Blocked rainwater drains: causes and fixes
Most people do not think twice about their rainwater drains until they overflow.
It starts with a puddle. Then the gully bubbles. Before long, your driveway or patio floods every time it rains.
At ASL Limited, these jobs come in all year round. The surprising part is it often starts with something small.
What usually causes it?
The usual culprits include leaves and moss from the roof, roof silt washed down from old tiles, bits of plastic, wrappers, or cigarette ends, gravel or block paving sand, DIY downpipes pushed too deep into gullies, or disconnected joints underground. Sometimes, it is something more serious, such as a collapsed section of pipe or a system where rainwater and foul waste are wrongly combined.
How we fix it and why timing matters
When ASL Limited gets a call, the team does not just clear the gully and go. The drain is jetted, camera surveyed, and traced to see where it goes, because what looks like a simple blockage could be hiding a bigger issue.
If cracks or damage are found, the same question is always asked: is it early enough to line it? Can the rough edges be ground down to put a smooth liner in?
Drain lining is a brilliant solution. It is a no-dig repair where a new internal pipe is installed without having to dig. Lining only works if you catch old pipes early. Most people leave it too late. Surface water drains are the worst for this. By the time ASL Limited is called in, they are often too misshapen, sunken, or collapsed to be lined. In those cases, excavation is needed. If your drain is already overflowing, or even just gurgling, it is better to check it now, not later.
Real job: blocked gully outside the conservatory
One customer thought it was just leaves. The drain was jetted, a camera was run, and the pipe was found to be collapsed directly under the patio slab. It was not obvious until heavy rain hit, but the damage had been building for months. The section was dug out and replaced before installing a sturdier gully pot with a filter. The problem was solved, but it was too far gone for lining.
Warning signs to watch for
- Gully bubbling when it rains
- Gurgling downpipes
- Pooling water after rain
- Moss or damp along the wall base
- Overflow near patios or garages
Why call ASL Limited?
ASL Limited has been sorting drainage problems like this for over 25 years. The blockage will not just be cleared. The cause will be shown, options explained, and it will be fixed properly. No guesswork. No shortcuts. Just a lasting solution.
Need help with a blocked rainwater drain?
Call ASL Limited on 0800 181 684. The drain will be cleared and the cause found before it gets worse.
We cover Surrey, Berkshire, Hampshire, West Sussex and South West London.
