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Why Does My Shower Drain Smell Like Sewage?

Why does my shower drain smell? If you’re one of the Birmingham homeowners whose nose has asked this question recently, Douglas Cooling & Heating is here to help. Learn the causes of shower drain odors as well as the solutions to stop them. When do-it-yourself solutions don’t eliminate the smell, contact your trusted, local plumber for professional solutions to stop the stench and protect your plumbing system.

Why Does My Shower Drain Smell?

Shower drain odors have a few common causes:

  • Mold growth in the drain
  • Clogs and debris in the drain
  • Sewer gasses escaping the drain

These causes produce different odors emanating from a shower drain. Identifying the scent of the odor helps homeowners pinpoint its cause.

Why Does My Shower Drain Smell Musty?

A musty smell rising from a shower drain is produced by mold growth. Underneath the shower drain cover, mold is able to grow. This is due to cellulose materials from the hair, body oils, and soap scum sticking in bathroom drains as wastewater flows out the drain pipe. Along with the moisture from the water, this creates an environment for mold growth in the drain system.

Why Do I Have a Sewer Smell Coming From My Drain?

If the drain smells like sewage or sewer gas, a sewage odor can indicate various plumbing system issues.

Biofilm Growth

A rotten egg smell is often caused by biofilm buildup. Biofilm is a sticky, slimy layer of bacteria that forms on surfaces over time, and it can be found in many places in our homes, including our showers. When biofilm begins to accumulate in your shower drain, it can lead to an unpleasant odor that can be hard to eliminate. The bacteria in the biofilm produce waste products that cause a distinctive smell, and the longer the biofilm is left untreated, the stronger the sewage odor will become. This is because biofilm is hard to remove and can continue to grow if not addressed properly.

Blocked Vent Pipe Allows Sewage Gasses to Back Up

Plumbing vents play an essential role in maintaining an efficient and healthy plumbing system. These vent pipes are designed to help regulate and control air pressure, thus preventing dangerous and toxic gasses from building up inside the drain line. When a vent pipe becomes blocked or clogged, it can cause a range of issues, such as unpleasant odors and a sewer smell coming from your shower drain. This occurrence is often due to sewage gasses building up in the pipeline, which can cause a foul odor that can be quite unpleasant.

Dry P-Trap Causes Sewage Gasses to Escape

A P-trap is a U-shaped pipe that is part of your drain line. Water is constantly flowing through the P-trap, thereby providing an almost permanent seal that blocks any gas from entering your home. Thanks to the unique structure of a P-trap, the curved section of the pipe helps in retaining a small amount of water between uses. This water serves as a barrier and acts as a cushion, blocking any such materials that might return through the drain. Without the P-trap, there would be no barrier, and sewer gasses would continuously enter your home, creating unhealthy and unpleasant sewer odors.

If you’re experiencing an unpleasant sewer smell emanating from your shower drain, there’s a high chance that it’s due to a P-trap that’s dry. Frequent gaps between shower usage can cause the water to evaporate, leaving an opening for the sewer gasses to seep into your home. Not only is this sewer gas odor repulsive, but inhaling sewer gas can potentially lead to health risks, making it all the more essential to address the issue.

A Clogged Shower Drain Leads to Sewage Smell

A sewage smell can also be an indicator of a drain clog. Clogged drains can occur due to a variety of reasons, such as the buildup of hair and soap scum, which causes a blockage in the drainage pipes. This blockage prevents water from properly flowing out of your shower drain, which in turn leads to stagnant water accumulating in the pipes, forming a breeding ground for germs and bacteria. A clogged drain not only results in an unpleasant odor but can also pose a risk to your health, particularly if you have a weakened immune system.

Leaking Drain Pipes Can Cause a Sewage Smell

If you’ve been struggling with a sewer smell emanating from your shower, the root cause might be damaged drain pipes. These pipes carry wastewater from your shower to your main sewer line and onto the municipal sewer system or septic tank. As they age, they can crack, rust, or develop leaks.

If this happens, wastewater won’t flow properly to the sewer line or septic tank. Instead, it can seep out into the surrounding area, including the flooring beneath your shower. Beyond the unpleasant smell, leaking wastewater can cause extensive damage and even pose a health risk. A foul odor is typically the first and most noticeable sign of damaged pipes, but you should also look out for discoloration or warping in nearby flooring or walls.

DIY Solutions to Get Rid of the Smell in Your Bathroom

Try the following DIY solutions to eliminate foul shower drain smells.

Manually Clean Drain

After each shower, clear the drain cover of hair and soap scum buildup. Pull as much of this material out of the drain as possible. Use a drain cleaning tool like a drain snake to reach deeper below the drain opening. 

Treat Drains for Mold Growth

Prevent mold growth and a musty shower drain odors –  treat your drains using this process:

  1. Remove the drain strainer and clean it.
  2. Use an old toothbrush or drain brush to scrub the drain and sprinkle one cup baking soda down the drain. 
  3. Next, add one cup of white vinegar, slowly pouring it into the drain. 
  4. Cover the drain and allow the baking soda and vinegar solution to fizz and soak, working to kill mold and other odor-causing bacteria. 
  5. Flush with hot water after about 10 minutes.

Fix a Dry P-Trap

When a P-trap goes dry, sewage odor often results. Look down your drain – do you see water? If not, the P-trap is dry. Remedy a dry P-trap with the following process:

  1. Pour up to two cups of water into the drain.
  2. Wait one hour.
  3. Look into the drain to see if water remains – if not, time to call a plumber for P-trap repair.
  4. If the shower isn’t regularly used, also add four ounces of mineral oil to the water to prevent evaporation.

Clear a Blocked Vent Pipe

During extreme temperatures, plumbing vents on the roof may become blocked by snow and ice, causing sewer odor backup in your shower drain. Safely clear the roof of snow and ice. If plumbing vents have iced up, locate the vent in the home’s attic and use a hairdryer at the vent’s roof exit to melt the blockage.

Let a Professional Plumber Help with Your Smelly Drains

When the above DIY solutions don’t offer relief, the professional plumber technicians at Douglas Cooling & Heating have advanced solutions to eliminate foul shower drain smells. Depending on the source of your shower drain smell, the following solutions provide relief:

  • Drain cleaning: Our professional drain cleaning methods clear tough bathroom plumbing clogs that homeowners cannot fully access.
  • Pipe repair: If leaking pipes are causing your shower to smell like sewage, we can fix your damaged drain lines to stop leaks and bad odors.
  • P-trap repair or replacement: A cracked P-trap doesn’t hold the water necessary to do its job. We will make repairs or replace the P-trap components so water stays in, which also prevents leaks and water damage beneath the shower drain.
  • Plumbing vent inspection: Our team will inspect plumbing vents for blockages and damage that cause sewer odor backup in your drains. We identify the issue and make the appropriate repairs.

Douglas Cooling & Heating Rids Your Bathroom of Drain Odors

If you smell sewage or a sewer gas smell from the drain in your shower, do not let the problem go unresolved. If the above DIY solutions haven’t helped, call Douglas Cooling & Heating for professional drain cleaning and plumbing services to rid your shower and bathtub drains of clogs and other issues causing the sewage smell.

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