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What Causes Blocked Drains?

What Causes Blocked Drains?

Wondering What Causes Blocked Drains?

Drains don’t get blocked overnight. It can take months for a build-up to turn into a blockage, and there’s plenty of warning signs along the way, before you hit the moment of crisis. In this blog the Simply Plumbing team looks at what causes blocked drains in kitchens, bathrooms and outside. We’ll also tell you what the typical symptoms are to watch out for.

Kitchen Drain Blockages

Kitchen Drain Blockages

Kitchen sink blockages are the most common drainage problems that we deal with. Nine times out of ten they’re caused by a build up of grease, fat and foodstuffs that find they’re way into the drain. To avoid blockages, get into the habit of:

  • Scraping plates thoroughly to stop scraps of food making it through the plughole.
  • Using quality washing-up liquids that break down grease and fat.
  • Avoiding pouring oil or fat down the drain. Pour it into a container and throw it away instead.

Symptoms: If you hear gurgling or ‘ticking’ after the water drains it’s a sign there’s a build up that needs clearing. Unpleasant odours tell you that food is trapped in the drain pipe. Slow draining indicates that the drain has a blockage.

Bathroom Blockages

Bathroom Blockages


If your bathroom sink gets blocked it’s most probably due to a build up of hair and soap. Solid soap bars tend to create a scum that clings to the side of the drainpipe and reduces the space for water to pass through. To avoid blockages in the sink or toilet:

  • Use liquid soap, rather than bars of soap.
  • Avoid washing or brushing your your hair over the bathroom sink.
  • Don’t flush wipes, sanitary towels, cotton wool or nappies down the toilet.

Symptoms: If you notice that your toilet flush isn’t so effective as usual, or that the water level in the toilet bowl is higher than usual, it’s a sign that your toilet has a blockage. The primary sign of a blockage in the sink is slow drainage.

Blockages in Outside Drains

Blockages in Outside Drains

Many of the blockages in outside drains are caused by leaves, and garden waste being washed into the drain and clogging it up. To avoid this, make sure that you:


  • Keep the area around your drain swept clear of fallen leaves.
  • Rake up foliage in your garden and clear it away.
  • Avoid tipping any kind of waste down your external drain.

Symptoms: The smell is probably what you’ll notice first as it tends to be particularly pungent with outside drains. You may also notice standing water around the drain, or hear gurgling.

When Should You Call a Plumber?

If you know what the causes of a blocked drain are, and you’re alert to the symptoms, you’ll probably be able to clear the problem early. If, however, the blockage is recurring, or you find that you can’t drain water from your sink, external drain or toilet, call Simply Plumbing to take a look.

We won’t just clear the problem; we’ll make sure that your drains are clean and healthy before we leave. So, you know there won’t be a return of the smells or gurgles. Simply Plumbing is based in Luton and offers plumbing services across South Bedfordshire. If you have an emergency, you can call us any time of the day or night and we’ll be with you promptly.

Knowing what causes blocked drains helps you to avoid them, but if you have a blockage, you should call a plumber to clear it. Simply Plumbing is available 24/7 on 01582 250030.

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