drainage
Blocked drains and drain clearance
Clearing a blocked drain costs £80 to £200 for a straightforward job, rising to £250 to £450 where jetting or a CCTV survey is needed. Lifting the manhole cover before you call tells you a great deal about which of those you are facing.
What this covers
What it costs. A straightforward drain clearance is £80 to £200. Full cost breakdown.
What the job covers
- Clearing blocked sinks, baths and toilets
- High pressure jetting of external drains
- CCTV drain surveys and reports
- Root ingress and collapsed drain diagnosis
- Soil stack and gully clearance
What is involved
The first diagnostic is free and takes two minutes. Lift the nearest inspection chamber cover. If it is empty and clean, the blockage is between the house and that chamber, which usually means a sink, basin or toilet trap and a job measured in an hour. If it is full, the blockage is downstream of it, in the run towards the sewer, and that is a jetting or rodding job. If several chambers are full, the problem may be at the boundary and could be the water company's responsibility rather than yours.
Internal blockages are mostly fat, wet wipes and hair. Wipes marked flushable are the single commonest cause of a blocked soil stack in a modern house, because they do not break down the way paper does. External blockages add roots, which find the smallest gap in a clay joint and then grow into a mat, and displaced or collapsed sections in older clayware.
Where a drain blocks repeatedly, clearing it again is treating the symptom. A CCTV survey puts a camera down the run and produces a report with the defect located to the metre, which is what an insurer or a repair quote needs. Since 2011 the shared drain beyond your property boundary has generally been the water company's to maintain, and they will attend a blockage on it at no charge, so establishing where the blockage sits is worth doing before paying anybody.
Clearing blocked sinks, baths and toilets, one of the jobs a blocked drains specialist is hired for.
Choosing someone for the job
Ask whether the price is fixed or hourly, and what happens if the drain does not clear. Ask whether a CCTV survey is included or extra. Before booking, check whether the blockage is past your boundary, because your water company clears those free. A firm that recommends excavation without a camera survey has not established what it is digging for.
Common questions
Who is responsible for a blocked drain?
Inside the property boundary it is the owner. Beyond it, shared drains and sewers transferred to the water companies in 2011, so they clear those at no charge. Lifting the chambers tells you which side of the line the problem is on.
Do chemical drain cleaners work?
On a slow sink with a soap and hair build-up, sometimes. On a solid blockage they mostly sit on top of it, and they make the job unpleasant and more expensive for whoever opens the pipe next.