Broken Sewer Trap- Strong Smell - stumped plumbers - please help!

[HereComesJoe]

Hello all!
I’d greatly appreciate any help and advice from this forum.

The problem occurred after a routine router rooter clean out. Every couple years my basement will back up and due to roots and such clogging the pipe. This is usually remedied quickly with a snake. The clean out is usually done in the basement but can sometimes be done from the street.

After my most recent clean out I have experienced strong sewer smells. I noticed that the sewer trap no longer holds water. For reference, The top of the trap just sticks out from the floor and the rest is in the concrete.

In an attempt to eliminate the smell the plumbers cemented pvc on top of both the trap and an access that is further on down into the house. They then installed screw on caps.

The smell is still strong and when the heat kicks on it comes up through the vents.

The plumbers have been back and suggested running all the plumbing overhead. Thus eliminating everything in the floor. This causes a problem however Bc my basement relies on a trough drainage system with no sump pump. Eliminating the floor drainage would cause heavy backups with no source for water removal.

My question is, if there is a smell coming up from the the broken trap, would a pvc cap be enough to stop it from escaping?
Could the problem be solved by replacing the trap?
If not how might I figure out where this smell is escaping?
Thanks to everyone in advanced!
Joe

 

[Twowaxhack]

If the trap was broken and now you’re getting a sewer smell then I’d repair that trap.

it’s that simple.

 

[Jeff Handy]

Post pictures of what they did.

Hire new plumbers, these guys sound like chuckleheads.

 

[Jeff Handy]

Where do you live, how old is the house?
More info, the better.

 

[HereComesJoe]

Where do you live, how old is the house?
More info, the better.

Thanks to all for the replies. The house was built in 1888, located in western NY. I’ve attached photos of the trap access as well as the other access point.

As far as twowax said... that was my thought... replace the trap. But they seemed to think capping it would keep the smell out.
I attached a 3rd photo of the other side of the basement that has another drain... here the trap does hold water and doesn’t seem to be the culprit of the smell.

 

[Twowaxhack]

You likely have an open pipe or a fixture that isn’t trapped......perhaps a toilet with a bad wax seal......

Since your house trap is no longer protecting you, you’re getting stink from the city main.

just a theory......I’m in Alabama what do I know....

 

[Jeff Handy]

First thoughts are that the sewer line is leaking, and pooling sewage under your slab.
The old basement floor from 133 years ago might have been plain dirt.
Some homeowners would eventually pour a very thin concrete slab, called a “rat slab”, to keep out critters and bugs and casual ground water.
Sewer stink can still make its way up through thin concrete.
Just a theory.

 

[Twowaxhack]

First thoughts are that the sewer line is leaking, and pooling sewage under your slab.
The old basement floor from 133 years ago might have been plain dirt.
Some homeowners would eventually pour a very thin concrete slab, called a “rat slab”, to keep out critters and bugs and casual ground water.
Sewer stink can still make its way up through thin concrete.
Just a theory.

Sure it’s leaking. It’s not holding water any longer. It needs to be replaced or removed, not ignored.

 

[Jeff Handy]

Where does the trough drain dump its water?
There has to be an open drain somewhere for that, right?
A connection into the sewer.
Maybe that is the source of stink.

 

[johnjh2o]

A cast-iron house trap that was installed 133 years ago has failed. The bottom of the trap more than likely has rotted out. If was snaked often my guess is the snake has punched a hole in the bottom of the trap.

 

[HereComesJoe]

thank you all for the reply’s.
Just to update. The plumbers ran a camera through to find a broken pipe at the bottom of a toilet stack that was added to the house in the 50s. Although there was still flow, this hole creates a cess pool of sorts. This was almost undetectable without the camera.
We are going to rerout the toilet stack and dig up and replace the broken trap... and hopefully between the two repairs we will be rid ofthe stink.

 

[Jeff Handy]

I think you can eliminate the old house traps, they just cause trouble.
Just change to straight drain pipe, or maybe add a cleanout there.
Just my amateur advice.