Plumbing in the Home/sewer smell


QUESTION: When we run water in the house, shower, laundry there is a smell that is like a sewer smell coming from the laundry room now there is a drain on the floor and that is where the main water lines are too i have tried bleach in the drains and filling floor drain with water helped for awhile we are on a cement slab also hope you can help

ANSWER: Hi Peggy,
This is a common problem with floor drains.  Every drain has a trap and when not used frequently, the water in the trap evaporates.  The purpose of the water is to forma a water seal so sewer gas does not enter the house.  Adding a quart or so of water to the floor drain trap weekly should take care of this problem.

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QUESTION: I have tried this but it's everyday and right after we run washer or shower do I add water everyday and doesn't the water from the draining fill the pipes so gas doesn't come back up sorry I'm a great grama and n plumbing experience just a smelly house

Okay, the trap issue is the most common one. Another thing that causes problems is poor or blocked venting.

By venting, I don't mean having a window open. Plumbing drain systems must be vented. If they are not vented properly or the vents are blocked in some way, the water traveling through the pipes will create a siphon and suck water out of the traps thus opening them to allowing sewer gas to come back up the pipes into the house.

The vent pipes for a drainage system usually go all the way up through the house and out through the roof. There are many things that can block the airflow in these vent pipes. Snow coverage, Frost closure, bird nests and insects etc.

This may be something you will need to have a plumbing professional investigate. Laundry drainage especially is prone to blockage of the drain pipes from soap scum and lint in the drain water. Having the drain lines professionally cleaned, including the vent pipes to the roof would be beneficial and might solve this problem.
Good luck,

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Dana Bostick


Pretty much any residential plumbing questions. For "item specific" details such as a specific model of fixture, I will need to research and there may not be any useful information available. Note: I live and work in Southern California. We do not, as a rule, use hot water or steam heating systems, oil fired boilers or private water wells so my knowledge in those areas is pretty limited. There are others here on AllExerts that can probably answer those questions better.


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