Blocked drain in Reading: who is responsible and costs

A blocked drain usually shows itself as a slow sink, a toilet that won't flush away, gurgling plugholes or a bad smell outside. Before you pay anyone, it's worth working out where the blockage is, because if it's in a shared sewer, Thames Water should clear it at no cost to you.

Safety: Drain water can carry sewage. Wear rubber gloves, keep children and pets away, and wash your hands well afterwards. Never climb into a manhole or inspection chamber, and keep any water away from electrics.

Your drain or Thames Water's sewer?

On 1 October 2011, private sewers that connected to the public network were transferred to the water companies. In Reading that's Thames Water. Since then, the split works like this:

• Pipes inside your home, and the drain that serves only your property within your boundary: your responsibility.
• A pipe shared with one or more neighbours that connects to the public sewer: usually Thames Water's.
• The public sewer, usually under the road: Thames Water's.
• If you rent: tell your landlord, who is responsible for keeping drains and sanitation in repair.

How to tell where the blockage is

1. Check whether it's one fitting or several. If only one sink or bath drains slowly, the blockage is usually in that fitting's waste pipe.
2. If the toilet, sinks and outside gully are all slow, the blockage is further down, in the main drain.
3. Lift your inspection chamber cover, if it's easy and safe to lift. If it's full of water, the blockage is downstream. If it's empty, it's between the house and the chamber.
4. Ask your neighbours whether they have problems too. If a shared chamber or several homes are affected, it's likely a shared sewer, so contact Thames Water.
5. If only your home is affected and your chamber is full, the blockage may still be in a shared pipe beyond it. Thames Water can tell you who owns which section.

What you can safely try yourself

• Use a plunger on a slow sink, bath or shower, covering the overflow with a damp cloth.
• Clean out hair from shower and bath wastes.
• Pour hot, not boiling, water and washing-up liquid down a greasy kitchen sink.
• Don't mix drain chemicals, and don't use them in a toilet that's already full, as they can splash back.
• Stop and call a professional if water is backing up outside or sewage is coming up anywhere.

How much does drain unblocking cost in Reading?

These are typical UK ranges checked in November 2026. Price guides put South East drainage prices roughly 15 to 20 percent above the UK average.

• Rodding a simple blockage: typically £75 to £180.
• High-pressure jetting: typically £100 to £400, depending on the length and how stubborn the blockage is.
• CCTV drain survey: typically £90 to £350, more for a full written report.
• Cutting out tree roots: typically £200 to £500.
• Patch lining a cracked section without digging: typically £300 to £900.
• Digging up and repairing a drain: typically £600 to £2,500.
• Out of hours call-outs: often add 50 to 100 percent.

When do you need a CCTV drain survey?

If the same drain keeps blocking, smells persist, or there's subsidence or rats near a drain, a camera survey shows what's going on inside the pipe: roots, cracks, collapsed sections or a dip where waste collects. It also helps prove which section is the problem and who is responsible. Many buyers also get a survey before purchasing an older home.

How to prevent blocked drains

• Never flush wipes, even those labelled flushable, or sanitary products and cotton buds.
• Let cooking fat cool and put it in the bin, not the sink.
• Fit hair catchers in showers and baths.
• Keep outside gullies clear of leaves.
• Get a drain checked if you notice gurgling or slow draining, before it fully blocks.