house smells like sewage

Why Does My House Smell Like Sewage?

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By 1-800 Plumber +Air

November 30, -0001

When it comes to a happy home, the unpleasant odor of sewage doesn't exactly fit in the picture. Unfortunately, it's a more common (and far stinkier) problem than you might imagine.

A sewer smell in the bathroom, kitchen or laundry areas is usually a red flag that something has gone wrong with your plumbing. The causes of a sewer smell indoors can range from minor, easy-to-fix issues to major problems that require professional attention. If you've cleaned your home and are still battling the stink of sewage, it's time to dig a little deeper to find the source of the smell.

In addition to being an annoyance to your sense of smell, a sewage odor can actually be a hazard to your health. One of the main gasses in sewage is methane, which can be highly flammable if allowed to accumulate in large amounts. Also, high methane levels can be a serious health risk for you and your family, causing symptoms ranging from headaches and nausea to loss of consciousness and suffocation.

This much is clear: a sewage smell in your home is definitely not something to ignore. So, we've created a guide to help you tackle the problem head-on and figure out what is causing a sewer smell. You may be able to resolve the issue on your own, or you may need to call in a professional - but taking action is essential.

Common Sources Of Sewer Odors Inside the House

If you're anything like most people, when you smell sewage inside your home, you immediately go to check your toilets. In some cases, a deep cleaning could do the trick. In other instances, all the cleaners and air fresheners in the world don't seem to make a dent in the odor.

When this happens, you're most likely facing a larger issue. And while it could be a problem with your toilet, the smell could actually originate from your shower drain or your sink. When it comes to a sewage smell, shower drains are one of the most common culprits.

Use your nose - and this guide - to pinpoint exactly where the sewage smell is coming from, so you can get a better idea of the issue at hand.

Odors From Your Shower Drain

If your bathroom has the distinct odor of sewage, the shower drain is often the first spot you should check. There are two common causes of a smelly shower drain: a P-trap issue or biofilm accumulation.

P-trap Issues

A P-trap is the U-shaped PVC or stainless steel pipe that runs underneath tubs/shower and bathroom and kitchen sinks.

P-traps have a few key purposes:

  • Their shape is specifically designed so that they can hold enough water to prevent gas and fumes from traveling up through the pipe and into your home. By blocking seeping sewer gasses, P-traps keep your home smelling fresh and protect your health.

  • These sections of pipe are also intended to defend against drain clogs. Ideally, a functioning P-trap eliminates excess debris to prevent a clog.

  • Finally, the curved shape of a P-trap makes it the perfect place to catch anything you've accidentally dropped down the drain. The P-trap can catch small items such as rings and earrings, so you can rescue them before they are washed away completely.

In order to work properly, a P-trap should consistently contain ("trap") enough water to block sewer gas. However, if you rarely use one or more showers in your home, it is common for the P-trap to dry out. Or, a leaky P-trap could be allowing water to escape.

Problem: A dry P-trap

How to Fix it:

  1. If the shower is one you don't usually use, try running the water for a few minutes. This should be enough water to refill the P-trap and fix the problem.

  2. If the smell persists, try pouring water into every drain in your home, including sinks, showers, and toilets (about 1 quart per drain).

  3. If that still doesn't get rid of the smell, contact a professional plumber to inspect or replace the P-trap.

Biofilm Buildup

Every time we shower, we wash a wide variety of products down the drain, along with hair, skin cells, dirt, and other natural debris. Regularly cleaning your shower can help, but it's not uncommon for this residue to slowly build up over time.

"Biofilm accumulation" can lead to clogs, slow drainage, and bad odors. Eventually, this buildup can even accumulate in the pipes that run beneath your shower. And because the bacteria in biofilm creates a sticky substance, it clings to pipes and can be difficult to get rid of. Both the bacteria and the decomposing debris in the biofilm release an unpleasant smell - and before long, your bathroom can start to stink.

Problem: Biofilm accumulation

How to Fix it: With a homemade solution of vinegar, water, and baking soda, you can strip biofilm from your drain and pipes without causing damage. Here's how:

  1. Using a screwdriver, carefully remove the shower drain.

  2. Boil 5-10 quarts of water, then allow it to cool slightly (aim for 150 degrees Fahrenheit).

  3. Slowly pour the hot water down your shower drain. Then, pour one cup of white vinegar down the drain.

  4. Immediately dump ½ cup of baking soda into the drain.

  5. Wait two hours, then pour another gallon of hot water down the shower drain.

  6. With a drain brush, gently clear out any stubborn debris.

If this DIY solution for stinky shower drains doesn't work, 1-800-Plumber has another option - 800-Bio, an environmentally-safe, ready-to-use solution created to restore and maintain normal flow of drains. Just pour 2oz down your drains every day for the first week, followed by the recommended monthly treatments to continuously keep your pipes flowing.

Otherwise, it's time to contact a professional. Or, if you would prefer to skip straight to a plumbing inspection, a professional consultation is never a bad idea.

Odors From Your Toilet

When you smell a foul odor in your bathroom, your first instinct is likely to check the toilet. And sometimes, a good cleaning and a few flushes will do the trick.

