Blocked sewer? 24/7 emergency service

How a sewer slowly silts up

A sewer rarely blocks all of a sudden. Usually a layer of grease, soap residue and silt builds up inside the pipe over months. Then one day, one wipe or wad of paper too many gets caught, and the whole pipe backs up.

What goes down the toilet and the kitchen sink

Most blockages start inside the house. Wet wipes barely break down in the sewer, even when the packet says 'flushable'. The same goes for sanitary towels, cotton buds, kitchen roll and cat litter.

The kitchen adds grease, which sets in the cold pipe and traps everything that floats past. And after a renovation we regularly find leftover tile adhesive, plaster or cement that someone casually rinsed down the drain.

Roots, subsidence and old pipes

In older properties, the cause often lies in the pipe itself. Tree roots go looking for moisture and grow into the pipe through a small crack or a leaking joint.

On soft ground, a section of sewer can sag, leaving a dip where dirt settles and stays. In old clay or concrete pipes, the joints shift or crack over time. Jetting alone won't fix a problem like that for good.

Blocked sewer, or just one drain?

Not every slow drain means the sewer is blocked. If only the washbasin is slow to empty, the blockage is probably in the trap or just behind it, and having that one drain cleared will be enough.

If the sewer is blocked, several drains are affected at once, starting with the lowest: the shower drain on the ground floor or the toilet in a basement flat. If someone flushes upstairs and water comes up downstairs, you've got your answer.

Other signs are a sewer smell in the house or garden, a toilet that gurgles while the washing machine is pumping out, and an inspection chamber in the garden where the water is higher than usual. After a heavy downpour the public sewer can fill up for a while. If the problems carry on in dry weather too, the cause is almost certainly in your own pipe. If only the toilet overflows and everything else works normally, see toilet unblocking.

What you can safely do yourself

Unblocking a sewer yourself almost never works, because the blockage is usually metres away, underground. What you can do is limit the damage while the plumber is on the way. This is the advice we give everyone who calls:

1. Stop flushing, showering, washing up and doing laundry. Every litre you send down the drain comes back up at the lowest point in the house.
2. Lift the cover of the inspection chamber at the property boundary, if there is one and the cover is light enough. If the chamber is full, the blockage is towards the street; if it's empty, it's somewhere between your house and the chamber.
3. Put towels around the drain or toilet where the water is coming up, and move anything that could get wet up off the floor.
4. If you live in a block of flats, let the VvE (owners' association) or the managing agent know what's happening. Everything the neighbours upstairs flush away ends up on the ground floor.

Why we advise against chemical drain cleaners

A bottle of drain cleaner containing caustic soda or sulphuric acid looks like a quick fix, but with a blocked sewer it doesn't even reach the blockage. What you're left with is a corrosive liquid sitting in your shower drain or toilet. It can splash, it attacks rubber seals and older pipes, and it's dangerous for the plumber who has to work on it afterwards. And never mix different products, as that can release harmful fumes.

Time to stop and call

If sewage is getting into your home, there's a strong sewer smell or the inspection chamber is full to the brim, call 085 115 0249 straight away. Never climb down into a chamber yourself, and don't put your face over an open sewer chamber: harmful gases can build up inside.

You're also better off leaving a short drain snake from the DIY shop on the shelf. It won't reach far enough and can get stuck in the pipe.

How we approach sewer unblocking

Sewer unblocking starts with finding exactly where the problem is. A wad of wipes calls for a different approach from a sagging pipe full of roots, so the plumber investigates first and only then gets to work.

Clearing with a drain snake or machine

The plumber feeds a drain snake or an electric drain machine in through the inspection chamber or an access fitting in the crawl space. The rotating head breaks up the blockage or pulls it back out. That often ends the worst of it quickly, and you can flush again.

High-pressure jetting for a clean pipe

Punching a hole through the blockage doesn't give you a clean pipe. That's why we usually jet the sewer at high pressure as well: a hose with a nozzle is pushed into the pipe and blasts grease, silt and loosened debris towards the main sewer. Cleaning the sewer this way also strips the build-up from the pipe walls, so the next blockage isn't already halfway there.

Drain camera inspection: look first, then decide

If the blockage keeps coming back, or the plumber suspects a break or root intrusion, a small camera on a push rod goes into the pipe. On a screen you can see for yourself what the inside of the pipe looks like: whether there's a sagging section, a crack or a tangle of roots, and how many metres from the chamber it is. That way you can have the pipe repaired in exactly the right place instead of digging up half the garden.

What does sewer unblocking cost?

A simple unblocking, where the plumber clears the blockage with a drain snake or machine, costs from €89. The call-out charge is extra and isn't included in that starting price. If you need your sewer unblocked in the evening, at night, at the weekend or on a public holiday, an out-of-hours rate applies. We'll give you a price estimate for your situation over the phone, before the plumber sets off.

Larger jobs are a different matter, such as cleaning a long stretch of sewer, an extensive camera inspection or repairing a broken section of pipe. For those, you can ask for a quote. The plumber first assesses the situation and explains what's needed, and then you decide whether the work goes ahead.

After an overflow: cleaning up, neighbours and insurance

An overflowing sewer is more than a dirty job. Sewage contains bacteria, so wear gloves, clean floors and skirting boards thoroughly, and throw away any soaked rugs and cardboard boxes. Open the windows and let the room dry out properly.

Take photos of the damage before you start clearing up. Once the job is done, the plumber will explain what caused the problem; you'll need that information if you report the damage to your insurer. Whether water damage is covered depends on your policy.

If you rent your home or live in a flat, tell your landlord or the VvE as well. A building's drains usually aren't down to any one resident, and in many municipalities the section between the property boundary and the main sewer is the municipality's job.

How to keep your sewer clear

Most of the maintenance comes down to what you flush away:

• Put wipes, sanitary towels and cotton buds in the bin, even if the packet says they can go down the toilet.
• Let deep-frying and roasting fat cool, then put it in the general waste or take it to a collection point rather than pouring it down the sink.
• Never rinse building waste such as tile adhesive, plaster or cement slurry down the drain.
• Don't plant trees or large shrubs close to the sewer pipe in your garden.

If you live in an older property and have had trouble with roots or subsidence before, having the pipe jetted regularly can prevent a repeat. After the job, the plumber will tell you whether that makes sense in your situation.

A full sewer at night? We'll still come out

Sewers don't block at convenient times. It happens on a Sunday evening, in the middle of a birthday party or at three in the morning when someone flushes for the third time. You can always call us for sewer unblocking outside office hours, public holidays included, and the plumber is usually with you within the hour. So if the bathroom and kitchen are out of action, you don't have to wait until Monday.

We help residents in Haarlem, Zwolle, Groningen and Den Bosch, among other places. Live somewhere else in the Netherlands? You can still call us. You'll find a selection of cities, each with notes on local drainage and soil, under our service area. Shower drain already full of dirty water? Call 085 115 0249 and tell us what you can see.