Sewer smell from shower on hot days

[Timmy1]

For about a year, my shower on a third floor is giving an on off gas smell sometimes after a shower and particularly in the morning not long after the sun rises enough to hit our roof.

I usually run some water into my p-trap and the smell goes away after a few minutes. There is a tub right next to the shower stall which we have tried keeping the plug in or out with minimal effect.

On advice of a plumbet, I climbed up on the roof and ran a hose with water to see if the water would backup anywhere in the 3 floors attached to thar plumbing stack. 2 kitchens and that upper floor bathroom showed no problems. He suggested running a 50 foot snake down the roof vent to see if some animal had been dropping stuff down the roof vent. I saw and felt a 45-90 degree elbow in the attick from on the roof with an 8 foot stick.

Particularly when the sun is hot the smell seems to come quicker in the morning. When its not a warm day the smell barely comes.

I cleaned the hair out of the tub drain. Couldn't get far down the shower. I have bleached both drains and in desperation ran drano through the abs shower drain as well. It seemed better a few days after the drano but has been back on and off a month now.

 

[Ben-gee]

You say ptrap, most shower drains rely on a cup and a dip tube to seal against smells.
Often the cup in missing - if yours is then simply replacing it should solve the problem.

But put some pictures of what you have and help may be forthcoming.

 

[westyrugby]

You say ptrap, most shower drains rely on a cup and a dip tube to seal against smells.
Often the cup in missing - if yours is then simply replacing it should solve the problem.

But put some pictures of what you have and help may be forthcoming.

Hi,
The shower itself does have a proper cup and dip shower trap but the smell still persists. I was asking how feasible it is to put some kind of trap on the external shower waste pipe as it comes out of the wall and before it enters the main drain pipe as I think the smell is coming from that.
Thanks

 

[Ben-gee]

That doesn’t make much sense to me from a plumbing point of view, but I might be missing something.
In answer to your question ; you can get a “running trap” to fit in-line in pipework, it is basically a U shape. But I don’t think this will do anything (however I appreciate you might be at the - may as well try stage)

Does the dip tube for your shower trap have an intact o-ring seal ? - this is a necessary part of these and if missing or damaged will result in smells.

 

[westyrugby]

That doesn’t make much sense to me from a plumbing point of view, but I might be missing something.
In answer to your question ; you can get a “running trap” to fit in-line in pipework, it is basically a U shape. But I don’t think this will do anything (however I appreciate you might be at the - may as well try stage)

Does the dip tube for your shower trap have an intact o-ring seal ? - this is a necessary part of these and if missing or damaged will result in smells.

Hi,
It does look intact but a little the worse for wear. I will get a new one and try that before the inline trap. Thanks for your help.