Waste Traps

How Waste Traps Work

Waste traps utilise a water seal; by always holding a small amount of water, gases are not able to pass through the trap and enter the room, and wastewater is still able to flow into the underground drainage system. The depth of the water seal in waste traps is recommended to be 75mm when installed on most household appliances, and 50mm for a few others such as baths and showers to be in accordance with Section 1: Sanitary Pipework of the UK building regulations.

When it comes to trap diameter, 32mm is recommended for a washbasin or bidet and 40mm is recommended for everything else, including baths, showers, sinks and washing machines.

Following these guidelines will ensure that the trap seal is effective, even on high use appliances, whilst also preventing siphonage from occurring. FloPlast's waste traps feature a universal compression end which allows them to fit to both push fit and solvent weld waste pipes.

Watch our video on how to replace a leaking trap for more information about different trap styles and how they work.

Different Types of Waste Traps & Applications

• P Trap: One of the most commonly used types of traps that feature a 75mm water seal and are most often used as basin and sink traps.

• S Trap: Similarly to P traps, these are also very common and mainly used on sinks, and use their shape to hold their water seal.

• Bottle Trap: Whilst bottle traps are also used on sinks and basins, they are often used in applications where the plumbing is exposed, as opposed to being hidden behind a wall or within the basin itself. They are used this way due to their more compact and neat appearance.

• Telescopic Bottle Trap: A variant of the bottle trap that features a telescopic neck that can be slid up and down in order to accommodate a range of distances between the waste pipe and drain.

• Anti-Syphon Bottle Trap: The anti-syphon variant is used in applications where there is a higher chance of siphonage occurring than usual, such as the connected waste pipe having a steeper fall than usual.

• Telescopic Pedestal Trap: These compact traps are designed to be able to fit inside or behind a basin pedestal, allowing them to be concealed.

• Bath Trap: We offer both standard and low-level bath traps, which have a 50mm water seal and are designed to be used on baths.

• Washing Machine Trap: For connecting washing machines and dishwashers safely to the waste system, two washing machine traps are available. Standpipe traps are used when the washing machine has a waste pipe connection separate from a sink and the standard version can be used when the washing machine needs to connect to the kitchen sink's waste pipe.

• Shower trap: Another type of waste trap that has a 50mm water seal, shower traps feature a removable chrome finish grid, allowing for easy maintenance.