Drainage

Any garden where water may pool requires drainage. It’s especially recommended for the edges of your lawn to prevent the area from becoming swampy, the edges of flowerbeds to keep plants from drowning, and, of course, along pathways and paving to prevent slipping and erosion. 

In the UK, driveways over 5m2 which are made of a non-permeable material (such as porcelain or natural stone pavers) must have a drainage system installed to prevent flooding, pooling, and erosion. This is in accordance with the Ministry of Housing, Communities & Local Government’s guidance on permeable surfaces in front gardens.

To install a channel drain for your driveway or patio: 

1. Mark out a space wide enough for your channel drain plus 100mm of concrete on either side. 
2. Dig the marked out trench to the depth of your channel drain, plus 50mm for base and a 2mm gap at the top.
3. Add 50mm of mortar, and compact with a plate compactor.
4. Put the channel drain together as a ‘dry run’ and check the fit of the drain in the trench. If cutting is needed, this should be done on the opposite end of where the outlet will be.
5. Begin installing your channel drain at the lowest point (where it meets the drain) and work upwards, installing end caps as needed. 
6. Add the final part of the channel drain, installing the end cap before laying it in the trench.
7. Connect to the main drain/soakaway using a 110mm pipe. This can be done using your drainage channel’s special moulding or the outlet of the end cap. 
8. Pour water on your channel drain to ensure it is fully connected and works well.
9. Cover all grating with masking tape to ensure the gaps won’t be blocked when pouring concrete. 
10. Pour your concrete to a height of 2mm above the grate.
11. Set for 72 hours.

You can learn more in our Guide to Garden Drainage.