Sewage Backing Up Into the House: What to Do Tonight

It usually starts small. The shower tray takes longer to empty, the toilet gurgles after the washing machine runs, and then one evening grey, smelly water rises through the lowest outlet in the house and does not go down. That lowest point is where the drain’s overflow finds its way out, and in London terraces it is often a ground-floor shower, a downstairs toilet or a basement gully.

Right now: stop running every tap, toilet, dishwasher and washing machine in the house, tell everyone else at home to do the same, and keep children and pets out of the affected room. Then call or WhatsApp a photo to 07861 933265.

Stop it getting worse

Every litre that goes down a drain upstream of the blockage has only one place to go, and that is out of the lowest opening. Ten minutes without water use often lets the level drop back. If you share a drain with neighbours, knock and ask them to hold off too: in a run of terraced houses the blockage may sit under their garden, and their bath is filling your shower tray.

If dirty water is near sockets or an extension lead on the floor, switch that circuit off at the consumer unit. Do not stand in the water to reach a switch.

Find out where the blockage is

Lift the inspection chamber cover outside, usually a square metal or plastic lid in the front path or back garden. What you see tells you most of what matters:

• Chamber full of water: the blockage is further down, past that chamber, possibly in a shared section or the sewer connection.
• Chamber empty and dry: the blockage is between the house and the chamber, inside your own pipework.
• No chamber at all, or it is under a new patio: say so when you call; we will bring the kit to find the line.

Take a photo of the open chamber from above. It is the single most helpful thing to send before we arrive.

Keep yourself safe around waste water

Wear rubber gloves and old shoes, keep cuts covered, and wash hands thoroughly before eating or touching your face. Open windows. Do not use bleach and a drain unblocker together, or pour chemical unblockers into standing waste water: they cannot reach a blockage several metres away, and they leave a caustic pool for whoever has to put an arm into the chamber next.

What we do when we arrive

The engineer starts at the chamber, not the house. Rods or a jetting hose go in from the open end to break up the blockage, and the line is flushed until it runs clear. Most domestic back-ups are wet wipes, fat from the kitchen, or roots in an older clay joint. If the same drain has blocked before, a camera survey shows whether there is a break or dip that will keep catching debris; see drain jetting for how high-pressure water clears the pipe walls as well as the blockage.

Once it is flowing, we tell you what we found and whose section it was in, so you have it for the insurer, the landlord or the water company.

Cleaning up afterwards

Hard floors can be scrubbed with hot water and detergent, then disinfected. Carpet, underlay and anything porous that sewage has soaked into normally needs throwing away; most home insurance policies cover this, so photograph it first. Where water has got under flooring or into walls, our flood clean-up page explains drying and what to look for in the weeks after.

Signs a back-up is on the way

A gurgling toilet, a slow outside gully, a smell from the shower drain on a warm day, or water standing in the chamber when nobody has used anything for an hour. Any of these is worth a booked visit now rather than an emergency one later, and our guide to smells from drains covers the less obvious causes.