But other times, there are other reasons for a sewer smell coming from the toilet, including:

  • An improperly installed or cracked vent pipe

  • A broken/loose seal

  • A damaged toilet

Improperly Installed or Cracked Vent Pipe

Does the smell seem to be originating near the walls surrounding your toilet? If so, an improperly installed or cut vent pipe could be to blame.

A vent pipe regulates air pressure in your plumbing system and also redirects odors, so they end up outside, not inside, your home. But if a vent pipe is not correctly installed, it can reroute those odors directly into your bathroom. A vent pipe can also become cracked, allowing the smells to escape and enter your home.

Problem: A vent pipe that is incorrectly installed or cracked

How to fix it: Contact a professional plumber to diagnose vent pipe problems and provide a proper solution. Depending on the issue, your plumber may need to replace the vent pipe entirely.

A Broken or Loose Seal

Two important seals attach a toilet to its drain. If either seal is loose, incorrectly installed, or broken, sewer gasses can seep into your bathroom.

How do you know if a toilet seal is broken or loose? A few key signs include:

  • A toilet bowl that does not fill up properly

  • Water pooling in and around your toilet, leaking from the bottom of the toilet

If the toilet leaks from the wax ring (intended to prevent leakage and create a tight seal on the toilet drain), sewage can easily seep out. The sewage and bacteria growing in accumulating water produce a bad smell.

Problem: One or both of the toilet seals are broken or loose

How to Fix it: Check to see if your toilet bowl seems to be loose or wobbly. If so, this may have caused damage to the wax ring. You can attempt to reset it with a new wax ring, but most homeowners opt to hire a professional. Or, you can try to apply a fresh line of caulk to the toilet's seals and the bolt holes where the toilet is secured to the floor. Contact a plumber if neither of these DIY fixes for a broken toilet seal works.

A Damaged Toilet

Even if your toilet appears to be working fine, minor damage can result in sewer seepage. Take a close look at the parts of the toilet surrounding the bolts that fasten it to the ground. Even very small cracks can allow sewer gas to pass through. Sometimes, using a drain snake could have caused cracking.

Problem: A damaged toilet

How to Fix it: Contact a professional to repair or install a new toilet.

Odors From Your Sink

One of the final places you can check is your bathroom sink. The sink drain can develop a dry P-trap or biofilm buildup like your shower drains. Another common source of odor coming from the sink drain is a buildup in the overflow.

Buildup In the Overflow

Many sinks have an overflow mechanism, which appears as a hole near the top of the sink. This mechanism is intended to serve as an outlet in the event the sink is filled with water to prevent it from overflowing. The overflow area can easily build up mildew and grime, leading to a bad smell.

A quick and thorough cleaning can usually take care of this problem. Using a small bottle brush, scrub inside the overflow area. Then, apply a solution of ½ water and ½ chlorine bleach in and around the overflow to eliminate bacteria and odors.

Problem: A buildup of grime and mildew in the overflow

How to fix it: Clean the overflow area using the abovementioned steps. If the smell continues to be an issue, contact a plumber.

When You Need a Plumber

We've covered some of the most common reasons for a sewage smell in the bathroom, but other factors could also be at play. For example, your laundry room could have many of the same issues (a dry P-trap or a clogged vent pipe or drain). Or, the issue could be with the actual water - caused by bacteria or hydrogen sulfide.

If none of our suggested fixes work to get rid of the smell, contact a trusted plumbing professional. Or, if you simply don't feel comfortable attempting a repair, don't hesitate to reach out to a plumber.

Many plumbing problems are far beyond an easy DIY fix, including:

When in doubt, let a professional plumber help.

Frequently-Asked Questions

Why does my bathroom smell like sewage?

Sewage smell can be caused by a multitude of factors, including:

  • Broken or leaking pipes

  • Damaged toilets or toilet seals

  • Shower or sink drain issues

  • The buildup of biofilm, grime, and mildew

How do I get rid of a sewage smell in my bathroom?

First, try to pinpoint where the sewage smell is coming from. Then, use our guide to see if you can figure out exactly what is causing the smell. You might be able to resolve the problem on your own. In many cases, contacting a plumber is your best bet.

How does a plumber get rid of a sewage smell?

The fix depends largely on the cause of the smell. However, a professional can easily determine what is causing sewage smells in your home. With a thorough inspection, a plumber will assess the area to find the root of the problem. Then, they can perform the repairs (or replacement) as needed.

Plumbers with Experience You Can Count On

Dealing with plumbing problems can be a major hassle, but knowing exactly who to call can help. With service areas across the US, 1-800-Plumber +Air is one of the industry's leading companies and a name you can trust when it matters most.

For more than 20 years, our team of skilled professionals has provided the highest standard of quality when it comes to customer service, workmanship, and integrity. Whether you're dealing with a mysterious sewage smell, a leak, or a large-scale commercial plumbing project, 1-800-Plumber +Air is ready to help.

For more information about what to do about a sewage smell in your home, contact us 24/7 at 1-800-Plumber or schedule your service call online today!

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