Why Does My Bathroom Drain Smell?

Why Does My Bathroom Drain Smell?

Every time you walk into the bathroom, you wrinkle your nose because you feel the smell of sewage coming from the drains. You know they’re the source of the stench, but you cannot tell for sure where the origin is. While you’re aware that your bathroom is sometimes the home for unfortunate odours, this one feels out of place. 

Your first instinct is to lean closer to the shower drain, sink, or toilet to try to identify the origin of the odour that makes it unpleasant to have a proper bath or wash your teeth in the morning. You pour some cleaner into the sink, shower, bathtub, and toilet and give them a scrub, even if you sanitise them weekly. For a couple of minutes, you feel how the fragrance of the cleaner temporarily masks the unfortunate smell, and you leave the bathroom happy that you managed to get rid of it. But when you come back later, you catch the same whiff, and all you want to do is close the door and get as far away as possible from the bathroom. 

As the days pass, the smell becomes unbearable, and no amount of fanning, scrubbing or spraying air freshener can resolve it. Why does this happen? 

Several factors can cause the bathroom drains to smell, and it can be challenging to pinpoint its source from a first look. Besides the bad odour, the methane in the sewer gas can become flammable in large quantities, and it’s dangerous to breathe it. 

Possible Causes of The Sewer Smell

Bacteria build-up

The bad odour can come from gunk build-up or bacteria. Only think about the things that go down the bathroom drains (dirt, hair, food). All these things can get stuck in the pipes and trigger a smell. Smells usually accompany a blockage, so if you feel a foul odour in the bathroom, it’s the moment to clean the drains. Clearing the drainage system may get rid of the smell. Contact a professional plumber to check the drains and clean them properly. 

Mould growth

As you may know, there are many damp and dark areas in the bathroom. They create the perfect environment for mould and mildew to grow and thrive because it prevents wet areas with low light. Mould has a nasty odour that doesn’t dissipate until you remove all the fungus. If you feel a bad odour, carefully inspect the bathroom for mould and mildew because it may grow under the tub or sink or between the drain cover. When you check for mould, take all furniture and decorations out of the bathroom, remove the drain cover, and inspect every item. Mould thrives in small places hidden from sight because you don’t usually clean and dry them properly. Even if you don’t find any fungus-infected surfaces, spray the tub, sink, toilet, and drain pipes with a mould and mildew remover. Use the same solution to clean the other items you use in the bathroom. 

Dry P-trap

When you have more than one bathroom in the house, you may notice a funny smell when you enter the one you use the less. Because the drain hasn’t been used recently, you have to run water and refill the P-trap to clear away the smell. Drain lines have a goose-necked area of pipe that has a crucial role in blocking sewer gas from getting out of the drainage system. It’s easy to spot the P-trap. Look under the sink, and you’ll notice a curved section of the pipe. Plumbers refer to it as the P-trap, even if sometimes it has a u-shaped form rather than a p-one. When you don’t use the bathroom for a long time, the water in the trap evaporates and allows the gas and smell from the pipes to enter the house. 

To prevent the water from the P-trap from drying out, ensure that you run water in all taps at least once a month. 

Dry floor-waste drain

Bathrooms in Australia have floor waste placed in the middle of the room. If your house is older, the floor waste has a round shape with a chrome grate you can quickly notice in the middle of the bathroom. But if you have a modern house, the shower waste is the main grated waste in the room and has a wet room design. 

All floor and shower wastes have water seals at the bottom to stop sewer gases from getting inside the house. When you use the bathroom regularly, the floor waste drain is always wet, and you can check the level of water if you use a flashlight to look down the drain. 

However, if you don’t usually use the bathroom, you may find no water when you look down the grate. This issue is often associated with a horrid smell. The quickest fix is to pour water down the drain to reform a water seal at the bottom of the trap and prevent the odour from entering the bathroom. When the floor waste is dry, the smell is so strong it gives the impression that something is dead in the plumbing system. If you cannot get the seal back by pouring down water in the drain, call a licensed plumber to investigate the problem. 

Sometimes you feel a foul odour even when there is a water seal in the floor-waste drain. Bacteria or sediment sitting at the bottom of the trap can trigger it. The hair, soaps, shampoos, and bodily fluids that get into the drains can accumulate and emit the smell. Pouring a drain-cleaning solution can remove the sediment and bacteria from the bottom of the drain and eliminate the smell. 

Deteriorated toilet waste collar

Usually, the toilet isn’t the cause of smells in the bathroom, but it can trigger a mighty odour if the rubber seal connecting the water pipe to the toilet pan has deteriorated. The rubber seal on the toilet waste collar can become loose or get dry with age and experience wear and tear when the toilet is used regularly. When a large family uses the same bathroom for a prolonged period, the toilet waste collar deteriorates more rapidly. 

