Washbasin unblocking

What makes a washbasin block up

By washbasin we mean the basin in the bathroom, the small cloakroom basin in the toilet and the sink in the utility room or garage. They all have one thing in common: a narrow waste pipe. For a bathroom washbasin it's usually 32 millimetres, and the trap directly beneath the basin has tight bends. After the trap, the pipe disappears into the wall, heading for the soil stack or a waste pipe it shares with the shower or bath.

Hair, soap and toothpaste

Loose hairs aren't a problem in themselves, but they catch on the plug and in the trap. Soap residue and toothpaste stick to them, and together they form a grey, felt-like mass. Shaving stubble, make-up residue and cotton pads make it worse. Because only a little water runs through at a time when you wash your hands or brush your teeth, that layer never washes away on its own.

Plug and overflow

Many washbasins have a click-clack plug: you press it to open or close it. Underneath that plug is a spring mechanism that hair wraps itself around. The overflow, the opening near the top of the basin, is worth checking too. The channel behind it is rarely flushed through and becomes coated with a slimy layer that starts to smell.

Cloakroom basin and utility room

A cloakroom basin has a small bowl and a compact trap, so soap residue builds up quickly. In a utility room or garage we see very different causes: sand from mop water, paint from brushes being rinsed out, and leftover plaster or tile adhesive. These set hard in the trap and the pipe and won't budge with a plunger.

In a utility room, the washing machine often drains into the same waste pipe as the utility sink. Fluff, hair and detergent residue then end up in the trap. If the washing machine's drain is blocked, the programme stops halfway with an error message, or the sink next to it fills up as soon as the machine pumps out. Clean the machine's pump filter first; if the problem persists, the blockage is probably in the pipe.

Blocked washbasin, or is the problem further down?

If only the washbasin is draining slowly, the dirt is almost always in the plug, the trap or the first section of pipe in the wall. If water comes up in the shower or bath while you're using the washbasin, they share a pipe and the blockage is beyond the point where they meet. If the washbasin gurgles when someone flushes the toilet, the soil stack may not be vented properly, or there may be a partial blockage lower down in the building. Telling these situations apart shows us where to start unblocking the basin.

If there's a musty smell but the basin drains normally, the cause is usually different: a dirty overflow, or a trap whose water seal has dried out, for example in a guest bathroom that hasn't been used for weeks.

Cleaning the trap and other safe steps

You can clear most washbasin blockages yourself by cleaning the trap. Here's how:

1. Put a bucket or bowl under the trap and lay a towel on the bottom of the cupboard.
2. Undo the nuts by hand. With a bottle trap, you only need to unscrew the bottom section.
3. Remove the hair and deposits and rinse the parts clean in the bucket, not in the washbasin itself.
4. Check that the rubber seals are intact and properly seated.
5. Put everything back together hand-tight and run the tap for a minute to check for leaks.

If the problem is mainly in the plug, use a barbed plastic hair-removal strip to pull the hair out. A plunger can help too, as long as you block the overflow with a wet cloth first. Otherwise the pressure escapes through the overflow and has no effect on the waste pipe.

Steer clear of caustic drain cleaners

Drain cleaners containing caustic soda or acid can damage metal parts and rubber washers, and they only partly dissolve a clump of hair. If the product doesn't work, you're left with a basin full of corrosive water that runs over your hands when you unscrew the trap. That's why we advise against them.

When to leave it to us

Call us if:

• the water still won't drain after you've cleaned the trap;
• water comes up in the shower or bath as the washbasin empties;
• the trap is stuck or looks as if it might break when you try to unscrew it;
• plaster, paint or tile adhesive has set hard in the waste pipe.

How our engineers unblock a washbasin

If the blockage is beyond the trap, the engineer works through the wall connection, not through the plughole. That way the drain snake goes straight into the pipe without first having to get round the bends of the trap. For a short pipe in the wall, a thin hand-held drain snake is usually enough. If the waste pipe is longer, or joins the one from the shower or bath, the engineer uses an electric drain machine with a coil sized to the pipe.

In older homes, washbasins are sometimes connected to a long horizontal pipe with little fall. Deposits build up along its full length, so it's better to flush the pipe through thoroughly once it has been unblocked. If the shower has the same problem, see our page on shower drain unblocking. For kitchens, where grease is the main culprit, see kitchen sink unblocking.

Once the basin is unblocked, the engineer fills it up to the overflow and lets it empty in one go, so you can see for yourself that it's draining at full capacity again.

Costs, emergencies and when it can wait

We charge from €129 to unblock a washbasin, call-out charge not included. In the evening, at night, at weekends and on public holidays the out-of-hours rate applies. If several drains need doing at once, or a long shared pipe needs cleaning, you can ask for a quote. We'll give you a price estimate over the phone before the engineer sets off.

A slow washbasin is rarely an emergency. If you have another washbasin or can use the kitchen sink, it can often wait until the next working day. It's a different matter if water is coming up in the shower or bath, or if waste water is about to spill over the rim. In that case we'll come out, even outside office hours, and the engineer is usually with you within the hour. We're available 24 hours a day to help you weigh it up.

Keeping your washbasin clear

A few everyday habits help:

• Fit a strainer or hair catcher in the plughole and empty it every week.
• Run some warm water after brushing your teeth or shaving.
• Put cotton pads, hair from your brush and razor blades in the bin, not in the basin.
• Clean the trap as soon as you notice the water draining more slowly.
• Rinse paintbrushes and tools covered in plaster or tile adhesive in a bucket first and let the residue settle.

Stick to these habits and you'll rarely need to have your washbasin unblocked.

In your area

We unblock washbasins in places such as Almere, Amersfoort, Arnhem and Zoetermeer. The page listing cities in our service area shows which places have a page of their own, but we're just as happy to come out anywhere else in the Netherlands. To find out more about how our drain unblocking service works, see that page.

Washbasin blocked and can't clear it yourself? Call 085 333 4698 for a price estimate and an engineer in your area.