An otherwise relaxing shower can quickly turn sour when your bathroom is filled with a sudden sewage-like stench.
We at Ben’s Plumbing know that a smelly shower drain is more than just a nuisance. It can be a sign of larger plumbing problems that, if neglected, can result in expensive repairs. This guide will help you understand the causes behind it and how to fix a smelly shower drain for good.
Causes of a Smelly Shower Drain
1. Dried-Out P-Trap
A dry P-trap is often the main reason your shower drain smells like sewage. This curved pipe is designed to hold a small amount of water that blocks sewer gases from coming up. When that water evaporates (usually in guest bathrooms or unused showers), sewer gases rise, and suddenly your bathroom smells like sewage.
How to fix: Run water in the shower for a minute or two to refill the trap. For long-term unused drains, pour a tablespoon of mineral oil down the drain to slow evaporation.
2. Biofilm Buildup
A sticky layer of grime made up of body oils, soap scum, shampoo, and dead skin can cling to the inside of your pipes. This gunk forms what’s called biofilm. This layer becomes a cozy spot for bacteria to grow—and that’s often why your shower drain starts smelling musty or like mildew.
How to fix: Pour a mixture of baking soda and vinegar down the drain. Let it fizz for 15 minutes, then flush with boiling water. For persistent issues, professional cleaning may be required.
3. Clogged or Slow Drains
Ever notice your shower draining slower than usual, even if it’s not fully clogged? That leftover hair and soap scum might be the culprit and cause bacteria to grow. The result? A foul smell is coming from the shower drain that might even resemble a dead animal.
How to fix: Use a drain snake or hair catcher to remove visible debris. Follow up with a baking soda and vinegar flush. For tougher clogs, a plumber’s auger or hydro-jetting may be necessary.
4. Sewer Line Problems
Sometimes, the problem isn’t in your bathroom at all. A cracked sewer pipe or a blocked vent stack can send odors wafting up through your drains, no matter how much you clean. If you’ve tried everything and the smell just won’t quit, you could be dealing with a deeper, more serious issue.
How to fix: These are not DIY-friendly problems. Call Ben’s Plumbing. Diagnosing and repairing sewer line problems is our specialty.
5. Mold and Mildew
Mold loves dark, damp places—like the inside of your shower drain. If you catch a whiff of mildew, especially after a hot shower, mold might be thriving out of sight.
How to fix: Scrub the drain cover and surrounding area with an old toothbrush dipped in a bleach-and-water solution. If the smell returns, a deeper inspection for hidden mold is in order.
6. Leaky Seals or Cracks
Tiny cracks in the pipes or worn-out seals can let water and gases escape, sometimes making your shower smell like urine—or worse. These leaks often go unnoticed, especially if your shower floor is tiled.
How to fix: If visual inspection reveals cracked grout or water around the base, it’s time to consult professionals.
7. Stagnant Water in Hidden Areas
Sometimes, water gets trapped in areas like the overflow drain or deeper parts of the pipe. This stagnant water smell can become quite strong over time.
How to fix: Sometimes, only a thorough professional cleaning—or even replacing old pipes—will do the trick.
How to Prevent the Foul Smell of the Shower?
Preventing that nasty smell is easier than fixing it later — a few simple habits can keep your bathroom smelling fresh:
- Run water in seldom-used showers weekly to keep P-traps full.
- Use a hair catcher to stop clogs before they start.
- Clean your drain monthly with baking soda and vinegar.
- Use a good exhaust fan or simply open a window during and after showers for proper ventilation.
- Have your pipes professionally inspected every year, especially in older homes.
These simple habits will eliminate shower drain odor before it starts. That way, your bathroom will always smell fresh.
Common Fixing Mistakes for Drain Odors
In an attempt to eliminate a bad odor from the shower, many homeowners unknowingly make the problem worse. Here are the most common mistakes:
- Overusing chemical cleaners: They might seem like a quick fix, but harsh chemicals can eat away at your pipes, leading to bigger headaches (and bills) down the road.
- Improper cleaning: Some people remove the drain cover and poke around with wire hangers or other tools. This can damage the internal parts of the drain system or push clogs further down, exacerbating the issue. The right tools—and knowledge—matter when dealing with plumbing.
- Ignoring bathroom ventilation: When bathrooms don’t have good airflow, moisture sticks around longer—and that’s often what causes the stale, musty smell.
Professional Plumbing Help: When to Call
Sometimes, no matter how many home remedies you try, the smell just won’t go away. If your shower drain ever smells like rotten eggs or if the bad odor keeps coming back, don’t hesitate to get a professional to take a look. Here are signs that it’s time to call Ben’s Plumbing:
- The smell keeps coming back even after multiple cleanings.
- You think there might be mold developing inside the drain or pipes.
- You’ve noticed signs of a leak or visible damage in your plumbing.
- You’re not sure what’s causing the odor and need expert help.
Ben’s Plumbing is are expert at tracking down these smells and fixing the problem so it doesn’t come back. We use cutting-edge diagnostic tools to detect hidden leaks, sewer line damage, and venting problems. Plus, we’re always happy to answer your questions and offer advice tailored to your home’s plumbing system.
A fresher bathroom starts with a trusted team—let the experts at Ben’s Plumbing take care of it.
