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You are in Phoenix. We also have a Tucson site.

You are in Phoenix. We also have a Tucson site.

What's That Smell? Unmasking the Mystery of Sewage Odor in Your Home

Behind every trip to the bathroom is a plumbing infrastructure that most people hardly think about. There's water in the toilet, sewage pipes underneath the house, and a septic tank or sewer lines in the yard.

You might wonder, "Why does my house smell like sewage?"

The truth is that there are a lot of different possible origins for oddly stinky smells in your home - and some of them could be creating serious health hazards.

So, what's that terrible smell, and how do you determine if it's a health hazard? Read on to learn more about possible plumbing problems and what's causing the unwelcome smell in your home. 

Dried Out P Trap

Part of your plumbing's anatomy is something called a P-trap. This P-shaped pipe should hold a small amount of water on the side of the horizontal P piping. 

If the plumbing and P-trap are working correctly, a small amount of water is sitting in the P-trap. This water helps prevent the sewer gases and smells from returning to your home. 

If the P-trap dries out, you won't have that trap in place. For example, if you've ever gone a long time and not used a laundry sink, you might notice the noxious smell. It's likely because of nonuse that the P-trap dried out. 

Clogged P Traps 

Once you understand and can visualize the P-trap, you can also easily understand how those bends in the plumbing make for an easy place for a clog. 

The bend in the P-trap is a common spot in your plumbing to collect hair, dirt, soap, grime, and even human objects that go through the drain. Once things sit for a while, the smell gets worse. 

So, in this case, it might not be directly sewer smells, but you'll think it is because it can be an equally stinky odor. 

Vent Pipe 

Your home is engineered to let out smells and keep air flowing. Around the roof, your home should have several vents to let gases escape. 

These vents can get clogged by everything from leaf and tree debris to animals. When the vent gets clogged, the gases that should be moving out of your house have nowhere to go except back into your home. 

Keeping these vents cleaned out can prevent the sewer smell from backing up and coming into the house. 

Floor Drains 

Have you ever been in the shower while the water and soap are collecting down by your feet? You probably recognize quickly that your floor drain gets clogged. 

When a floor drain clogs with hair and soap and then sits there, the smell can get pretty rank. It can smell like sewage, resulting from a clogged drain

Clogged Drain

It's not uncommon for other drains in your home to clog too, including in your laundry room or kitchen sink. 

These are two places where debris will likely go down the drain. It can get caught in the drain and sit there. Over time, it starts to break down and gets very smelly. You might think it smells like sewer gas coming up through the drain. 

Most likely, whatever is clogging the drain is also the culprit for the smell. 

Missing Clean-Out Plugs or Caps 

Another part of your home's plumbing anatomy is called a clean-out plug or cap. These small caps are located at access points to your main sewer line. Finding a clean-out plug at the foundation where the plumbing goes into the main sewer line would be common.  

These caps have the job of preventing sewer gases from traveling back into your home. The problem arises when plugs or caps fall off, and nothing is stopping the gases from flowing back into your pipes and home. 

Bad Wax Ring on the Toilet

You might expect sewer or bad smells to come in or around your toilet. But that shouldn't be the case if the toilet is plumbed correctly.

A wax ring connects your toilet to the floor and the plumbing beyond. If the seal is broken on the wax ring, the toilet isn't air or watertight. This could allow smells from the plumbing system to seep into your home. 

If you suspect sewage smells are coming from your toilet, you'll want to have an experienced plumber look at the wax ring to ensure it's sealed. 

Sewer or Septic Pipe Leaks

Beyond just the plumbing of your home lies the sewer lines that carry waste and water away from your home. These sewer lines can leak. 

When there's a leak, the sewage may not move correctly through the lines, and the smells back up into your home.  

You may notice your sinks are slow to drain or that even your toilet gurgles. These are signs of distress in the sewer lines that need to be checked out by a professional. 

Sewer Line Breaks

A break in your sewer line might be a more serious reason you get sewage odors creeping into your home. Once there's any kind of break, the smell will inevitably work its way back into the inside or perimeter of your home. 

A sewer line might break for any number of reasons. Some sewer lines are just old, and their age causes them to break.  

Sewer lines often run under the grass in your yard. The sewer line could break if you park or drive in your yard. 

If you live in an earthquake zone and have experienced tremors, this can cause a break in the sewer line.

Loose Connections

A loose connection is another more serious issue that could cause sewer odors in your home. A loose connection between sewer lines would let odors seep into your home.  

Another spot where you might have a loose connection is by vent pipe. A loose connection in a vent pipe or sewer line will likely be between your walls and will require a professional plumber to address it. 

How to Prevent Sewer Smells in Your Home

Homeowners can do some routine things to prevent sewer gas smells in your home. Let's take a closer look at what you can do to protect your home. 

Smoke Testing 

If you're already concerned you have a leak, then you might want to look into smoke testing. This procedure helps plumbers identify where issues might be located in your sewer system. 

Thick white smoke is injected into sewer lines or drainpipes, once the smoke is in place, the plumber can see where the smoke is escaping. Even for minor issues, this method prevents a small problem from becoming a big one. 

Clean Out Your Drains

Over time the drains in your home collect all the things that inevitably go down them. This can include hair, soap residue, and other debris that collect in the base of your drains.  

With routine drain cleaning, you can get rid of the bad smells coming up from your plumbing. Pull up the drain and remove unwanted debris collected there. Then run several gallons of very hot water down the drain to help clean it. 

Keep Water in All of the Traps

To prevent sewage backup and sewage smells from coming up into your sinks and showers, make sure there's water in your P-traps. 

Remember, the P-trap is the little dip in the pipe where you want water. You can do this by making sure you regularly run water, so the P-trap doesn't dry out.  

Vent Stack Free from Debris

Your roof has a vent stack that allows odors to escape. Make sure this is kept clear of debris. If you have trees nearby, make sure branches and leaves don't block the vent stack. 

Dangers of Sewer Gas

Aside from sewer gases smelling like rotten eggs and being otherwise quite unpleasant, they can also be dangerous for you.  

Decomposing organic matter can contain hydrogen sulfide, ammonia, and methane. Aside from the rotten egg smell, a small leak probably isn't dangerous. But high concentrations of sewer gases can impact your health.

Extended high concentrations of sewer gases can cause:

  • Headaches

  • Dizziness 

  • Nausea

  • Vomiting

  • Memory loss

  • Poisoning 

  • Asphyxiation

In high concentrations, it can increase the risk of fire or an explosion in your home. 

If you notice sewer smells, contact a professional plumber who can use their leak detection strategies to quickly identify the problem before it impacts your health. 

Why Does My House Smell Like Sewage? 

So, why does your house smell like sewage? There are a number of plumbing-related issues that could be causing the unwelcome stink to creep into your home. If you notice smelly sewer odors cramping the comfort of your home, it may be time to call in the professionals. At Parker & Sons, we understand that plumbing issues can be overwhelming and disruptive. We make it our priority to respond quickly and efficiently, providing timely solutions for all your plumbing needs, big or small! Contact us today for a free estimate!


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