A kitchen sink that keeps blocking usually has a build-up somewhere in its trap or waste pipe. Food scraps, fats and grease are often the main cause, and they tend to collect in the same spots again and again. Knowing where the problem starts can help you stop it coming back.
Food Scraps and Grease in the Sink Waste
Small bits of food slip down the plughole every day. Rice, pasta, coffee grounds and vegetable peelings can swell or clump together, catching on the inside of the pipe.
Fats, oils and grease are a bigger problem. They may look like liquid when hot, but they cool and harden inside the pipe, creating a sticky lining that traps more food. Thames Water explains that fats, oils and grease cause drain blockages, which is why it helps to wipe greasy pans with kitchen roll and put the waste in the bin.
The Sink Trap Is a Common Trouble Spot
Under your kitchen sink is a curved or bottle-shaped trap. It holds a little water to stop smells coming up from the drain, but its shape also makes it a natural place for debris to settle.
If the trap has not been cleaned for a long time, it can slowly fill with sludge. The sink may drain more slowly each week until it stops altogether. Clearing it may help for a while, but if the build-up is further along the pipe, the blockage can return quickly.
Waste Pipe Layout and Poor Fall
The pipe that runs from the trap to the outside drain needs a gentle downward slope, known as the fall. If the fall is too shallow, or the pipe dips in places, water moves slowly and food settles instead of being carried away.
Long pipe runs, tight bends and narrow sections can also restrict the flow. Some kitchens have had changes over the years, with pipes moved to fit new units or appliances. These changes can sometimes leave awkward joints where waste tends to catch.
When Repeat Blockages Need a Closer Look
One blocked sink now and then is common. A sink that blocks every few weeks may point to something more than daily habits, such as a hardened grease lining, a poor fall or a damaged section of pipe. It is best not to rely on harsh chemical drain cleaners, as they may not clear the real cause and can be unpleasant to handle.
A plumber can check the trap, the waste pipe and the way it is laid out to find where the problem is building up. If your sink is blocking again and again, getting blocked sink clearance from a local plumber can help get things moving and show what is behind it.
If your kitchen sink in Swindon keeps blocking and you would like it looked at, Emergency Plumber Swindon is happy to help. Call us on 01793 569521 for friendly advice.