The main difference between Flexible Coiled Land Drain and Rigid Twin Wall Land Drain is strength. The outer ribs on the twin wall rigid pipe add significant mechanical strength to the structure, so rigid land drain is generally used in areas where additional strength is required, such as under a driveway or other areas where traffic may pass over it.
Also if the drain is particularly deep, the large amount of backfill material above it will be heavy so rigid twinwall is a good idea in this situation. Flexible coiled land drain in gardens and fields can be used up to a depth of 1.2m without any danger of the structure being compromised.
Unlike underground ducting, where the colour of the duct signifies what type of service is being run through it, colour is irrelevant when it comes to land drainage. Whilst most land drains are either black or yellow, it is purely down to the manufacturer as to what colour they decide to produce – there are no rules or regulations governing this.
Although coiled land drains are by their very nature flexible so bend are not required, we do sell joiners for connecting two lengths of pipe together. These are a loose-fit push fit joint – no seals are required as unlike foul or surface water drainage there is no requirement for joints to be watertight in a land drain installation.
Multi-purpose Y Junctions are also available for the 80mm and 100mm coils, these are particularly useful when using the traditional “herringbone” layout for installing land drains.