If there's biofilm buildup on the fixtures, pipes, or drains, this is most likely caused by bacteria. It's gross and smells like rotten eggs. Surprisingly, this happens because of hair that's washed down the drains every time someone takes a shower. Bacteria like to feed on the particles and debris that hair attracts.
Just in case, I advise scrubbing the whole thing down with baking soda and then wiping it down with white vinegar. Then, pour baking soda down the drain and let it sit for a few hours; pour some vinegar down and let it foam, then follow up with hot water (this also works well for minor to moderate clogs).
Build-up Of Biofilm
Biofilm is a thin, slimy layer of bacteria that can grow from all the water, soap, shampoos, and body oils that go down the drain. This can then accumulate inside the pipes, causing your shower drain to smell like rotten eggs.
To do so, pour a little dry baking soda into the affected drain. Then, slowly add vinegar until all the baking soda reacts. Keep running small amounts of vinegar into the drain until you don't hear any bubbling and your drains smell fresh and clean.
Once you unclog your drain, mix one part bleach with one part water and pour it down the drain to kill the odor-causing bacteria. If you do this and it still smells, it might be time to call a plumber. You could have a faulty P-trap, which prevents sewer gas from entering your bathroom.
P-traps, named after their shape, contain a u-shaped bend that filters wastewater as it enters a plumbing system. The trap is connected to a sink, bathtub, and shower with a J-bend on one end and exits into your drainage system. The J-bend is the section of the p-trap that resembles the letter J.
A common cause of a bad smell is simply bacteria. This usually occurs in indoor bathroom drains and sinks, as bacteria can come from hair, dirt or products that have gone into the drain. There are ways to prevent this build-up including bathroom drain traps.
Baking soda is abrasive, which, when used in large quantities, will cause the drain more damage. Additionally, the acidic nature of vinegar can eat away rubber and metal, damaging the plumbing. As these products break down the pipe and connectors in the plumbing in your home, it will cause more clogs over time.
Is your P-trap working properly? If you detect any foul odors near the P-trap that remind you of a smell similar to rotten eggs, then it means that there is hydrogen sulfide present. This, and other harmful gases, bacteria, and viruses, can get into the house if your plumbing trap has malfunctioned.
Infrequently used drains and sinks will dry out, allowing these odors (usually a rotten egg, sewer, or occasionally gas, chemical or solvent odor) to escape. The solution to this problem is simple—run water in all sinks periodically or pour water down floor drains from time to time (once a month is recommended).
You can check the p-trap yourself rather easily. First, look into the drain with a flashlight. You should be able to see some water. If you do not see water, the p-trap water level is likely too low.
Hydrogen sulfide gas (H2S) can give water a “rotten egg” taste or odor. This gas can occur in wells anywhere and be: Naturally occurring - a result of decay and chemical reactions with soil and rocks. Produced by certain “sulfur bacteria” in the groundwater, well, or plumbing system.
In conclusion, sewage gasses, biofilm accumulation, bacterial development, and P-trap drying up can all be responsible for the foul odour emanating from a shower drain that appears to be unclogged.
You should try to clean the shower trap every few months, which is straightforward job to do: Remove the shower waste cover. Some systems are slot only, but if your system is secured with screws, be sure to use the appropriate screwdriver before attempting to remove any component.
To use bleach to kill odor-causing bacteria, first, fill your sink with hot water. Then, add about one cup of regular household bleach to the sink. After you've added the bleach, allow the sink to drain. Repeat the process until the drain smells more like bleach than anything else.
Pouring boiling water is quite risky as it might lead to a steam burn or scalding. Another thing to keep in mind is what type of material you are pouring in into. If you have a porcelain sink, it is likely to crack due to the heat. All in all, pouring boiling water down your drain will only cause issues down the road.
If you put too much baking soda down a drain onto a clog, it can sit on the clog and become a solid mass as it is subjected to more and more water. This will make the block worse and even harder to remove.
Clogged Drains
A clogged drain can lead to stagnant water and a buildup of waste materials, creating a breeding ground for bacteria that produce foul odors. If your bathroom sink smells like sewage, a clogged drain could be the culprit. Solution: Use a plunger or a drain snake to clear minor clogs.
Another option is to pour baking soda into the drain, then add vinegar and cover the drain with a plug to allow the vinegar and baking soda reaction to clear the clogged drain. This method will also disinfect and deodorize the drainage pipe to get rid of the rotten egg smell.
Slowly pour about a gallon of water into the drain. This will refill the trap and recreate the seal to block sewer gases. For long-term prevention, consider adding a small amount of mineral oil on top of the water in the P-trap.
You might be wondering: Should there be water in the trap shower? You might be surprised, but the answer is yes. Shower waste traps are designed in a way to always have a little water sitting in the shower tray in order to prevent any malodorous gasses from the sewer to enter your bathroom.
A blocked p-trap will cause water backflow to occur. The first sign that your p-trap is clogged is when the water in your sink takes longer than average to flow down the sink.