Please help! Lingering sewer smell in house

[Clairelucky]

Hi, In our recently bought house, there is open laundry area in basement. There is a standpipe for washer. Then we smell sewer ordor around the area. we called a plumber, He flushed the stand pipe with water and said the p trap is okay because there is water in it. But somehow, I can still smell the ordor from the pipe. He suggested installing an air vent, but he cannot guarantee that it will work. We tried to seal the pipe, but still there is smell. Now I am confused whether the smell is coming from. I am posting a picture here. Would you please see whether the standpipe is set up correctly, will the air vent solve the problem? Thank you very much ! I am really frustrated with the smell.

 

[Terry]

Normally you would have a vent on the p-trap and standpipe. And yes, it's not plumbed right.

Sometimes the smell in the walls or flooring.
Zerolac can be used to paint over wood that has an odor to seal it off.

 

[Sponsor]

 

[Dj2]

Who ever plumbed it "forgot" to vent it...

 

[Jadnashua]

Over time, a standpipe might end up with a coating of soap scum - the water generally moves fast enough to scour the pipe fairly clean, but maybe not always. A long bottle brush and some elbow grease might clean it up, but otherwise, if the trap is not getting sucked dry or siphoning, that's not the problem. When it smells, use a flashlight and verify that there's still water in the trap. It might just take certain things happening to suck it dry, and when the plumber looked, it was fine, but it might not stay that way all of the time.

Do you have a floor drain somewhere? If those do not have a trap primer, they'll dry out and can be a source of sewer gasses.

 

[MACODEDOC]

WELL LETS LOOK AT BASIC PLUMBING, WHEN WATER IS DISCHARGED YOU CREATE A NEGATIVE PRESSURE IN THE PIPING. IF YOU DO NOT HAVE PROPER VENTING YOU ARE SUBJECT TO A VACUUM AND TRAP SEAL LOSS. TRAPS ARE DESIGNED FOR A PLUS OR MINUS 1", THIS IS THE ONE THING WE OVER LOOK, WINDY AREAS CAN MAKE THE TRAP SEALS JUMP AND EVENTUALLY LOOSE A SEAL. WITH THAT SAID THE TRAP IS NOT VENTED OBVIOUSLY AND WITH THE HOUSE DISCHARGING AT THAT CONNECTION POINT THE MOMENTUM COULD DRAW THE SEAL AWAY FROM THAT STAND PIPE OR ANY TRAP IN YOUR HOUSE FOR THAT MATTER.

WATCH THIS VIDEO

 

[Clairelucky]

thank you guys all! It's very very helpful. I will get a vent installed, hope it will fix the problem.