A drain that keeps blocking after being cleared often has a problem further along the pipe that the first clearance did not reach. It may also be down to the way the pipe was laid, damage to the pipe, or what is going down the drain each day. Finding the reason is the key to stopping it coming back.
The Blockage Was Only Partly Cleared
Sometimes a plunger or drain rod pushes a hole through a blockage rather than removing it. Water starts to flow again, so the job looks done. But the rest of the waste is still clinging to the pipe, and new debris soon catches on it.
This is common with grease and hair, which can form long, sticky layers inside a pipe. If only the first part is cleared, the drain may slow down again within weeks.
Build-Up Along the Length of the Pipe
Even when one blockage is removed, the pipe walls may be coated with fat, soap or limescale. This narrows the pipe along its length. Water still drains, but more slowly, and anything solid is more likely to get stuck.
In kitchens, this often happens where a sink waste runs a long way before reaching the main drain. In bathrooms, it is often linked to hair and soap in shower and bath wastes.
Problems With the Pipe Itself
A drain pipe needs a steady slope, called the fall, so that water and waste keep moving. If the fall is too shallow, or the pipe dips in the middle, waste can settle in the low spot. A pipe that has sagged or been knocked out of line can behave in the same way.
Underground pipes can also crack, shift at the joints or let in tree roots. These faults can catch waste again and again. They cannot be confirmed just from a drain blocking more than once, so further investigation may be needed to find out what is going on.
Habits and Shared Drains
Daily habits play a big part. Pouring fat down the sink, flushing wipes or letting hair go down the plughole will keep feeding the problem. Small changes, such as binning fats and using plughole covers, can help a clear drain stay clear.
If neighbours have similar problems, the blockage may be in a shared pipe. Thames Water explains that sewers shared with neighbours are usually its responsibility, while pipes serving only your property within its boundary are yours. Knowing which applies can save time.
For blockages inside your property, our page on clearing blocked sinks, baths and outside drains explains the work we can help with.
When you call a plumber about a repeat blockage, tell them how often it happens and what clears it each time. This history can point towards the cause more quickly.
If your drain keeps blocking, call Emergency Plumber Swindon on 01793 569521. We can help homes and businesses in Swindon look into the problem and find a longer-lasting fix.