Smelly Hallway

[MichMich]

We had built this house mid 2023.
Since the beginning there was a faul smell, moldy-light sewage smell in the spot I’m picture from. We thought it was coming from the 0.5 bathroom (door on the right) but nothing there released smell. Not from toilet nor sink.
Doo ahead of us is laundry room. And there is no smell there.
And the one on the left is garage.
We’ve sealed (blue tapped) possible culprits and still it smells.

Almost like smell is coming from the walls? Is it possible?
We have 2 years warranty on plumbing. Plumbers came, did smoke test, no issue detected.

What do we do next…???

Thanks in advance for any tips and suggestions.

 

[Geofd]

Your picture only shows a hallway door show what you blue taped, I was going to suggest pest control co , but if it's consistent the pest would stop smelling
After a while

 

[breplum]

smoke test was smart. Your nose has to guide you.

Crawl space?

 

[havasu]

Since installing my outdoor shower, I never use my bathroom shower. I've learned it takes 2 weeks for my trap to run dry, and boy, does it get smelly. I wish I could add assistance, but this is way beyond me.

 

[Twowaxhack]

We had built this house mid 2023.
Since the beginning there was a faul smell, moldy-light sewage smell in the spot I’m picture from. We thought it was coming from the 0.5 bathroom (door on the right) but nothing there released smell. Not from toilet nor sink.
Doo ahead of us is laundry room. And there is no smell there.
And the one on the left is garage.
We’ve sealed (blue tapped) possible culprits and still it smells.

Almost like smell is coming from the walls? Is it possible?
We have 2 years warranty on plumbing. Plumbers came, did smoke test, no issue detected.

What do we do next…???

Thanks in advance for any tips and suggestions.

Have a plumber go up on the roof and pour 2-3 ounces of peppermint oil down each plumbing stack and chase it with a quart of warm water.

Have all hvac and fans turned off.

Do not let the man that poured the oil back in the house.

This will check if it’s sewage or not and may help you pinpoint the stank.

Might be the neighbor nasty wife ? I heard she stank

If this helps you then please donate $20.61 to your local cat lady to buy cat food.

 

[Aggie83]

I had a similar experience in my 2023-built house. Turned out it was coming from the attic where the AC is located. The AC tech installed the condensate drip line to discharge into a stack, with a p-trap. When the p-trap dried out, stinky! I'm near Abilene, Texas, so there's not a lot of time we don't have AC, but apparently takes about ten days of cold for it to dry out the p-trap.

We couldn't find it, so called the plumber. Plumber says he sees this frequently now and it is definitely not code. Made the AC contractor come out and install a line that exits outdoors.... Said they did it because people don't like the drip.... Well, I don't like the stink!