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If you are planning a new DIY plumbing project in your home, or carrying out some important reparations on a waste or drainage system that is not working as well as it should, chances are that you will need purchase or replace plastic waste pipes and connectors.

These essential pieces of kit are necessary to keep clean water and waste running smoothly through your property and will make for efficient and reliable systems in your home. There are several important things to know about plastic waste pipes and connectors, however, before you get started.

Firstly, there are several different sizes of plastic pipe that are suited to different types of project. The smallest size, the 21.5mm pipe, is suitable for overflows such as cold water tanks and cisterns. The next size up, the 32mm waste pipe, is used for hand basin waste water.

The 40mm pipe is ideal for a sink and bath waste pipe, whilst the 110mm soil pipe is needed for main drains. Each of these different types can be found at your local building supplies stockist, where you will also be able to get further advice on which one is best for your needs if you have any doubts or questions about right type of pipe to purchase.

All the different sizes and types of plastic waste pipe available – from the 21.5mm overflow pipe to the 110mm soil pipe – are manufactured from a variety of materials. These include: ABS, a tough material used for hot and cold waste water; uPVC, again a resistant material good for both hot and cold waste water; and PP, a tough but flexible material that is suitable for hot and cold waste water.

Which kind of material you choose for your 21.5mm overflow or 110mm soil pipe all depends on the method of joining you intend to use and whether or not you want to use the plastic pipe outdoors. PP differs from the two others; it cannot be used outdoors and is not suitable for joining with solvent. It is, however, the least expensive option.

When installing your plastic pipes you will have the choice of three different methods of joining or connecting them. The first is solvent, where certain types of plastics can be bonded together using solvent cement. Although this method and these plastics are easy to use, the disadvantage is that you only have one chance to make the connection due to the strength of the sealant.

A less ‘permanent’ and more flexible way of joining your 110mm soil pipe or 40mm bath waste pipes together is by using an ‘O’ ring. For this method, the pipe is simply pushed into the connector of corresponding diameter where the ‘O’ ring forms an effective seal. Pipes can be taken out, cut and readjusted if necessary, unlike with the solvent joining method.

The ‘O’ ring connector method is often used with the 110mm soil pipe to join two different types of plastic pipe. These are comprised of the external down pipe and another pipe that is installed below ground.

The final type of connector used is the compression waste pipe connector. Here, the compression screw and seal are first removed from the connector before being slid onto the pipe. After this, the pipe is inserted into the connector and the seal pushed back into the mouth of the connector, where it is then fixed. This method can be easily readjusted, much like the ‘O’ ring connector.

These are the basics of the different plastic waste pipe types and the most common joining methods used. Your choice, of course, all depends on the demands of your particular project, your level of skill and the different types of materials that your budget can afford.

The Different Types of Plastic Waste Pipes and Connectors