Costs
The Real Cost of Ignoring a Slow Drain: From Free Fix to Four Figures in Six Months
A slow drain gets expensive fast. See the honest cost at every stage — from a £5 plunger to a £4,000 excavation — and why the boring early call wins.
Published 5 July 2026
The Real Cost of Ignoring a Slow Drain: From Free Fix to Four Figures in Six Months
A slow drain is the most boring problem in the world. Water disappears, just… slowly. You can still wash up. You can still shower. It is barely a problem at all.
And then, six months later, you are standing in raw sewage and someone is digging up your garden.
This is the escalation timeline. Every stage is real. Every cost range is honest. The moral is obvious but apparently worth spelling out, because we see this arc play out across the TW postcodes more often than we should.
Stage One: The Slow Drain (Month 1)
What it looks like: Water pools for thirty seconds before clearing. A faint gurgle from the plughole.
What it actually is: The early stages of a partial blockage. Usually a build-up of grease, soap scum, hair or food debris narrowing the pipe. The water still gets through, just not quickly.
What it costs to fix now: Nothing, or very close to nothing. A good plunger costs £5. A drain unblocker product costs £3. Fifteen minutes of your Saturday morning.
If that does not shift it, a professional drain jetting visit (high-pressure water forced through the pipe to blast the blockage clear) runs roughly £80 to £150 for a standard domestic drain in the Ashford and wider TW area.
The temptation: Ignore it. It is barely a problem.
Stage Two: The Gurgle Gets Opinions (Month 2-3)
What it looks like: The slow drain has not improved. Other fixtures are joining in. The kitchen sink gurgles when you flush the toilet. There is a smell.
What it actually is: The partial blockage has grown. It is now affecting more of the drainage run, and gases are being pushed back up through the system. This is your drain telling you it has a problem and would quite like some attention.
What it costs to fix now: A drain jetting visit at this stage still typically lands in the £80 to £200 range, possibly with a CCTV drain survey (a small camera pushed through the pipe to see exactly what is going on inside) added on at £150 to £250. Total: £200 to £450, depending on what the camera finds.
Still a Tuesday afternoon job. Still a tidy bill.
Stage Three: Standing Water (Month 4)
What it looks like: The sink no longer drains at all. The shower tray fills up while you are in it. Outdoor drains are backing up.
What it actually is: Full or near-full blockage. The pipe is not coping. If you are on an older property in areas like Ashford, Feltham or Staines, this is also the point where a partial collapse or root ingress (tree roots that have grown into and through the pipe wall) starts to become a realistic explanation.
What it costs to fix now: Jetting may still clear it, but if the CCTV survey reveals structural damage, you are looking at drain relining (a resin sleeve inserted and cured inside the existing pipe, so you get a new inner surface without digging) at roughly £500 to £1,500 depending on the length and diameter of the affected run.
That is a meaningful bill. It is not yet a catastrophic one.
Stage Four: Sewage Backup (Month 5-6)
What it looks like: Raw sewage is coming back up through the lowest drain in the house. It may be the toilet, a ground-floor shower, or an outside gully.
What it actually is: A complete blockage or structural failure. The system has nowhere to send the water, so the water finds somewhere itself.
Important health note: Raw sewage contains bacteria including E. coli and other pathogens. Do not attempt to clear this yourself without proper PPE. Keep children and pets away from affected areas. Ventilate the space. This is a genuine health hazard and needs professional attention immediately.
What it costs to fix now: If the pipe has collapsed or root ingress has destroyed a section, excavation (digging down to the pipe, replacing the damaged section, reinstating the ground) typically runs £1,500 to £4,500 or more depending on depth, access and how much of the run needs replacing. Garden reinstatement, if required, is on top of that.
You may also be looking at insurance claims, loss assessor involvement, and several days without full use of your drainage.
The Boring Maths
| Stage | Approximate cost to fix |
|---|---|
| Slow drain, month one | £0 to £150 |
| Gurgling, month two to three | £200 to £450 |
| Standing water, month four | £500 to £1,500 |
| Sewage backup, month five to six | £1,500 to £4,500+ |
The slow drain you ignored in January is the excavation you are funding in June. The numbers are not invented for dramatic effect. They are what the work genuinely costs.
What to Do Right Now
If your drain is slow and you are reading this in the early stages: try the plunger. If it does not clear within a couple of attempts, call someone. The call is cheap. The delay is not.
If you are already at standing water or sewage backup, do not wait any longer.
Drainiacs covers Ashford and the full TW postcode area, 24 hours a day, seven days a week. We aim to be with you within the hour for emergency calls. If your drain is giving you any of the warning signs above, call us now on 07700 137648.