Why Does My Basement Smell Like Sewer? 6 Possible Reasons

It can be really alarming to wander into your basement and get strike with the smell of a sewer. Instantly you wonder, “What is that odor?” and “Where is it coming from”? In many instances, it can be a swift and painless correct.

There are occasions, however, when the difficulty is severe and needs a expert. Before you get in touch with for help, verify these widespread issues. You may be ready to take care of the problem with out incurring a significant fix invoice.

Why Does My Basement Smell Like Sewer? (6 Reasons)

1. A Water Trap That Has Dried Out

flooded basement
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Numerous basements have unused drains. Sinks, laundry tubs, and flooring drains contain pipes that keep a little sum of h2o. They are named S or U-formed pipes. If the device is not used for a whilst, the h2o in the pipe can dry up. The result is a smelly drain.

Pouring a gallon of h2o into the smelly drain will refill the U or S-pipe and rid the drain of the odor. We also advise you open up the home windows to air out the area.

2. Toilet Trap

Toilets employed routinely have h2o movement in and out of the trap. If you reside in a property with a basement that does not get a great deal of use, the bathroom can dry out. The water in the lure of a bathroom can evaporate. Sewer fuel can arrive up from the trap and lead to your basement to scent like rotten eggs.

It is advisable that you flush the rest room routinely to stop the entice from drying out.

3. Toilet Wax-Ring Seal

white ceramic toilet and sink in a bathroom
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The bathroom flange is the round pipe fitting that connects the toilet to the drain pipe and flooring. A wax ring seal is set up in between the rest room and the flooring. If it is not installed properly or has turn out to be unfastened, the rest room will be unstable and allow gasoline to enter the space. The awful odor can also come from a dried-out wax seal.

The issue can be fixed by changing the dried-out or faulty wax ring. You can obtain one at your nearby components keep. Wax rings are universal but arrive in diverse sizes, however. Be positive to evaluate your toilet to figure out the appropriate dimension.

4. Cleanout Plug is Missing

There is a lure beneath the floor drain in your basement. There is a plug positioned in the part of the drain that bypasses the h2o trap. The plug prevents sewer gasoline from coming into your residence. If, after cleansing the drain, the plug is not replaced correctly, the odor will occur up from the drain.

Check the plug to be positive it is inserted accurately. If the plug is missing, you can acquire one particular at your neighborhood hardware keep. Be sure to obtain the suitable size for your drain.

5. Ejector Pit

washing machine at the bathroom
Image Credit: Piqsels

An ejector pit or sump basin residences the pump that carries wastewater from the basement laundry area and bathroom to the sewer line. The pit is vented and sealed. If the seals are broken, it will permit sewer gasoline to enter the residence and trigger a sewer smell.

If the issue is not with the vent or seal, the dilemma may be with the actual aspect. In that scenario, we recommend you get the guidance of a expert.

6. Damage to Sewer Line

Hurt to a nearby sewer line can make your residence smell like a sewer. If the harm is close by, the sewer water can leak into the floor and ultimately conclude up in the sump pit of your home.

It is advisable that you phone a specialist to check for a leak. If a leak is identified, they will recommend you of the subsequent action and give you an estimate for the necessary repairs.

Tips for Prevention

In some cases, issues happen that are beyond our manage. Broken pipes and sewer strains can result in issues for house owners. Below are some suggestions, nevertheless, to preserve the sewer smells out of your home.

  • Keep water in the traps. Traps are in sinks, toilets, floor drains, and walls. Knowing where they are is the first step to prevention. Any traps that are rarely used can dry out. To slow the evaporation of the water in the traps, add some vegetable oil.
  • Keep drains clean. Drains are prone to build-up of debris, hair clogs, and foreign objects. Regular cleaning of the drains with a wire hanger or small drain snake will help to prevent build-up and remove any objects or debris that may cause a problem. Once the drain has been cleaned, flush it with four to five gallons of hot tap water. Do not use boiling water.
  • Clear blocked drains. If you have a blocked drain that you cannot clear yourself, you may need to call a professional.
Installing sewer pipe under the house
Image Credit: Radovan1, Shutterstock

Is Sewer Gas Dangerous?

Sewer fuel can incorporate ammonia, methane and hydrogen sulfide. The rotten egg smell comes from the hydrogen sulfide. Publicity to higher concentrations of sewer fuel is unusual in a home. Publicity to large concentrations of the gasoline is a lot more widespread in industrial amenities.

Symptoms from in excess of exposure to sewer fuel incorporate dizziness, headache, vomiting, nausea, poisoning, asphyxiation, and memory loss.

As a precaution, if you smell sewer gasoline in your home, open some windows right away.


In many cases, the smell of sewer gasoline is anything that can be resolved simply. If the difficulty is not an straightforward fix, look for the advice of a expert. As usually, if you are experiencing any of the signs detailed over, seek health-related attention immediately.


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