Sometimes, even after you have scrubbed your sink, blitzed your bathtub and cleaned your counters, nasty smells can still linger in and around your bathroom and kitchen areas.
On closer examination, the smell might be coming from the plughole in your sink and it might smell like rotten eggs, or even raw sewage. But what causes that to happen and what can you do about it?
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 this problem.
There are many different types waste traps used in the home, but ultimately, they all serve the same purpose: to prevent sewer gases from re-entering the home.
They are typically found below or within a plumbing fixture within the home, and are shaped in such a way that ensures there is always a small amount of water retained within the trap. The water that remains in the trap acts as a shield to block sewer gases from entering the home from the foul water pipes your system is connected to.
Traps only work if they are sufficiently vented – this equalises the pressure within the pipes to allow sewer gases to escape safely.
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 water you’ve used – foul water, or waste water – leaves your household and enters the main drainage system in your area via foul water pipes and drains. Each foul drain pipe takes water into a manhole or inspection chamber before entering the sewer system.
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
There are typically four common causes of foul smells from plugholes in the home:
Waste disposal units and macerators are devices that are designed to grind food waste into pulp for ease of disposal. Unfortunately, they’re bad for our sewers because by grinding up fatty foods, it makes it easier to rinse down our sinks and stick to inside of pipes and our sewer walls. It can cause blockages, flooding and 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 caught on the lining of your sink drainage system – either in the the pipes themselves, in waste traps or in grease traps. When FOG and these other items get caught in traps or build up in pipes, they can rot, decay and cause that foul smell.
Particularly in the bathroom, your sink, bath or shower may become blocked – and it’s usually because of hair you shed when 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 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’s plenty of things you can try before thinking about calling out the professionals.
If there’s evidence of grease deposits, we would strongly recommend that the drains are de-scaled professionally via 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:
Read our full blog post on the simple steps you can take to stop your drains from smelling.