Root & Weed Barriers

Root barrier membranes and weed membranes

The range divides by direction of growth: root barriers stop roots travelling sideways or downward below ground, while weed membranes stop shoots and rhizomes rising through the surface.

Impermeable root barrier

The impermeable root barrier is the DuPont Plantex RootBarrier, a coated non-woven membrane set upright in a trench as a cut-off between planting and whatever the roots would damage. It is the choice for bamboo and for trees close to foundations, drains, walls and services, where roots must not pass at any point along the line.

Permeable root barrier for paths and green roofs

The air and water permeable Plantex RootProtector is made to lie flat under cycle tracks, paths, roadways, drives and green roofs, where roots would otherwise lift or crack the surface but rainfall still has to drain through. Choose this permeable root barrier for any horizontal installation.

Japanese knotweed barrier

DuPont Plantex Platinium is the range's Japanese knotweed barrier, listed against knotweed, giant hogweed, Himalayan balsam, horsetail, marestail, reed, giant reed, couch grass and bamboo. It is the membrane for containing or covering ground where invasive species have been found on development land, verges and riverbanks, and its wide panels cover large areas with few joins.

Heavy duty weed barrier fabric

The heavy duty weed barrier fabric is rated against the same aggressive species and needs no chemical treatment or physical removal once laid. It is the heavy duty weed membrane for ground under gravel, bark, planting beds, hardstanding edges and compounds, where persistent weeds such as couch grass and horsetail would break through a lighter landscape fabric.

Solar farm weed control membrane

Plantex Solar is a UV resistant membrane laid across solar farms and around other technical installations, where vegetation growing up between the rows would shade the collectors and need regular cutting. The solar farm weed control membrane cuts the number of maintenance visits a site needs.

Root barriers for trees, bamboo and knotweed

Tree roots near foundations, drains and services

For trees, the barrier runs between the trunk and the structure at risk, far enough from the tree to leave it a healthy rooting volume and deep enough to reach below the zone where roots grow in that soil. On a service trench the barrier sits on the planting side of the run, while underground service protection above the pipe or cable covers and marks it for future excavation. Near retained trees, tree protection fencing keeps plant and materials off the root protection area for the length of the works.

Bamboo rhizomes

Running bamboo spreads by rhizomes that travel just below the surface and turn upward at any gap. The barrier goes in as a continuous run or ring with as few joins as possible, and is left standing slightly proud of finished ground so that any rhizome arching over the top can be seen and cut. A walk along the top edge each season finds any that have tried to cross.

Japanese knotweed and other invasive weeds

Knotweed rhizomes extend well beyond the visible stands, so the membrane covers the whole infested zone with a margin around it, and on development sites it is laid as part of a knotweed management plan alongside the excavation and disposal that plan sets out. Horsetail, couch grass and Himalayan balsam are handled the same way at a smaller scale, with the membrane laid flat under a cover layer of soil, gravel or hardstanding.

Green roofs, cycle tracks and drives

On horizontal work the membrane goes down at formation level before the sub-base or growing medium, and is turned up at kerbs, edgings and upstands so roots cannot creep round the edge. On a green roof it keeps roots in the planted layer away from the waterproofing below. Where a drive or overflow car park is built with grass and gravel paviours, the permeable barrier beneath the sub-base keeps tree roots from lifting the cells while water still drains through.