We all know that to inhibit the growth and spread of roots you can place a barrier in their way. There are many different root barriers on the market and while many do the job quite well they come with limitations, for example not being permeable. The problem with non-permeable root barriers is that if used vertically they can create concentration of water in the soil on one side, a ‘wet side’, which actually attracts roots to grow in that area. You then have to rely on the physical strength of the barrier alone to stop the roots pushing through. The slightest weakness or hole will be exploited by determined roots. If non-permeable root barriers are used horizontally they can end up creating a puddle on top of them, leading to waterlogging of the ground above.
So how can a root barrier be manufactured that is both permeable and prevents roots from growing through it? Well there is a product on the market now called CuTex Root Barrier. It was previously called Root Barrier X which has been renamed to highlight the fact that a fine micro-perforated copper layer is used within it. This copper layer is bonded between two layers of polypropylene geotextile, one woven and one fleece, creating a sturdy and flexible fabric. This root barrier has a strong track record having been used for over a decade in specialist site applications, including containing Japanese knotweed and redirecting tree roots.
The manufacturers, GeoFabrics, wanted to test CuTex in a lab environment to see if the micro-perforated copper layer did more than allow water through and act as a physical barrier to roots. They enlisted the research skills of The Centre for Plant Sciences at the University of Leeds, who were asked to independently assess the effectiveness of CuTex as a root barrier to Japanese knotweed and other invasive plant species. Their results supported the anecdotal evidence that the copper layer inhibits root growth. They used a range of techniques and growing situations to monitor the difference between using CuTex and a control.
Confocal laser-scanning microscope images of the resulting samples were able to demonstrate the smooth development of root tips in the control, contrasted with the deformed development of root tips in close proximity to CuTex. The results showed that when root tips approach the zone of inhibition they undergo a progressive collapse. The dividing cells at the very tip of the root die off and cells above the meristem differentiate.
These findings are very exciting for a number of reasons. Firstly this revolutionary root barrier can be used for long term containment of roots and rhizomes. CuTex has an excellent track record already when used for mitigation against the rhizomes of Japanese knotweed in dig-out situations. It has been used both on property boundaries to prevent incursion from neighbouring land, and used to create cell burial of contaminated soil within the site. (Thus avoiding the costly operation of taking Japanese knotweed contaminated soil to licenced landfill sites.) Over a ten year period of being used in the field we are unaware that infestations of Japanese knotweed have reoccurred where CuTex has been installed by PBA.
Secondly, due to its versatile nature, CuTex Root Barrier can be installed around underground services to prevent root infiltration which would cause expensive repairs. It can be cut, manipulated and affixed to awkward shapes, as can be seen in the photo below. It can be retrofitted in situations where foundations have been excavated and need protection, or installed in new-build development sites and civil engineering situations. With an estimated efficacy of over 100 years, installed properly, CuTex Root Barrier will provide an effective solution that can be relied upon.
Case Study:– Tree Roots Causing Subsidence
CuTex Root Barrier has been successfully used as part of remediation packages for subsidence where trees are in close proximity to buildings. There are now several companies using CuTex as a component in containing tree roots as an alternative to property underpinning. The advantages of this revolutionary root barrier lie in the root inhibiting properties of the copper layer, combined with the permeability of the root barrier which means that soil on both sides of the barrier can naturally normalise moisture levels. This can offer substantial cost saving for insurance companies called to pay for subsidence claims.
Case Study:– Civil Engineering Project, Wales
Recently we were contacted regarding the development of a link road and existing junction improvements as part of the Mountain Ash Cross Valley Link near Cardiff. This major traffic project in the Cynon Valley will see a bridge built over the river and railway in Mountain Ash, linking communities with the main A4059 road by the end of 2019. With Japanese knotweed proving to be a major problem in Wales, this site required a method of capping a large area of ground with a permeable root barrier that would stifle any Japanese knotweed growth. CuTex was specified as the right product for this job and was installed with a topping of fresh uncontaminated soil as part of the new landscaping.
Case Study:– Brownfield Site – Banstead
A developer was looking to remove three existing dwellings on an extensive plot and build a single replacement building providing an 80 bedroom care home for the frail and elderly. They discovered a significant infestation of Japanese knotweed. A major dig-out was required, with the resultant contaminated soil transferred to a landfill site registered to accept contaminated waste. CuTex Root Barrier was then installed around the perimeter to prevent any Japanese knotweed still existing in neighbouring properties from creeping back in.
Case Study:– Housing Estate Tree Root Containment – Essex
Uttlesford District Council adopted the infrastructure, landscape and highways to a large housing development. Lime trees had been planted to create an avenue to frame a public foot path that runs through the site. A number of home owners saw that the limes were undermining the block paving of their shared driveway and wanted the Council to take action to resolve this problem.
The home owners were also concerned about the potential damage that trees could cause to their driveways and homes. PBA initially completed a visual survey to investigate the driveway damage to ascertain if this can be attributed to tree roots. The survey confirmed that roots were in contact with the block paving and were thought to be exploiting the damp sandy conditions found in the construction layer of the drive.
A plan of action was recommended to prevent root proliferation within the block paving sand layer which, given time, could cause lasting damage to the drive. PBA supplied and supervised the installation of CuTex permeable copper root barrier. This was deemed as the best solution in this situation given the unique properties that CuTex offered over other root barrier solutions.
You can find further details regarding CuTex specifications and a Data Sheet PDF for downloading at
The Research Summary is now Published
Simply email firstname.lastname@example.org and say if you would prefer an electronic copy or a copy in the post along with a sample of CuTex for you to touch and feel.
Alternatively you can call PBA on 01202 816134 for all your CuTex Root Barrier enquiries.