Dealing with a foul-smelling sink drain? Sometimes, even after thoroughly cleaning your sink, scrubbing your bathtub, and wiping down your counters, unpleasant smells can still stick around your bathroom and kitchen.
If you take a closer look, you might find that the smell is coming from the plughole in your sink. It could smell like rotten eggs or even raw sewage.
In this article, we unpack what causes bad bathroom and kitchen sink smells and ways to deal with smelly sink drains, such as how to unblock a sink.
Before we discuss the reasons why your sink might smell, it’s important to first understand the parts of the drainage system that are typically involved in preventing sewer gases and odours from travelling back up the drain.
These include:
There are many different types of waste traps used in the home, but ultimately, they all serve the same purpose which is to prevent sewer gases from re-entering the home.
Traps are usually located below or inside plumbing fixtures in your home. They are designed to hold a small amount of water, which creates a barrier that prevents sewer gases from coming back into the house through the drainage system.
To function properly, traps need adequate ventilation. This ventilation helps equalise pressure in the pipes, allowing sewer gases to be safely expelled.
There are numerous types of waste trap that are present in the typical British home, including:
When you flush the toilet, pour dirty dishwater down your kitchen sink, or brush your teeth, the used water (known as wastewater) leaves your home and enters the main drainage system through foul water pipes and drains. Each foul drain pipe takes water into a manhole or inspection chamber before entering the sewer system.
Discover more information about sewer system layouts in our article ‘Blocked sewer drains: Who is responsible?’.
A grease trap is a piece of equipment that is installed to capture fats, oils and grease (FOG) from sink waste to avoid it entering the drains and subsequently the sewage system. They’re usually only found in commercial properties, because they’re legally obliged to ensure FOG doesn’t enter the drainage system. Our article ‘How to dispose of cooking oil’ explains in more detail why FOG shouldnt enter the drainage system.
There are a few common causes of foul smells from plugholes in the home and these are:
Waste disposal units and macerators are devices that grind food waste into a pulp, making it easier to dispose of. However, they can be harmful to our sewer systems. When fatty foods are ground up, they can rinse down sinks and cling to the insides of pipes and sewer walls. This can lead to blockages, flooding, and even rodent infestations.
When plates with leftover food aren’t scraped or cleaned properly before being washed in the sink, the waste can collect in the pipes underneath your sink.
This waste gets captured by the biofilm in your U-bend, and ultimately, ends up blocking your sink and causing that awful smell.
In addition to FOG, which might go down the drain after cooking, the likes of hair, skin cells, toothpaste, shaving foam, food, tea, coffee can find their way down our plugholes and into our pipes.
All of these substances can get trapped in your sink's drainage system, either in the pipes, waste traps, or grease traps. When fats, oils, grease (FOG), and other materials accumulate in these areas, they can rot and decay, leading to unpleasant odors.
When it comes to your bathroom, it's common for the sink, bathtub, or shower to get clogged. This usually happens due to hair that falls out while you wash.
Hair accumulates in your plughole and mixes with shampoo, shower gel, shaving foam and other substances to create congealed masses of hair. It is these masses that get stuck in your plughole and cause your sink to become blocked and smelly.
We mentioned earlier that waste traps retain water to act as a barrier to stop sewer gases entering the home. But sometimes these traps fail.
If the drainage system is not properly vented, it can lead to high pressure in the drains. This can result in:
A low pressure environment can also occur if there is a problem with the venting in the drains. This could lead to:
If you think the problem has been caused by a build-up of FOG in your drainage system, you can attempt to clean your waste traps yourself.
You will need to set aside about 15 minutes or so, and ensure that your sink doesn’t have any water in it.
The process is pretty standard for each type of trap, so you’ll only need these basic household supplies:
Now, reattach the U-bend to your sink. Make sure the fitting is on tightly to avoid any leaks. Boil your kettle and bring it to your sink. Pour it down your freshly cleaned sink for a final cleanse and check to see if there are any leaks. If there are no leaks, the job is complete.
If you think the blockage in your sink is caused by hair, you can attempt to tackle the problem yourself. There are plenty of things you can try to do before you think about calling out the drain unblocking professionals here at Lanes.
Bicarbonate of soda and vinegar.
Mix together about a ⅓ of a cup of baking soda with a ⅓ of a cup of vinegar, then carefully place it down the problematic plughole. It’ll start to fizz and spit, which should remove any hair and grime. Leave it for about an hour or so, and then rinse it out with a kettle of boiling water.
Tweezers
For fast results, and if you’re able to take off your plughole, consider using tweezers. Remove the plughole cover and start grabbing and pulling hair with the tweezers.
Hair removal cream
Traditionally used for health and beauty applications, this cream can be used on your drain to break down hair. Simply empty an entire tube of the cream into your sink, wait for an hour, and then thoroughly rinse your plughole with water to rinse away your blockage.
Plunger
If you have a significant build-up of grime, soap and hair, and you’ve tried our other tips, you might want to try and use a plunger to unblock your sink. Start by creating an airtight seal with your plunger over the plughole, and then, move the plunger up and down. This creates suction, likely moving the hair blockage closer to your plughole, allowing you to fish it out.
If there is evidence of grease deposits, we strongly recommend that the drains be de-scaled professionally using water jetting.
At Lanes, our specialist engineers employ electro-mechanical, high-pressure jetting and vacuumation units to clear tough blockages and ensure your drainage system works as it should in no time at all.
We always say prevention is better than cure when it comes to drainage systems, and this is no exception for your sinks, so don’t wait for a problem to occur before acting.
The most important thing to remember is to avoid putting things down your sink or drains that could cause any sort of blockage. The ‘Main Offenders’ to avoid are:
At Lanes, we’re on hand to help 24/7, 365 days a year. Contact us today to find out how we can help you with your drain blockage.