If you think this causes the bathroom drain smell, call your local licensed plumber to check, remove (if necessary), and replace the toilet pan with a new seal. In some instances, the plumber doesn’t find it necessary to replace the toilet pan, so they only use a sealant to reseal it and prevent the bad odours from entering your house. They may also recommend installing a wall-faced toilet pan where the pan conceals the pan collar because it can prevent the sewer gases from reaching the bathroom when the collar deteriorates. 

Inadequate ventilation

This isn’t a plumbing issue, but you should consider it when you cannot get rid of the bathroom smell. Your bathroom contains moisture, and as any other humid environment, it can cause mould to grow. Proper ventilation is essential for airflow in the bathroom because it removes the moisture that encourages smelly mould to grow and thrive. If you have a window, leave it open after you take a shower to ensure that the steam is able to escape the room. 

Supposing you plan a bathroom remodel in the near future, consider installing louvre windows at the top of the wall because the steam rises towards the ceiling, and the windows can ventilate it out of the bathroom. 

If you don’t have a window, install an exhaust fan to ventilate the bathroom and prevent mildew and mould growth. 

Clog in the sewer line

No one likes the smell of human waste; it’s highly unpleasant and can pose a risk to your health. If you feel a sewage smell in the bathroom, it may be a sign of a clog in the sewer line. When there is a clog in the pipes, the waste cannot pass it and remains in the drains. Sometimes it even gets back into the shower, sink, or toilet drain. If this happens, you should act swiftly and call a professional plumber to handle the situation. The longer you wait to remove the clog from the pipe, the more chances are for the sewer to spill the waste into your house. It’s safer to hire an experienced plumber to seek it out and remove it before it causes damage. 

Why do clogs form in the drains? Multiple factors can cause a blockage, and sometimes removing it isn’t easy. The most common causes of clogs in the sewer line are:

– Flushable baby wipes

– Soap and hair scum

– Foreign objects

– Tree roots obstructing or damaging the pipes

Basin overflow

Did you know that the round hole located at the front or back of the basin is called an overflow? This accessory prevents the basin from overflowing in case you leave the tap on or overfill the basin. When the water rises in the basin, it overflows through the hole and into the drains. But in time, the overflow hole can build up with dirt, dust, cleaning products and other forms of debris and smell a little funky. 

Signs Your Bathroom Drains Require Repair or Maintenance

Drains and sewers are key components of any building, and a functioning plumbing system is essential to everyday modern life. However, its importance will often become apparent only when it malfunctions, like when it causes a drain smell in the bathroom. The maintenance and upkeep are the driving force of any plumbing system because they can avert water flooding problems and foul odours and help prevent costly repairs and other issues that can trigger further problems. 

Like all the other household systems, the drain and sewer show warning signs before a major problem arises. They are indications that the things may malfunction, and it’s essential to recognise them before they transform into a plumbing emergency. 

Here is a list of drain and sewer signs you shouldn’t ignore. 

Odour – any foul smell in the bathroom is a sign of a severe plumbing issue, and you should handle it ASAP. You shouldn’t be able to smell the odours from the sewage when you take a shower, brush your teeth in the morning, or relax in the bathtub at night. In the event of a bad smell, contact a professional to assess the situation and solve the issue. 

Flooding – this is an obvious sign of a serious plumbing malfunction, and you cannot ignore it. Even if it usually occurs in a room with a malfunctioning drain, it can also appear in the basement because it’s the lowest part of the building. When the water floods a room you don’t regularly visit, you can easily miss the sign until it escalates into a bigger issue. Still-standing water in the basement can cause damage to the house foundation and promote mould growth. The moment you notice flooding, call the experts to identify the source and fix the plumbing system. 

Noises – there’s no reason for the plumbing system to make any kind of noise. Strange noises like gurgling in the drains can indicate a blockage, and you should repair it immediately. 

Water quality – you use the water that runs through the plumbing system daily. Whether you use it for washing your clothes or bathing yourself, it should always be at its best. A problem with the pipes and drains can contaminate the water supply in the bathroom and the other rooms of the house. The water running through the drain system should be odourless and clean at all times, and if you notice any change, hire a plumbing technician to check it and identify the cause. 

Clogs in the drain – clogs can occur at any time, no matter the condition or age of the pipes. Multiple clogs can trigger severe problems, as we already mentioned, and you should have them fixed immediately. Clogs are often accompanied by slow drainage, toilets that overflow, and other similar signs. 

Leave the bathroom drain smells to the professionals

Plumbing problems are always a significant disruption and inconvenience to your daily routine. Leave them to professionals to ensure they’re completely fixed. 

Need a Sydney Plumber? Contact MPJ Plumbing Group Today