Which Drainage Pipe Do I Need?
UK Flow Centre buying guide
Choose drainage pipe by what the pipe must do
The first decision is simple: are you collecting water from the ground, or carrying water from one point to another? These need different pipe.
1. Choose the route by purpose
2. Understand the main options
- Perforated land-drainage pipe: for collecting water from surrounding ground into the pipe.
- Solid underground drainage pipe: for carrying water to an outlet, chamber, ditch or approved connection.
- Soil and waste pipe: for building drainage applications where that system is appropriate.
- Twinwall: for larger, robust underground runs where the installation calls for it.
3. Match the pipe family before choosing the diameter
The links below are exact catalogue examples. Diameter still needs to be chosen from the expected flow, catchment, fall, cover, loading, fittings and the project or drainage design. A larger-looking pipe is not automatically the right pipe.
| Pipe family | Live examples | Selection limit |
|---|---|---|
| Perforated land drain, 50 m coil | 60 mm, 80 mm or 100 mm | Collects groundwater through perforations. Install in a designed trench with suitable aggregate and soil-control layer where required. |
| Solid underground PVC-U carrier pipe, 3 m | 110 mm or 160 mm | Carries water in a non-pressurised gravity system. Confirm compatible sockets, seals, fittings, fall and access points. |
| Unperforated HDPE twinwall | 150 mm / 3 m, 225 mm / 3 m or 300 mm / 3 m. The same product page also has 6 m options. | For larger carrier runs only where the design, couplers, seals, cover and loading requirements suit it. All 3 m and 6 m lengths are collection only. |
Twinwall joints need the matching parts
Plain-ended twinwall pipe needs a compatible socketed fitting or coupler. For a watertight unperforated run, use the sealing arrangement specified for that pipe system. Do not assume a same-numbered diameter from another range will fit.
Cherry Twinwall Double Socket Coupler · Cherry Twinwall Sealing Ring
Manufacturer reference: Cherry Pipes twinwall range.
4. Plan the installation, not just the pipe
- Confirm the source of water and the legal/appropriate discharge point.
- Allow a workable fall for gravity drainage, or design a pumped solution where gravity will not work.
- Choose pipe diameter around the catchment and expected flow.
- Plan chambers, access, rodding points, junctions and transitions before the trench is closed.
Confirm the outlet before buying pipe
The receiving ditch, watercourse, soakaway, sewer or chamber can determine the whole layout. Confirm ownership, permissions, levels, capacity and any required approval before excavation. For building and paved-area drainage in England, check the current Approved Document H guidance; other jurisdictions and project types can differ.
Quick choice
- Wet lawns, fields or landscaped ground: start with a land-drainage layout, then plan how collected water will leave the system.
- Downpipes, surface water or carried water: use solid drainage to take it to the intended outlet.
- Large buried run under loading: consider the strength and installation requirements of twinwall.
Planning a pumped drainage route? First establish the water condition, lift and discharge duty in our pump selection guide.
Technical guidance from UK Flow Centre, operated by JK Irrigation Ltd. Explore all guides in the Technical Hub.
