Internal drains are the waste pipes inside a building. They link sinks, baths, showers, toilets and appliances to the main drain outside, while a block can sit in one fixture's pipe or in a shared pipe or stack. Finding the right spot saves time.
Count the fixtures that run slowly. One slow fixture points to its own trap or pipe, while several slow fixtures point to a shared pipe, and the block may even sit outside the building. Tell the engineer what you counted.
This page covers the inside of the property. For gullies and manholes, see external drain unblocking. Single fixtures have their own guides, such as the one for a blocked sink, since each blocks in its own way.
Indoor waste pipes are narrow, so small amounts of waste build up fast. Grease, soap and hair coat the walls, while wipes and paper catch on rough joints. Over time, the coating narrows the pipe until water backs up.
Long flat runs may block more often, because water moves slowly there. Older pipes can also have rough walls that hold debris. Even so, many indoor blocks respond to ordinary tools.
A job often starts with a few questions. Which fixtures are slow, and since when? The answers show whether the block sits in one trap or a shared stack.
Waste pipes have traps, clean-out plugs and access caps. Opening them lets tools reach the block. Floorboards rarely need lifting, although a hidden pipe may need access.
Rods, augers or a small machine move the block. A water jet may follow to clean the pipe walls, although the method depends on the pipe size and material. Ask why the engineer chose it.
Running each fixture shows whether the flow is free. If one still gurgles, the fault may lie further down. That is a sign to ask for a camera check.
The engineer who takes your job runs a separate business, so the engineer sets the price, the arrival time and any guarantee. Use these questions to compare quotes, since answers differ from one engineer to the next. Write the answers down, because a written note helps if the job changes.
MyJobQuote lists drain cleaning at £80 to £100 and rodding at £80 to £145. Book A Builder gives £80 to £150 for basic unblocking. These are UK guide ranges, not Dundee quotes, so real prices may still differ.
A block in a hard-to-reach stack can cost more, so ask whether the price covers all the fixtures you named. Then ask for the quote in writing before work starts, since the scope changes the price. Compare two quotes for a large job.
When more than one fixture is slow, the block is probably in a shared waste pipe or the underground drain. Single traps are less likely to be the cause, although it is worth checking them. Say which fixtures are affected when you send your request.
It can. A block may make water leak from a joint or overflow from a trap, while slow leaks can leave damp patches on walls and floors. For that reason, deal with a persistent block early. Mention any damp in your request.
Usually not, since most waste pipes have traps and access points that tools can use. If a pipe sits out of reach, ask the engineer to explain the options before work starts. Agree any extra cost in writing.