If you smell a sewer odor in your basement, you definitely have a plumbing problem. The foul odor that you smell is called sewer gas, and it's made up of a combination of gases including methane, sulfur dioxide, and nitrous oxides. This gas forms as household and sewer waste decays. Below you'll learn what's causing this rancid odor and how you can get rid of the smell in your basement.
Floor Drain Problems
If the floor drain in your basement is hardly ever used, sewer gas can leak up through the drain. A drain trap connects to the plumbing pipes underneath the drain. One of the functions of the trap is to hold water and keep sewer gases from escaping through the drain. If the drain isn't used very often, the water eventually evaporates, which allows the gases to escape into your basement.
To remedy the sewer odor due to a dry drain trap, pour a gallon of water down into the drain. After adding the water, pour two teaspoons of cooking oil down the drain. The oil will float on top of the water and form a seal that helps to prevent the water from evaporating so quickly.
Basement Bathroom Issues
If you have a toilet, shower, or sink in your basement that you hardly ever use, this could be the cause of the sewer gas smell. Sink and shower traps can dry up just like the floor drain and cause the gas to seep up into the basement. Flush the toilet and run water into the sink and shower drains to clear the smell.
Damaged Toilet Seal
If you do use your basement bathroom frequently and a dry trap isn't the problem, check the wax ring on the bottom of your toilet. The wax seal is located on top of the toilet flange that connects to the base of the toilet. Sewer gases can leak into your basement through a damaged or deteriorated seal.
Purchase a wax toilet seal at your local home improvement store. Follow these easy instructions for replacing the wax seal:
- Turn off the water supply to the toilet by turning the knob that's connected to the pipe on the wall behind your toilet.
- Remove the lid from the toilet tank and flush your toilet. Press down on the handle until most of the water drains out of the toilet tank.
- Use a plastic container to dip out any water that's left inside of the tank.
- Disconnect the water supply from the toilet by loosening the nut on the water supply valve behind the toilet.
- Remove the caps from the base of the toilet and remove the nuts with a wrench.
- Grasp the toilet underneath the bowl and move it side to side to loosen it from the seal.
- Lift up on the toilet, remove it, and place it out of the way.
- Use a plastic putty knife to scrape away any residue from the old seal that's left on the flange.
- Center the new seal on the flange and press it down to secure it to the flange.
- Place the toilet back on the flange and line up the holes with the bolts.
- Put the nuts back on the bolts and tighten them with the wrench.
- Reattach the water supply to the toilet and turn on the water.
Broken Sewer Line
If your drains or toilet seal isn't the cause of the sewer smell in your basement, you have a broken sewer line. This causes the sewer water to penetrate the ground around your basement foundation. Contact a qualified plumber, at a site like http://www.aabsoluteplumbing.com, to test the sewer line and make the necessary repairs.