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Sewage Backup & Drain Flooding

Sewage coming up through a drain, toilet or manhole needs dealing with fast. We clear the blockage, empty the flooded chamber and find the cause, 24/7 across Surrey, Sussex, Kent, Hampshire and London.

Servicing and
repair engineers
24/7
call-outs
Clear report
after every visit
Our own vans
and tankers
34 years
in drainage

The problem

Why is sewage coming back up?

Sewage backs up when it has nowhere to go. Most often the drain is blocked downstream: by grease, wipes or other debris, by tree roots, or by a pipe that has cracked or collapsed.

The blockage can be in your own drain or further along a shared sewer. Heavy rain can also overload drains, and a full septic tank, cesspit or holding tank can push waste back towards the house.

We can empty the flooded chamber with our tankers and clear the cause with high pressure jetting, then check the pipe with a CCTV survey.

Out of hours, call our emergency line on 03333 233577, or our main number on 03333 233566.

How we help

What we do about a sewage backup

Which one applies depends on where the blockage is and what is flooded.

Drain unblockingClearing blocked drains and sewers. High pressure jettingWater jets that scour the pipe clear. Jet/vac combination tankersJet the line and pump out the waste in one visit. Flood & groundwater removalPumping out flooded areas. CCTV drain surveysFinding the fault that caused it. Septic tank emptyingWhen a full tank is the cause.

Right now

What to do while you wait

  1. Stop using water

    Don’t flush toilets or run taps, baths, showers or washing machines. More water only adds to the flooding.

  2. Keep people and pets away

    Sewage can carry germs. Keep children and animals out, and wash your hands well if you have touched anything affected.

  3. Stay safe around electrics

    Don’t touch sockets or appliances standing in water. Switch off at the consumer unit only if it is safe to reach.

  4. Don’t use drain chemicals

    They rarely clear a backup and can make the clean-up harder for whoever has to deal with it.

  5. Call us

    Tell us what you can see and where. We’ll explain what happens next.

Why act

A backup won’t clear itself

If sewage is coming up, the drain is not carrying waste away, and it will not recover on its own. Waiting means more contamination of floors, walls and gardens.

If you are insured, check your policy and take photographs before anything is cleaned up.

Signs a backup is starting

  • Gurgling from sinks, baths or toilets
  • Toilets that won’t flush properly
  • Drains that are slow throughout the house
  • A manhole full or overflowing
  • Sewage smells indoors or around the garden
Get a quote

Why Clearmasters

Why choose Clearmasters?

Sewage on your property is distressing, so we aim to keep things simple: stop the flooding, clear the cause, and tell you honestly if the drain needs further work.

Ask us a question

Always on hand

Planned servicing at a time that suits you, and 24/7 call-outs when something goes wrong.

Straight answers

We explain what we found in plain English, and give you honest advice on what needs doing now and what can wait.

Trained engineers

Our engineers hold current confined space entry certificates and work on treatment plants, pump stations and drainage every day.

We tidy up after ourselves

We reinstate your ground and leave the site clean.

What our customers say

9.85/10

Checkatrade

From 135 reviews · Read them
4.9/5

Google

From 71 reviews · Read them

Scores as of October 2026

Read all our reviews

Questions answered

Sewage backup FAQs

Is sewage backing up an emergency?

If sewage is coming into the house or flooding the garden, treat it as one. Stop using water and call us.

Who is responsible when sewage comes up?

It depends where the blockage is. A blockage in a drain serving only your property is usually yours to deal with. Shared drains and pipes outside the boundary have been the water company’s responsibility since October 2011. Our responsibility guide explains more.

Can you attend out of hours?

Yes. We offer 24/7 call-outs. Our emergency line is 03333 233577 and our main number is 03333 233566.

What causes sewage to back up?

Usually a blockage from grease, wipes or roots, or a damaged pipe. Heavy rain, and full septic tanks or cesspits, can also cause it.

Will it happen again?

It can if the cause is not dealt with. A CCTV survey after the drain is clear shows whether there is damage, roots or a build-up that needs fixing.

Got a different question? Call 03333 233566 or send us a message.

Related services

Drain UnblockingClearing the blockage behind the backup. Jet/Vac TankersJetting and pumping out together. CCTV Drain SurveysFind the underlying fault. Flood RemovalPumping out flooded areas.

Fully accredited & compliant

We're independently vetted and certified so you can trust who you're letting onto your site.

SafeContractor

Health & safety pre-qualification accreditation, verifying our processes meet recognised safety standards.

RISQS

Railway Industry Supplier Qualification Scheme — approved to work safely within the rail industry supply chain.

Achilles UVDB

Utilities Vetting Database membership, confirming we meet the utilities sector's supply chain standards.

Trading Standards Approved

Vetted and approved under the local authority's trusted trader scheme for honesty and fair dealing.

NADC Member

Members of the National Association of Drainage Contractors, the UK trade body for the drainage industry.

Registered Waste Carrier

Registered with the Environment Agency, so your waste is handled and disposed of fully within the law.

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