A Quick Guide to Installing Underground Drainage

Installing and replacing underground drainage pipe systems can be a big job to take on without the help of a professional, but it is, nevertheless, entirely doable. The key to making good work of the job is by taking the time beforehand to learn about the different types of underground drainage pipe available, safety requirements, installation techniques and applicable laws and regulations.

First of all, it is important to note that if you are installing new runs of underground drainage pipe or changing existing ones, you are legally obliged to inform your local Building Control Department and provide them with drawings of your proposed project. If you are simply replacing damaged pipes, however, this is not necessary.

Your choices of underground drainage pipe are vast and varied, although all are brown in colour. Clay and Plastic uPVC are the most common materials now used for underground drainage pipe products, with uPVC being the most affordable and therefore more popular, although clay is still more appropriate for regions with significant soil movement.

If you are using the most common option, plastic uPVC pipes, you will be able to find lengths of both 3m and 6m very easily from all good plastic building supplies stockists. The advantage of these long lengths is that fewer connectors are required when installing the runs of underground drainage pipe.

The uPVC pipes can be easily cut to size using a standard, fine-toothed saw. After cutting, be sure to make sure the end is chamfered and cleaned of any dirt. Joining pipes will depend on whether your pipes are straight connection or socket format. For the former, a collar connector is used to connect sections of underground drainage pipe.

Before laying your underground drainage pipes you will need to dig a trench for them. All pipes should be laid in a trench that is 300mm wider than the pipes themselves. In addition to this, all plastic pipe runs need to be laid on a 10mm layer of pea shingle or fine gravel. This will provide a base for larger grade material and backfill to be placed on top later.

Be sure to follow safety requirements when digging your trenches, including: making sure the site is fenced off from children and pets, never working in trenches alone, keeping trench widths as small as possible to stop the sides from collapsing, not working in bad weather and not having the trenches open for too long to avoid collapse.

In addition to this, if your trench is more than 4 foot deep, legal requirements state that it must be shored up. Once you have installed your underground drainage pipe system, it is important to check for leaks. After this has been done, you can finally backfill your trenches.

You will need to place 100mm worth of granular material over the underground drainage pipe systems you have installed before filling in the rest of the trench with selected backfill material. In the chosen backfill material, no stones over 40mm in size should be present, nor any frozen material or clumps of clay over 100mm in size.

If there is any danger that your newly-laid underground drainage pipe system can be damaged by contact – for example through the use of garden tools – it should be covered by a layer of protective paving stones.

There is, of course, a lot more involved in planning, installing and testing underground drainage systems than what is mentioned here, although this is this basic process that you will need to follow when undertaking the job.

For expert guidance, consult a trustworthy local tradesman for assistance or check in with a reputable local or national plastic building supplies stockist to make sure that you are purchasing all the correct materials that the project requires. In addition to this, make sure you are adhering to all local and national regulations before getting started.