Almost all of us have walked into a bathroom at some point and gone, “Phew, what is that smell?”. Maybe it was after we were gone on vacation for a few days and came back or maybe one day it just hit us like a ton of bricks, but most of us have experienced this.
If you've ever had a smell hit you in the face when you walk into the bathroom, this article is for you.
We will review what a shower drain can smell like, why it smells like mildew, and how to fix it.
What Can A Shower Drain Smell Like?
Dirty shower drains have been described in a variety of different ways. The description difference has a lot to do with what is causing the smell in the first place, be it a broken pipe, sewer clog, etc.
To determine whether your shower drain is the stinky culprit, you may have to get down there and smell it directly.
Nobody wants to do that, but it's the only way to differentiate between your shower drain and your sink drain being responsible.
When you smell it, does it smell like any of the following?
- Wet hair
- Urine
- Mop water
- Skunk
- Sulfur
- Natural gas
- Rotten eggs
- Spoiled milk
- Wet dog
If you can smell anything like this in your drains, there's a definite problem there.
It may be easy to fix by running a cleaner through it, but it may be something more serious, like a broken pipe.
Reasons Shower Drains Smell Like Mildew
Mold and bacteria are ultimately the reasons your drain stinks, but there are a variety of issues that can cause that. Here are the most common ones listed below.
Sewer Line Clog or Break
A sewer line clog, even a partial one, can be made up of a variety of things, such as:
- Soap scum
- Dirt
- Mineral deposits
- Small objects
- Hair
Leaky Pipes
If a pipe leaks, it's likely causing mold on whatever it's leaking onto, especially if the bathroom you're dealing with is an upstairs area or you have a basement.
Eventually, an upstairs bathroom drain leak will become a downstairs ceiling leak, so diagnosing this problem and getting it taken care of as soon as possible is important.
If you don't, you'll have a mold problem in no time.
Dirty, Dry, or Broken P-Traps
The P-trap is the bend in your plumbing drain under your sink, tub, and shower that stops sewer gas from coming back up the pipe into your home.
If you don't use a drain often enough, all of the water in it will eventually dry out. When this happens, your bathroom will begin to smell because there isn't no water to block the gas anymore.
The water can also leak out of the p-trap if broken, so the trap doesn't take as long to dry. Using a drain cleaner once a month should help keep the smell at bay. If the p-trap is broken, you can replace it with one similar to this one on Amazon.
Drain Clog
Your drain could also be partially clogged. However, a clog in your house's plumbing system differs slightly from a clog in your main sewer line. The main line is where all of your drains connect to carry everything out of the house to the city sewer. Any individual drain in your home can be clogged and become smelly, while your main line being clogged will likely make them all smelly.
Biofilm
Biofilm is the result of bacterial and fungal buildup that forms in your plumbing and is the result of not cleaning the drain often enough, even if it doesn't get clogged. It's sticky, gooey, and generally smells nasty.
Is A Smelly Shower Drain Dangerous?
A smelly shower drain can be dangerous if you don't deal with it long-term. If you walk into your bathroom and the smell nearly knocks you down, that's something you need to do something about fairly quickly. Sewer gas, in particular, can contain a few different gases, including:
- Hydrogen sulfide
- Ammonia
- Carbon dioxide
- Methane
You can be fine for a short period smelling these things, but chronic exposure can cause some severe health effects, including:
- Eye irritation
- Dizziness
- Headache
- Drowsiness
- Nervousness
- Poor concentration
- Seizures
- Loss of sense of smell
Sewer gas can also be flammable, another danger to consider when deciding whether the problem is worth fixing.
How To Fix A Smelly Shower Drain
You can fix your drain's odor in a few different ways. Home remedy-type fixes are cheap, but you'll have to step up to more commercial cleaners to get the job done if they don't work.
Vinegar
Vinegar is one of the best deodorizers that there is in the household. Running straight vinegar down your drain can work well, depending on the source of the problem. It kills mold because it has a strong pH level and the fact that it contains between 5 and 8 percent of acetic acid.
Bleach
Bleach is another classic mold and mildew killer that you can use to eliminate drain odors. Be careful with bleach; it's very reactive with other cleaners, and you never want to mix it with anything else. For example, if you use vinegar down your drain to try and kill the odor, under no circumstances use bleach immediately afterward. Vinegar mixed with bleach creates chlorine gas, and this can be deadly.
Enzyme-Based Drain Cleaners
Enzyme-based drain cleaners on Amazon aren't very expensive and can work better than vinegar or bleach. These cleaners contain beneficial bacteria whose enzymes will break down organic particles in your drain, including hair, mold, algae, etc. It essentially “eats” the cause of your drain's odor instead of killing it. These cleaners also don't pose any risk to your plumbing or septic system. If you have a septic tank, enzyme-based drain cleaners can benefit the tank's ecosystem.
Other Causes of Bathroom Odors
If your bathroom stinks, you go through the cleaning process above, and you still have an odor, it may not have been that drain.
Broken Toilet
A broken toilet seal can cause this. When the wax ring for a toilet is broken, everything in your toilet can leak around it and into your subflooring. Bacteria and other nasty things begin to grow; then there's the odor you've been smelling. The only fix for this is to remove the toilet and replace the seal, such as with this highly-rated Danco no-wax seal from Amazon.
Broken or Improperly Installed Vent Pipes
If the vent pipe for your plumbing has a break inside the house, such as the attic, the gas and smells inside it can leak into the house and cause odor. This can also happen if it was improperly installed, but it may not be immediately noticeable.
Full Septic Tank
Full septic tanks can cause sewage backup into the house and cause the whole house to stink. You may notice the smell in one room before you notice it in the others; this is typically the room closest to the tank.
Sewer Backup
This is related to the sewer main clog we mentioned above, but it's like having a full septic tank: your main line is so clogged that sewage is starting to back up into the house. If this is the problem, you will likely know it quickly, as one of the drains in your home will have sewage backing up into it.
Conclusion
There are a variety of causes of bathroom smells, but basic drains are the most common. If you've been through the wringer trying to figure out why the bathroom stinks, it may be time to call a plumber to check it out.
