Why Does My Bathroom Smell Like Sewage? Causes and Fixes

Detecting the bad smell and wondering why does my bathroom smell like sewage? A bathroom is a place in your home that needs extra care and maintenance. And even though you may go to extreme lengths to keep your bathroom clean and fresh, some things are out of your reach.

One such problem is the smell of sewage emanating from your bathroom. Besides the foul smell, the gas from your sewer also poses health risks and must be fixed as early as possible. To help you understand what may be the reason behind your foul-smelling bathroom, here are the 8 most common reasons behind it and the solutions.

Why Does My Bathroom Smell Like Sewage? 8 Reasons

Here are the 8 most common reasons behind sewage smell in the bathroom and their fixes:

1. Dry P-Trap

If you don’t know what a P-Trap is, it is the U-shaped pipe that connects your sink drain to the larger wastewater pipe. The shape is designed so that water is retained in the pipe, which prevents sewer smells from entering the bathroom.

If you have a guest bathroom or some bathroom that you do not use often, the water in the P-Trap evaporates, allowing a free passage of sewage gasses to your bathroom.

Fix: All you have to do is restore the water in the P-Trap. Open the sink tap and let it run for a few minutes. If you suspect clogging, add a little baking soda.

2. Clogged Shower Drain

The shower drain gets clogged eventually. Hair, dead skin, shower gel, and pieces of soap get trapped in the drain, clogging it. Also, it is easy to conclude that the horrible smell is from the shower drain, as it is accompanied by minor flooding during showering.

Fix: The fix is to remove the debris and unclog the drain. But it can get a bit messy. Remove the drain cover and remove as much debris as possible. If you have an auger or plumber’s snake at hand, you can use that too. Now, pour a mixture of vinegar and boiling water, followed by 1 cup of baking soda, and let it sit for around 2 hours. Flush it with hot water.

3. Damaged Toilet

Your toilet could get damaged due to regular wear and tear and becomes a source of sewage gas in your bathroom. To confirm, check the wax sealing at the base of your toilet. If it has come loose and there are tiny gaps, it is the culprit behind the nasty smell in your bathroom.

Also, like the P-Trap of the sink, the P-trap of the toilet may also have reduced water level. This could be due to cracks in the toilet bowl, which results in water leakage or water evaporation if the bathroom is not used often.

Fix: If the issue is with the P-Trap, follow the same procedure as with the dry P-Trap of the sink. If the issue is with a broken seal, use a sealant to re-caulk or reseal the gaps.

But if the issue is a major leak, you will need to get the issue professionally checked and fixed.

4. Broken, Clogged, or Poorly Installed Vent Pipes

Issues with the vent pipe lead to sewer gasses escaping to the bathroom. Vent issues are also often accompanied by gurgling or bubbling sounds from the toilet. This noise is a result of the gasses making their way into your bathroom.

It might be the result of a variety of issues, such as breakage, clogging, or poor vent pipe installation.

Fix: The issue is quite serious and must be left in the hands of professionals, but if you want, you can check the vent for possible blockages and remove them.

5. Clogged Drains

Just like your shower drain, your other drains can also suffer from blockage. While drains are not easily blocked, and it will take much more time to block a drain than a shower drain, it is still possible.

Fix: Follow the same unclogging routine mentioned for the clogged shower drain.

6. Bacteria Built Up

A sewer system is a moist, ventilated area that perfectly supports the growth of bacteria. These bacteria can colonize to form complex films and layers, which are harmful to health and can be very difficult to deal with.

Bacterial colonies have specific smells, and as their population increases beyond a point, those smells become detectable to the human nose.

Fix: You’ll need antibacterial agents like bleach to get rid of the bacteria. It will not only eliminate the bacteria but also mask the foul smell. However, it will take repeated cleaning and flushing to completely remove the colonies. It is always best to keep the toilet clean, even the hard-to-reach spots.

7. Sewer Backup

If the sewer smell arises immediately after heavy rainfall, the most probable cause is sewer backup. When there is heavy rainfall, there is too much pressure on the city’s sewer system. The system could overfill, resulting in sewer backflow that goes into individual sewer lines. This results in sewage backing up into homes.

But when the pressure is not high enough to push the sewage into your home, it will still be high enough to push sewage gasses trapped in the lines into your home.

Fix: You can do nothing but wait for the sewer to flow back. However, you can install a backflow valve as a precautionary measure to prevent sewage water from re-entering your home.

8. Full Septic Tank

If you are not connected to the municipal sewer system, you probably have a septic tank. If so, sewage smells in your bathroom are an indication of a full tank or leach field.

Your toilet will make bubbling and gurgling noises in addition to emitting an unpleasant odor, and flushing will be difficult.

Fix: The solution to your problem is pretty straightforward — drain it. However, to avoid emergency drainage, it is better to perform regular drainage.