How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Lindie Your Own Question
Lindie, Handywoman
Category: Home Improvement
Satisfied Customers: 5490
Experience:  Remodeling & fixing things from Drywall, Flooring, Electrical, appliances for 20 years
Type Your Home Improvement Question Here...
Lindie is online now
A new question is answered every 9 seconds


Customer Question

We installed a bathtub in a bathroom that had only a sink and toilet. We tied into the sewer line, but did not run an additional vent, the toilet and sink were both vented and the tub ties in beyond those vents. On 90 degree plus days, the smell of sewer gas is overwhelming (no smell at all other times). We tore out a wall and ran a vent, but it still smells. We have no idea why we have sewer gas smell in that bathroom. It never stunk before we added the tub and the smell only comes out of the tub drain.
Submitted: 11 years ago.
Category: Home Improvement
Expert:  Lindie replied 11 years ago.


When you installed your drain for the tub did you install a S trap? Here is a link that will give you an idea of what I am talking about.

Customer: replied 11 years ago.
Reply to Lindie's Post: Not sure, I have to call my husband and see if he did that or not. I saw some references on another website that talked about a p trap but I haven't seen anything that talks about an S tap. I'm trying to find out the difference. Thanks for the link
Expert:  Lindie replied 11 years ago.

Depending on how your pipes are connected under the house will determine if you can use a S or a P. Here is a link I found that shows a P trap. The pic of this is on the bottom right hand side.

Both S & P do the same thing as far as keeping some water in the drain which won't let gases back through. It depends how your plumbing situation is, We used an S-trap right below our drain. And ran a straight pipe to the main drain. (at an incline)

Now in our other bathroom we have a P-trap due to space and what worked there to the main drain.

If you look at both links I sent you can see what the difference is on both the S & P traps. Hopefully you have one or the other. But if you have the gases coming back up, it sounds like you don't have one or if you do, the seal was broken.

let me know if you need anything else. Isn't remodeling fun? I just remodeled our playroom/family room. Just trim is left then time for carpet people to come in and lay that down. Only 2 more rooms left to do.. hip hip hurray!

Lindie, Handywoman
Category: Home Improvement
Satisfied Customers: 5490
Experience: Remodeling & fixing things from Drywall, Flooring, Electrical, appliances for 20 years
Lindie and 2 other Home Improvement Specialists are ready to help you
Expert:  Marty replied 11 years ago.

My bet is that you do NOT have a trap !! Follow the drain pipe of the
tub... At the top you will will have a "trip lever/ overflow " , this
lets the water drain out or stay in the tub,it also allows water to run
out in case of over-filling.... Follow this down.... You should come to
a "T", where the tub drain meets the trip lever/ overflow pipe.... just
below this, you should find a "U" shaped pipe.... this is the "trap" it
prevents sewer gas from entering the house. If this is not present,
then this is your problem... NO TRAP !You will need to add one. As an
aside, Are you on sewer or septic ??

Customer: replied 11 years ago.
Reply to Marty's Post: Hi! I have accepted and paid the first responder to my question, she was correct, we did have a P trap, but in my husband's haste to get out of the stinky, dark, crawl space, he actually installed it sideways on accident, which didn't "trap" anything. It is now fixed and my bathroom smells great (well, it smells as good as you might expect a bathroom to smell). Thanks for your help.
Expert:  Marty replied 11 years ago.


You are most sincerely welcome !!

Thank-you for the response.... we don't often get to hear the final outcome!