A bath has two openings for water to leave by: the plughole at the bottom and the overflow higher up. Together with the pipe that links them, these make up the bath waste and overflow. Knowing how they work helps you choose the right replacement and spot problems early.
The Bath Waste
The bath waste sits in the plughole. Like a basin waste, it lets you hold water in the bath and release it when you are done. It connects to a trap underneath, which holds a water seal to stop drain smells coming back up.
The Overflow
The overflow is the opening near the top of the bath, usually at the tap end. If the bath is filled too high, or a tap is left running, water flows into the overflow instead of spilling over the edge. An overflow pipe carries this water down to the waste, where it joins the main outlet.
How They Work Together
The waste and overflow are usually supplied as a combined set. The overflow pipe runs from the overflow fitting down to a connection on the waste body, so all water leaves through the same trap. This means there is only one route to the drain, and only one trap is needed.
Main Types of Bath Waste
- Click-clack – press the plug to open or close it.
- Pop-up – opened and closed by turning the overflow handle, so you never reach into the water.
- Plug and chain – a traditional plug attached by a chain to the overflow.
- Retainer wastes – the plug is held by the overflow fitting, so it cannot get lost.
- Exposed wastes – visible pipework on freestanding and roll top baths.
- Bath filler wastes – fill the bath through the overflow instead of from a separate spout.
Size
Bath wastes in the UK normally use a 1½" (40mm) connection, which is larger than a basin waste. Check the size of the plughole and the overflow hole in your bath, as some baths need a specific size.
Common Problems
- Slow draining – usually hair and soap building up in the waste or trap.
- A plug that will not stay closed – often a worn click-clack spring or pop-up mechanism.
- Leaks under the bath – can come from worn seals at the waste, the overflow or the trap.
- Smells – may mean the trap seal has dried out or the trap needs cleaning.
Replacing a Bath Waste
On a panelled bath you will need to remove the panel to reach the waste and trap. On a freestanding bath the parts are already visible. Check whether your bath has a separate overflow and make sure the new set suits the bath's holes. If you are not confident with plumbing, use a qualified installer.
Choosing a Finish
The plug and overflow cover sit on show inside the bath, so choose a finish that matches your taps. On freestanding baths, exposed pipework makes the finish even more important.
Shop Bath Wastes
Browse our bath wastes and see our full waste and traps range. Our guide to how traps work explains the water seal in more detail.