Root Barriers

CuTex is a permeable geocomposite root barrier system consisting of a copper sheet mechanically encapsulated between two high strength geotextiles. CuTex acts by safely releasing Cu2+ ions to inhibit root growth, creating a localised zone of inhibition that causes root tips to undergo a progressive collapse.

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CuTex Root Barrier

The copper acts as a signal layer that all plants avert their growth from. CuTex only releases minute quantities of the copper ion and is a safe, yet effective root growth blocking material.

CuTex can provide direct protection from invasive weeds and plants. Particularly the risk posed by Japanese Knotweed to environments such as utilities’ infrastructures and foundations, across a wide range of industries including construction, highways, rail, and water.

CuTex functions not only as a physical barrier, incorporating strong and durable geotextiles, but also as a chemical barrier. It acts by releasing Cu2+ ions into solution. Confocal laser scanning microscopy and differential contrast interference microscopy was used to analyse the morphology of root tips grown in the presence and absence of CuTex. The results demonstrated that when root tips approach the zone of inhibition, they undergo a progressive collapse. The dividing cells at the very tip of the root (the meristem) die off and the cells above the meristem differentiate.

The localised copper toxicology only affects the root exposed to the zone of inhibition making CuTex a safe and effective material for blocking root growth. Over time CuTex releases Cu2+ ions into the soil creating an effective chemical barrier.

Soil layers binded together by the roots (left) vs sample where CuTex was used: roots were confined in the top layer (right).

Japanese Knotweed CuTex Testing CuTex Use and Installation Product Information

Japanese Knotweed

Although Japanese Knotweed is considered to be the most aggressive of invasive plant species, other plants are also grouped within this category: the legislation views these with the same level of importance.

Japanese knotweed affects both natural and artificial habitats: it is particularly well suited to riparian areas, which allows the dispersal of fragments of the plant downstream where new colonies can also form. It is also found colonising man-made habitats such as roadsides, railways and brownfield land.

The plant is primarily spread through rhizome fragments that even when less than 1g in weight could potentially form a new knotweed colony. As well as movement in water, the plant can be dispersed through garden waste, fly-tipping and machine at construction sites. In established colonies, the rhizome can extend up to 7m, while plants are typically 2-3m in height with mature leaves up to 120mm in length.

The large size of the plant results in a significant visual impact on the environment where it occurs. It also can present considerable damage to the affected area: Japanese knotweeds stout rhizomes can push through asphalt, building foundations, concrete retaining walls and even drains.

It out-competes other species which affects landscaping programs. It affects the aesthetics by accumulation of litter in dense thickets, which encourages vermin. It also increases the maintenance costs of buildings. The large infestation of non-native plants along rivers, hedges and railways can also disturb local ecosystems by blocking migration of native plants and animals, which can add huge costs to development and regeneration schemes because contaminated soil must be treated as controlled waste.

Additionally, knotweed is capable of obscuring railway signals and road signs as well as causing trip hazards in paving. Hence, Japanese Knotweed can cause excessive costs for remediation, prosecution and/or compensation claims, especially from neighbouring sites, physical damage to buildings and hard surfaces and harm to the environment (through the repeated applications of herbicides).

Consequently, legislation exists to prohibit its further spread. For example, in the UK it is an offence to plant or otherwise cause Japanese knotweed to grow in the wild or to spread under the UK Wildlife and Countryside act 1981. Under the UK Environmental Protection Act 1990, Knotweed plant material is also classified as controlled waste.

It is not illegal to have Japanese Knotweed on your land; however, legislation requires that you:

Prevent invasive non-native plants on your land from spreading into the wild and causing a nuisance
Prevent harmful weeds on your land from spreading on to a neighbour’s property

You can be fined up to £5,000 or be sent to prison for up to 2 years if you allow contaminated soil or plant material from any waste you transfer to spread into the wild.

CuTex Testing

The Centre for Plant Sciences at the University of Leeds independently assessed the effectiveness of CuTex as a root barrier against Japanese Knotweed, and other invasive plant species. The research was designed to answer three principal questions:

Does CuTex inhibit root growth?
Does the effectiveness of CuTex increase with time?
Is CuTex safe?

Does CuTex inhibit root growth? YES!

To assess whether CuTex can effectively inhibit root growth the University used a range of approaches with different plant species. Testing in a sterile culture using Arabidopsis Thaliana demonstrated how CuTex creates a ‘zone of inhibition’ whereby roots grow towards this zone, but then ceased at approximately 1.5cm from the composite. Even when seedlings were established at different distances all roots stopped at this zone, and seedlings trying to establish within the zone failed to do so.

The most effective demonstration of CuTex was a setup using an upper layer of vermiculite and a lower compost layer separated by CuTex. The vermiculite contains no nutrients to support the development of the plant, and thus the long-term growth and survival of the plant depends on growing through the CuTex. The experiment was conducted using a number of plant species, including Japanese Knotweed, with the CuTex being assessed against a control fabric.

Does the effectiveness of CuTex increase with time? YES!

CuTex in soil will effectively form a chemical barrier as the Cu2+ ions diffuse into the soil. It was hypothesised that the effectiveness of the CuTex increases with time so this was tested by pre-incubating CuTex in an agar media for a period of 4 weeks following which time seeds were sown. The plates where the CuTex had been allowed to incubate indicated a much stronger and larger zone of inhibition abolishing the growth of the seeds.

Is CuTex safe? YES!

The bio-safety of CuTex was tested by assessing how it affects the overall health and growth of plants. Whilst CuTex prevents plants from growing through the composite and within the zone of inhibition, the effects were shown to be relatively localised.

CuTex was not shown to negatively affect the biomass of surrounding plants.

CuTex Root Barrier Effectiveness Report

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Root Barriers Comparison Report

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CuTex Use and Installation

This innovative root barrier is truly multi-purpose and suitable for many applications, especially where water and nutrient flow is important. Conventional root barrier often creates a ‘wet side’ once it has been installed which attracts plant roots while CuTex alleviates this problem as it is permeable.

CuTex can provide a direct protection from root intrusion to foundations and drains, landfill caps, roads, railways, dams and green roofs.

Examples of Cutex Uses

Burial cell lining for Japanese Knotweed and other invasive plants
Vertical root barrier on land/development boundaries
Tree root barrier and bamboo planters
Protection of vertical & horizontal foundation faces
Protection layer under new concrete foundations
Capping of containment bunds
Lining of service trenches (rail and highways)
Water outfall pipe joints where Japanese Knotweed is present

Cutex & SUD’s

SUDS are drainage systems that are environmentally beneficial, causing minimal or no long-term detrimental damage. They are often regarded as a sequence of management practices, control structures and strategies designed to drain surface water efficiently and sustainably, while minimising pollution and managing the impact on water quality of local water bodies.

The use of root barriers to prevent the spread of Japanese Knotweed has traditionally involved the use of impermeable membranes which prevent the free flow of water within soils, thus contributing towards poor drainage and potential flooding.

An important characteristic of CuTex is that it remains permeable while still preventing the spread of Japanese Knotweed and other invasive species.