Root Barriers : Water-Lines

Root Barriers

Root Barriers

A root barrier system has been developed to allow clients to protect sites from attack by the rhizome system of invasive plants such as Japanese Knotweed.

The RootX barrier consists of a copper foil sheet sandwiched between a layer of woven geotextile and a layer of non-woven geotextile all bonded together by needlepunching to create an environmentally friendly, permeable barrier that releases an inert chemical trace controlling the roots and shoots of all plants.

Research on the integrity and performance of this material has been conducted in Germany with excellent results.

Impermeable alternatives to RootX are either DGW 300 or DGW700 polyethylene geomembranes. These can be used for containment of Knotweed or other invasive plants beneath a site. DGW 300 can be joined with double-sided adhesive tape or welded in-situ. DGW700 can be fabricated into large pieces, minimising site joining, with final sealing as necessary with double-sided adhesive tape. These membranes can be used to construct a containment zone within a site boundary without fear of any infestation into the site or costly removal to a licensed tip.

Protection to drains

A root ball of a tree will tend to develop in areas of soil which are the least compacted and where there is a regular supply of moisture and oxygen. When a trench is excavated for the installation of drains or services, the backfilled soil is so well aerated that root development can occur to the bottom of the excavated trench in and around the drain or service. In addition, it is well known that condensation can form around the outside surface of a drain due to difference in temperatures.

This condensation encourages roots to grow around the drains increasing the risk to intrusion. The solution, depending on site conditions, is to install a barrier vertically on the side of the trench nearest to the trees.

Alternatively, the excavated trench can be lined completely with the root barrier before the drain is installed and sealed with joining tape.

Protection to foundations

In the past, trees that were causing foundation movement to buildings by drying out of the clay soil underneath were either felled, which removed vital trees from the urban environment, or very expensive underpinning took place.

Again the solution is to install a vertical barrier between the trees and the buildings, usually in the form of a narrow trench in an acceptable location.

More information on Root Barriers


Call 0800 5878309