Root barriers can prove a key asset in landscaping and construction projects. Used in a targeted way, long-term cost-saving benefits can be gained by eliminating maintenance repairs caused by root damage. However, they can also play a role in preventing legal disputes by stopping root encroachment onto neighbouring land. Installing a bamboo barrier at home, for plant containment, is a project many are now prepared to tackle.

Protection & benefits

At the heart of their functionality is protection, but root barrier membrane offers other benefits. They can facilitate the retention of valuable trees, curbing the need for removal and its associated costs. Used in this way, they contribute to environmental conservation efforts.

Root barrier is also an essential tool in tackling some of the most tenacious invasive plant species. Halting knotweed and bamboo at property boundaries and preventing infiltration from next door. Ecological benefits and cost savings can be achieved by using Japanese knotweed root barrier membrane to create on-site burial cells – reducing or diverting impacted waste away from landfill. 

They provide landscapers the flexibility to design with a variety of species. Plant distribution can be optimised and controlled by guiding root growth. After the initial outlay, the lasting advantages of root barriers make them a great choice for sustainable and cost-effective landscaping.

Bamboo barrier installed against a fence

Root barrier applications

Commercially available root barriers are usually designed with a specific purpose in mind. There are products capable of resisting the growth of tree roots, shrubs, and invasive species. However, they can also play a crucial role in preventing root-related issues, such as: root spiralling, undermining structures, and compromising utility services. 

Trees

The different tree root barrier types for the task at hand: 

When planting new trees, a root barrier director can be employed to guide roots away from hard surfaces, foundations, and utility trenches. 

Protection from trees involves installing liner barrier around the area to be protected, which is sometimes away from the trees.

Trees planted in an urban area can benefit from ribbed root barrier – installed around the trees – to draw roots down and helps prevent root spiralling.

In cases where existing trees pose a threat a deep-rooted barrier system is often utilized to effectively block roots, a critical measure to preserve the integrity of structures and infrastructure. 

Choosing the right root barrier for you

The process of choosing the best root barrier for a project involves careful consideration of the product features. A clear distinction exists between these two options: 

Weed membranes, known for their permeability, are most effective when covered with mulch or gravel to inhibit the growth of annual weeds. Their primary function is to create a barrier that prevents weed growth. This minimises the need for constant maintenance and reduces competition for nutrients. 

Root barriers, in contrast, commonly employed in vertical installations, offer resistance against the roots of trees, shrubs, and invasive plants. Some root barrier variations are versatile: serving both vertical and horizontal applications.

The decision of which solution to employ depends on the specific requirements of each project. 

Specialist root barrier types & materials

Different geotextile materials are available, each serving distinct purposes. These include:

• Composite root barriers featuring a copper layer.
• Vertical ribbed root barriers.
• Permeable non-woven polypropylene geotextile for weed suppression.
• Semi-rigid, non-permeable HDPE barriers for vertical applications.
• Flexible, impermeable laminated woven geotextile for root barriers.

Selecting the appropriate barrier or membrane is crucial to achieving a successful project outcome.

Root barrier secured to fence

Installing root barrier

A carefully executed barrier installation is vital. Following manufacturer guidelines and seeking professional assistance when required are critical steps in the process. Whether you’re redirecting tree roots or containing bamboo rhizomes, tailoring the root barrier depth and coverage to the specific scenario is essential. 

A critical process when designing a root barrier solution, is consideration of how to join or bond the barrier.  Joining two barriers together requires specialist barrier joining tape, best combined with a fold technique called the ‘prayer fold’. This is where two upstands of geotextiles are folded into one another. 

The bonding root barrier to other structures requires root barrier adhesive to ensure a good seal is achieved.  For larger projects, heat welding root barrier can be a more effective solution. 

Plan ahead before starting, ensuring that correct tools for making a root barrier have been selected and protective measures are taken during the installation process.

Completed root barrier installation

Know your limits – when to enlist help from professionals

Ensuring safety and a good standard of work is a priority, if uncertain, select a professional root barrier installation company. Not doing so, and trying tackle a project beyond your skillset, could impact your track record or reputation.

The requisite skills for various common scenarios include: 

• Heat welding expertise 
• Construction competencies for large-scale horizontal root barriers
• Micro digger or soil saw proficiency for bamboo root barriers
• Deep digging and knotweed expertise for tasks like Japanese knotweed burial cells 

Root barriers are an indispensable tool in the professional landscaping toolkit. They offer not only protection against invasive roots but also ecological advantages and substantial cost savings. When employed correctly, they become a sustainable and efficient solution that provides enduring benefits for your landscaping projects.

By Jon Barton, MD of root membrane specialists, Root Barrier Store.