Who pays for a blocked sewage pipe depends on where the blockage sits. In short, you look after the drain that serves only your home, while the water company looks after most of the larger shared pipes. This guide explains the split and how to find out which side you are on.

Drain or sewer?

A drain carries waste from one property. A sewer collects waste from more than one property, so it is usually the larger pipe. The difference matters because the law treats them differently. A drain that serves only your home, up to the boundary of your property, stays your responsibility. Since 1 October 2011, most shared drains and private sewers outside the property boundary have belonged to the water company, according to government guidance. However, some pipes are still private, so check before you assume.

Private drains

If only your property uses a pipe, it is a private drain. You must pay to clear and repair it. Because the pipe often runs under your garden, the fault is easy to place on your side. You can choose any drainage firm to do the work. Your home insurance may also cover drain faults, so read your policy before you pay. Blocked drains outside: who is responsible explains how to tell where your boundary runs.

Shared pipes and public sewers

A pipe that serves several homes is a sewer, and most of these now belong to the water company. If the blockage sits in one, the water company deals with it. In contrast, a rare private sewer may still be shared among the homes that use it. Who owns which pipe is not always clear, so ask your water company for a drainage plan, because it should know which sewers it looks after.

How to find out where the blockage is

Start by lifting a nearby inspection chamber cover, if you can do so safely. Look for backed-up waste, because it shows which section is full. If the chamber nearest the road is full, the problem may be in a pipe you share. If it is empty, the fault is probably on your own drain. Ask your neighbours too, since a shared blockage usually affects several homes at once. Blocked drain pipe: branch or main run explains how to tell the two apart.

Who pays?

If the fault is on your own drain, you pay. If it sits in a public sewer, the water company pays, and you should tell it straight away. When a pipe is shared privately, the households usually share the cost. Although this can cause disputes, a calm conversation and a camera survey usually settle it. If a neighbour refuses to act, your local council may be able to help, so check with it.

What a blockage means for you

A blockage causes real harm if you ignore it, because waste has nowhere else to go. What problems blocked drains cause lists the risks. Waste can back up into the lowest part of the house, and how to clear a main sewer line explains what the work involves.

Getting the pipe cleared

For a private drain, an engineer can clear it with rods or high-pressure water, and then check it, while jetting blocked drains explains one common method. What it costs to unblock a drain explains what affects the price. If the pipe is cracked, our drain repairs page explains the options, and collapsed drain repair covers the worst cases.

Tenants should tell the landlord about a blocked drain at once, because the landlord usually arranges the repair. If you share a pipe with neighbours, speak to them early. Since the fault may affect all of you, a shared plan is usually quicker and cheaper than a dispute. Keep photos and notes, as they help if you need to ask the water company or your insurer for help.

Preventing future blockages

Most blockages come from what goes down the pipe. Things that get stuck down the drain lists the usual causes, while why keeping your drains clear matters explains why it pays to look after them.

Help in North London

Although we are based in Enfield, we clear blocked drains across the area, and that includes drain unblocking in Potters Bar, drain unblocking in Southgate and drain unblocking in Enfield. We offer a 24/7 emergency call-out, with no call-out fee and a fixed price agreed before work starts. Use the online enquiry form to describe the problem.