Dear group,

We moved into our fixer upper in September, since then I constantly smelled a sewer smell in the kitchen walls which back into a bathroom. All the sockets in the 3 connecting walls smell awfully. Several months of investigation, opening certain sections of the wall, my husband performed a smoke test, which pointed to a problem because we saw smoke coming out of one section. We opened up more of the wall, and discovered a nail sticking out of the vent pipe! This must have been there for 30+ years, when the house was first build. We called a plumber who fixed that. We performed another smoke test, and everything seemed to be fine. No gas coming out of any pipes/sections.
Now, it has been well over a week, with walls only now patched up, and the stench is just the same. Nothing better. It smells like we are in a public toilet. On top of that, the bathroom in the back of the kitchen also smells. Not as bad, but smells. We can't physically see if there is a P trap in the shower, so my husband filled it with water, and blocked it from draining. We left it like that for about a week. But the smell is still there despite being filled with water!
What are we to do? I am so frustrated and confused. What else can be causing the smell in both the kitchrn and bathroom? And can that smell be connected?
Can anyone advice please. Thank you!

common sources for sewer odors are from dry traps in floor drains, bad seals under toilets, and garbage disposals that are a wasteland of funky bacteria and food particles. I would suspect that it may be your kitchen drain itself, and not sewer gas, or there may be further problems that you simply didn't see in the smoke test. When it gets warmer, you may have to send someone up on the roof with peppermint oil to pour down the stack from the outside. You will know immediately whether there is a problem with the vent, or should. The other possibility that is nasty, but not uncommon, is that an animal or person may have used the furnace vents instead of the bathroom, and the smell is coming out of the vents themselves.

i agree 100% with my friend from MO. more testing is in order. peppermint oil mixed with warm water poured down a vent stack is where i would start.
the person who pours the oil can not come into the house for a while because they may smell of the oil and the test will be useless.

Thank you for the replies. I should have posted that the smell is coming directly from the the back of the fridge in the kitchen. That wall has the vent pipe which had the nail sticking out from it. The sink is about 5 feet to the left, and that whole section doesn't have the smell. There's no rodent in the walls either. Thr walls were opened and we checked with cameras. We are planning to check and reseal underneith the toilet, but wouldn't it smell more in the bathroom than kitchen? The kitchen smell is horrid. The bathroom smells much less.

Could this smell really just be the left overs from all the decades the sewer gas was coming in from the vent pipe with the nail in it?
Is there an exact way to check if there's a p trap in the shower if you can't actually see it?
Also, the walls in the kithcen have been sealed except for a plastic door which we haven't attached yet to cover some drain pipe. Can the peppermint/oil test be done with closed walls?

Thank you!



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you can shine a flashlight into the shower drain to look for standing water. that would be the water in the trap seal.
BTW, sewer smell in a house is sometimes very difficult to find.
there isn't another nail stuck into a vent somewnere, is there?

We didn't see any water when looking down the shower drain. But when we did the smoke test, no smoke came out from anywhere in that bathroom, including the shower. We were told the P trap could be slightly shifted.
If there was no P trap, wouldn't it start to smoke right away? Is it possible that there isn't a P trap, and it still not smoke for the smoke test?

Not to question the obvious, but you stated the smell is worst behind the refrigerator. Has the refrigerator been checked as the source of the odor?

Yes. The refrigerator is fine. The stench is only in that wall that's between the kitchen where the vent pipe is, and the back of the bathroom. The smell also travels to the neighboring attached walls, which we also opened. They have no pipes. But the smell comes out of the attached wall's sockets.



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if there were no trap for the shower, the smoke would definately come out the open pipe.

Would it be crazy to change the actual sheet rock and redo the walls? What if the smell permeated the actual walls over the last 30 years?

it would be dusty, but not crazy. I know several people that rip all the sheetrock out when they buy property (except closets) so they can inspect for hidden problems. At that time they upgrade any wiring that needs it, plumbing, and put in new insulation generally.

I think you can rule out the shower drain since you did plug it up and fill it with water with no smell issuing from it. The toilet definitely should come up and a new wax seal installed. Have you checked all the vents in the attic?

We have checked the vents in the attic.. All looks ok there. We resealed the bathroom tonight. Husband took out a few hihats in the kitchen, and the smell was just aweful (throughout kitchen and the neighboring corridor.)
Interestingly, he stuck his flex camera in all the openings in the ceiling, and the opening behind the fridge, which is next to the back of the bathroom had old mouse droppings. We definately do not have mice currently. Never heard or seen any in 6 months living here. Could something that is potentialy many years old be still giving off a smell that is so strong ?



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The odor would be 'current', i.e. not from months old mouse droppings. Are you familiar with the odor of a deceased rodent in the walls? If not, have you 100% ruled this out as a possibility?

A dead rodent wouldn't make it smell for that long, but a larger critter might....cat, possum, raccoon. A friend and his wife closed on their new house. The day they walked into the house, it was like a scene from a horror film. There was swarms of flies everywhere.It turned out a mother raccoon had given birth on top of the closed fireplace damper, and one of the babies had died.