothing there, so, trap must be in wall.