Collapsed Drain Pipe? Signs, Causes and Repair Options

Drain pipes don’t last forever. As they age, they develop cracks and fractures that weaken them, and in the end a section can partly or completely collapse. We see collapsed drains more and more in Stockport, where many homes still rely on their original clay drains.

The good news is that a damaged drain doesn’t always mean a big dig. This guide explains the warning signs, what causes pipes to fail and the two main ways we repair them.

Warning signs of a collapsed or failing drain

A collapse rarely happens without warning. Look out for:

• The same drain blocking again soon after it has been cleared
• Sinks, showers and toilets all draining slowly at once
• Bad smells outside, near a gully or manhole
• Water backing up and overflowing at the lowest gully
• Damp patches, dips or sinking in the lawn, patio or driveway above the pipe
• Rats in the garden or around the house, which can get in through broken pipes

None of these proves the pipe has collapsed. A blocked drain can cause most of them too. That’s why we always look inside before recommending a repair.

Why drain pipes crack and collapse

• Age. Older clay pipes have rigid joints. Over the years they crack, shift and separate.
• Ground movement. Clay soils shrink in dry weather and swell when wet, which puts strain on old pipework.
• Tree roots. Roots find their way into small cracks and open joints, then grow and force them wider.
• Heavy loads. Vehicles, skips and building work above a shallow pipe can crush it.
• Poor earlier repairs. Badly made joints or the wrong materials can fail years later.

How we find out what’s wrong

The first step is a CCTV drain survey. We send a camera through the pipe so we can see whether it is cracked, has a displaced joint or has actually collapsed, and exactly where the problem is. If the drain is blocked, we clear it first so the camera can get through. Where we need to know the route or depth of the pipe, we can trace it from above ground.

We’ll show you the footage and explain what it means. If it’s a one-off blockage and the pipe is sound, we’ll tell you that too.

Repair options: patch or dig?

There are two main ways to repair a damaged drain. You either excavate the ground and replace the broken section, or you repair it from the inside with a patch.

No-dig patch repair

If the pipe is still in shape but has a crack, fracture or open joint in one spot, a no-dig patch repair can often seal it. A resin-soaked patch is pushed into place through an existing manhole, inflated against the pipe wall and left to harden. Your driveway or garden stays as it is. We do patch repairs only.

Excavation and replacement

If a section has fully collapsed, is badly deformed or can’t be reached for a patch, the only proper fix is to dig down and replace it. We use the camera and tracing equipment first so the dig is in the right place and no bigger than it needs to be. Read more about our drain excavations and repairs.

Is a collapsed drain my responsibility?

Not always. Since October 2011, shared drains and lateral drains outside your property boundary have generally been the responsibility of the water company, which is United Utilities across Stockport and Greater Manchester. A drain that serves only your home and sits within your boundary is usually yours. If the damage turns out to be on the public side, we’ll tell you.

What to do if you think your drain has collapsed

• Use as little water as you can until it has been checked
• Don’t force drain rods into it, as this can make the damage worse
• Keep children and pets away from any sunken ground
• Get it looked at with a camera before agreeing to any big repair

Worried about a damaged drain?

We’re a family-run team based in Cheadle, covering Stockport, Cheadle Hulme and the surrounding areas, 24 hours a day. Call 07375 521027 or send us a WhatsApp with a photo and we’ll give you honest advice on what to do next.