Latest Discussions : Plumbing


08:25AM | 09/26/06
Member Since: 11/20/05
7 lifetime posts
Sewer Smell:

I have a two story slab on grade house in Dallas Texas. The downstairs powder room has a single toilet and single pedestal sink. We live in an area with very active soils. This year we had an extreme drought and right after the first major rain I noticed a sewer gas smell in the downstairs’ powder room. The timing with the rain might be coincidence. We first replaced the toilet and wax ring... the old wax ring had gone bad and the previous toilet was rocking. We replaced the toilet itself for aesthetic reasons. I thought this would eliminate the problem. The new toilet does not rock, has a new wax ring, but the smell persists.

The powder room toilet and sink each have an individual vent stack. There is a bathroom above the little first floor powder room on the second floor. It does not align directly on top of the lower bathroom and therefore has it's own vent stacks that penetrate the roof at a different location. The waste drain lines from the upstairs bathroom do share a common wall with the downstairs powder room sink.

I called in a plumber who tried to perform a smoke test. The whole house clean out is just outside the downstairs powder room on its outside wall. The problem we encountered was that the pressure the plumber put on the lines pulled the water from the toilets into the pipe. Therefore the smoke that did enter the lines just entered into the bathrooms through the toilet bowl. He tried the smoke test a number of times unsuccessfully. He then ran a camera through the lines. (Both upstairs' bathroom vents and downstairs vents & under the slab in the small bathroom). He didn't find any obvious flaws except for a nail in the downstairs’ powder room vent stack. We opened the wall and repaired the vent, however the smell came back the next day.

The smell seems to be worst in the mornings and evenings... and I am beginning to suspect that the problem might have to do with the downstairs powder room sink or upstairs bathroom.

The plumber’s first visit cost me over $800... and we have not eliminated the problem.

What should my next step be?


10:52AM | 09/26/06
Member Since: 11/20/05
7 lifetime posts
Can you explain what a peppermint test is and how it is performed?

As for the smoke test... why did it pull the water out of my toilet basins? Could it be that the Pressure on the lines was to high / low? Would leaving a vent uncapped help to get the test to work?

Thanks for your help!!


06:53PM | 06/11/07
Member Since: 06/10/07
1 lifetime posts
I have never used the peppermint. I use the smoke test exclusively and regularly. It is extremely accurate if performed properly. If the water is being blown out of the traps, air CFM pressure is too high. My smoke machine allows total control over the cfm and rpm of the motor allowing you to reduce pressure and blow in smoke close to a trap. The other alternative is to blow in smoke from further away, ie. on the roof at the toilet vent. Keep the smoke generator out of the house in any event. Use only half of the smoke coming out of the smoker if that prevents the water from blowing out of the trap. If the plumber was not able to smoke without blowing the water out of the trap, he wasn't able to do a proper and accurate test. He needs to come back and do it again. Smoke is extremely accurate.

Do not block the vents on the roof for the test, this will only increase the pressure in the lines. I used to cover them 50 percent with gaffers tape. This gives you just a bit of back pressure and makes the smoke migrate faster through a leak. You want the smoke to travel the full length of the pipes.

Also, sometimes the leaks are buried in the walls and it may take a while for the smoke to fill voids before it moves out where it can be seen. The plumber should be able to generate smoke for at least 15 minutes non stop. You may find a leak in less time, but I would not be comfortable smoking testing for less time. Search for smoke in darkened roomlight with a powerful flashlight.


01:12AM | 09/09/07
Member Since: 09/08/07
1 lifetime posts
Have you recently purchased a new HE washing machine or perhaps a snew shower or large bathtub?

I had the same problem, but figured out it was all due to the HE washer and the huge tub (two seperate lines out of the house), that pulled the water out of the sanitary tees/traps and allowed the gases to escape the toilets and such. Might want to check into that. No solutione xcept to make new major lines out fo the house.. Or just keep tabs on flushing the toilets after a big bath or after washing clothes, or dishes if you have an industrial dishwasher.

Just trying to make sense of life... and building better houses for less.


06:15PM | 09/09/07
Member Since: 11/20/05
7 lifetime posts
I should have written sooner... We found the problem.

I hired a plumber (who couldn't perform the smoke test properly)... we continued to use them... to the tune of over $1000... they used cameras... and pulled 5 nails out of my sink vent stack.... and yet the smell persisted.

Prior to that I reseated the toilet a couple times and even replaced it!

Eventually I called "American Leak Detection" here in Dallas... THEY WERE AMAZING. They performed the smoke test and found the problem within minutes. I cut open the wall where the smoke was... traced it back... and found ANOTHER NAIL that had caused the pipe to crack. The crack was about 4 inches long.

I fixed the length of pipe myself... and have not had a problem since. On a side note... they charged about $200.. and it cost me about $20 in supplies to fix it myself.... much cheaper than the first set of plumbers!

I am a bit annoyed that the home builder decided to use my vent stack instead of a stud to attach our siding to. (The vent stack was in an outside wall). But I am so relieved that we fixed the problem.

The most obnoxious thing was that the original plumbers never smelled the odor... it was intermittant and I swear they thought I was crazy!

Sadly now I have to re-wallpaper the room... but there is nothing nicer than an odor free bathroom!


04:54PM | 03/30/09
Member Since: 03/29/09
1 lifetime posts
hi there,

i know this is a very old post. but, it doesn't hurt to ask. can you tell me the name of the first plumbers you hired that cost you over $1000? I'm having the same problem and live in Dallas and do not want to spend that kind of money and still have the problem hiring bad plumbers!!

Thank you!!


12:01AM | 01/03/18
I have four bathrooms in the house the furthest one from the tank you have any ideas.

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