Causes and Prevention of Blocked drainage

Blocked drains are common in every home. Fat, oil, hair, soap residue, silt, leaves and litter build up inside the pipes. Over time they narrow the pipe and block it, because the layer grows a little with every use.

When water cannot flow, it backs up and overflows. The kitchen sink, wash basin, toilet and bath are the usual places to see it, since they sit at the lowest points. For a fuller list of triggers, see our guide on the common causes of blocked drains.

Causes of Main Line Problems

Sludge build-up. Soap, hair and grime coat the main line, just as they coat a sink. Toilet tissue adds to the mix. Because the layer grows slowly, you may not notice it until the flow slows. A yearly check can catch it early.

Tree roots. Roots push into pipes through small cracks and grow inside. Building work debris can cause trouble too, particularly while you redo a sink or shower. Our guide on what causes a drain blockage covers more.

Grout and tile pieces. Bathroom tiling work can send grout and tile bits down the drain. A scrap of backing material can catch there, and everything behind it backs up. As a result, a small job can leave a large clear-out.

Old or poor pipe design. Older pipes may have bends that trap waste. Furthermore, pipes can age, crack or sag. A blockage that keeps returning often points to this kind of fault.

How to Prevent Blocked Drainage

Dishes. Scrape plates into the bin, not the sink. Fit a strainer over the kitchen and bathroom plugholes, because it stops food, hair and soap lumps. Our guide on how to keep your drain clear of blockage goes further.

Toilets. Flush only toilet paper and human waste. Wipes, nappies and tissues belong in the bin, because they do not break down in water. See the things that get stuck down the drain for a longer list, and read about the problems caused by blocked toilets.

Fat and soap. Pour cooking fat into a container and bin it. However, fat can hide in other places. Some soaps contain fat, so they can also leave a greasy film in the pipe. Flushing hot water through the drains now and then may help to move light residue along.

Regular checks. A little attention goes a long way, since small problems cost little to fix. Read how often drains should be cleaned to set a routine.

If a Blockage Still Forms

Some blockages form even in careful homes. Therefore it helps to know your next step. Our page on what you can do to clear a blocked drain shows the safe options. For a blockage deeper in the system, see how to clear the main sewer line.

A bath that fills with waste is one common sign, although other fixtures can show it too. See bathtub drain backing up for what to check. Our blocked sinks service and blocked drains service handle the rest.

Local Help

While we work across the area, we especially cover drain unblocking in Southgate, drain unblocking in Enfield and blocked drains in Barnet. If you have a blocked drain in London, send the online enquiry form.