Vertical root barriers
Vertical root barriers are typically used at boundaries to prevent encroachment to or from adjoining land. They are installed to a depth of 2-3 metres depending upon the depth of the knotweed rhizome.
A trench is dug with a mechanical excavator. The root barrier membrane is positioned in the vertical plane as close to the boundary as possible. Finally the trench is backfilled with appropriate fill material, with particular care being taken to avoid damage to the membrane.
Horizontal root barriers
Horizontal root barriers can be used to protect specific surfaces such as roadways, drives, etc. where it has not been possible to remove all Japanese knotweed rhizome. The root barrier simply forms a barrier, which actually encourages more lateral spread. A sacrificial zone is usually provided at the edge of the root barrier, such that if new growth does appear it can be treated with herbicide.
Root barriers are usually employed in conjunction with removal methods to minimise the risk of regrowth in critical areas. For advice, please call us today on 01932 868 700.