In short
Before you ask anyone for help, find the inspection chamber nearest the blockage. Standing water tells you which side it is on. Clear what you can safely reach with drain rods, and stop if you see sewage, more than one fixture backing up or the same blockage returning. If the water still will not move, request a quote online, because pushing a stubborn blockage further along the pipe usually makes the job harder.
Step 1: Find the blocked chamber
Most properties have a line of inspection chambers, or manhole covers, between the house and the boundary. You may see them in the garden, on the driveway or in a paved strip at the side. Work outward from the house and lift each cover in turn. Take care, because covers can be heavier than they look.
Check the water level in each chamber, since it shows where the blockage sits:
- A full chamber with an empty one after it means the blockage sits between the two
- If every chamber is empty and flowing, the blockage may be closer to the house or inside a fixture
- If every chamber is full out to the boundary, the problem may be beyond your property
That last case matters, because you may be rodding a section that is not yours to clear. Where a pipe serves more than one property, the owners may share it, and beyond the boundary it may be a public sewer. Read our guide on who is responsible for a blocked drain if you are not sure.
Step 2: Basic safety before you start
Drain water carries germs, so a few precautions matter. Wear rubber gloves and old clothes. Keep your face away from the open chamber, and keep children and pets well back.
Wash your hands and arms thoroughly afterwards, and do not touch your face while you work. Replace each cover securely when you finish, since a loose or missing cover is a trip hazard.
Step 3: What drain rods will and will not clear
Drain rods are flexible sections that screw together. You can fit a plunger head, a corkscrew or a scraper on the end. Feed the rods in on the upstream side of the blockage, then push and turn gently towards it. Go gently, because force is more likely to jam a head or crack an old clay joint than to clear anything.
Always turn the rods clockwise, because turning them the other way can unscrew the sections and leave a head stuck in the pipe. That turns a simple attempt into a dig.
Rods work well on loose, shallow blockages, such as leaves and silt in a gully. However, they are less good at reaching far along a run or breaking up hard fat and scale. If you push the rods further and further with no result, you have reached their limit. Our comparison of drain jetting versus drain rods explains why jetting can reach and clear more.
Step 4: What a plunger will and will not do
A plunger uses water pressure to move a blockage close to a fixture. It is worth trying on an outside gully that is clogged near the surface with leaves. However, it will not work on a blockage deep in a run, because an open chamber gives it nothing to seal against.
Stop here and ask for help if
Some signs mean you should stop and ask for an engineer, because more rodding will not help:
- More than one fixture in the house is affected, which points to the main run
- You see or smell sewage, rather than rainwater or greywater
- The blockage keeps coming back in the same spot
- The rods hit something solid that will not move
- Water rises again after you think you have cleared it
A repeat blockage often points to a cause such as roots, a cracked pipe or a sagging section. In these cases, a CCTV drain survey shows what is wrong before more time goes into rodding, since rods cannot fix a cracked pipe. Our guide to emergency drain problems covers what to do if sewage is backing up into the house.
What help can cost
UK cost guides put basic drain unblocking at about £80 to £150. MyJobQuote and Book A Builder both give that range. These are guide figures, although your quote may differ. Ask the engineer for a written quote and ask whether there is a call-out charge.
Asking for help
This site is a request service for drainage work. You send your details through the form, and your request goes to an engineer who can respond. Since the engineer who takes your job runs a separate business, the engineer sets the price and the arrival time. Agree both before work starts.
Our external drain unblocking page explains the usual methods for gardens, driveways and shared back greens, while the form lets you request a quote online.
Each town has a page for this kind of job. Inland, see drain unblocking in Forfar or drain unblocking in Perth. In Fife, read about blocked drain help in Tayport and blocked drain help in Wormit.
Frequently Asked Questions
How do I find my outside drain?
Look for manhole covers in the garden, driveway or a paved strip at the side. They usually run in a line from the house towards the boundary. Lift each cover and check the water level, since that shows where a blockage sits.
Can I use bleach or a chemical drain cleaner outside?
It is best to avoid them, because repeated use can wear older pipes without clearing the problem. Chemical cleaners suit minor fixture blockages, not outside chambers.
Will a plunger work on an outside drain?
Only for a shallow gully blockage near the surface, because plungers need a sealed surface to build pressure. An open inspection chamber does not give you one.
How do I know if it is my drain or Scottish Water's?
Citizens Advice Scotland says owners are responsible for household waste pipes up to the point where they join the public sewer. However, if the chamber nearest your boundary is full and the blockage seems to continue beyond it, the fault may be in the public sewer. Our guide on drain responsibility explains the boundary in more detail.
What if rodding does not clear it?
That usually means the blockage needs professional jetting rather than more rodding. This is most likely if you have already tried a fair length of rod without result, since rods have a limited reach.
