Root Barrier Membranes

One option to confine or prevent Japanese knotweed spreading onto or from a neighbouring property would be to install a specialist root barrier.  The root barrier consists of a membrane which must be installed vertically along the boundary to a depth of not less than two metres.  In order for this method of control to be effective the barrier must surround the stand or neighbouring property. Specialist membranes can also be installed horizontally to prevent knotweed growing up into sub-bases, or as an ‘in-situ capping’ operation, where the top growth and top layer of rhizomes are removed and the remaining rhizomes kept in place but ‘capped off’ with suitable membrane to prevent further growth.

Wreford use a combination of assorted specialist, flexible, UV resistant membranes, ranging from copper-lined permeable products to impermeable membranes with a high puncture resistance.  The choice of membrane (or combination of membranes) is dependant upon the requirements and conditions of each individual site.

It is important to note that root barrier membranes are not an eradication method by themselves and will need to be utilised in conjunction with other treatment methods.  Where root barriers are installed vertically along a boundary to prevent knotweed infringing from an adjacent property, a herbicide ‘mop up’ programme will have to be implemented.

In addition to installation, Wreford can provide root barrier to our clients on a supply-only basis.