With summer approaching, we want to make sure our landscapes are properly prepared for the increase in temperature. Extra heat can dry out the ground, but it also promotes growth.
Often, the root systems of our plants or trees actively search for water, especially during summer. Without proper management and control, those roots can cause damage or spread to unwanted areas.
Root barriers are a proven method for controlling root growth and protecting your property from expensive root damage. Here is what you need to know about how they work and why they are worth the investment.
A root barrier is, as the name describes, a barrier that prevents roots from spreading or growing in a particular direction. Typically made from high-density polyethylene (HDPE), they are placed underground around the plant with enough distance for the plant to grow.
This forms a barrier to stop roots from spreading horizontally. The barrier redirects root growth downwards rather than outwards, protecting nearby structures and infrastructure.
Damage caused by invasive roots can cost homes or businesses hundreds or thousands of dollars in repair costs, especially when water pipes are involved. Tree roots naturally grow towards moisture sources, which is why they frequently infiltrate underground pipes and drainage systems.
For a detailed walkthrough, read our guide on how to install a root barrier step by step.
Root barriers are an effective solution to controlling invasive or spread out root growth, without damaging or hindering trees. It simply places a barrier between the roots and your property.
They work by forcing the roots to grow in either the other direction or downwards. This protects foundations, driveways, retaining walls, and underground utilities from costly root damage.
For standard residential root barrier applications, the 450mm wide barrier roll provides adequate depth to redirect most tree root systems without taking up excessive trench space. For larger trees or commercial projects where deeper root systems are expected, the 600mm wide root barrier roll offers extended protection against aggressive root growth.
Root barriers are made from material that doesn't harm the soil or plants. There are no chemical sprays involved and the process itself does no harm or damage to the environment.
Unlike chemical root control methods that can leach into groundwater or harm beneficial soil organisms, physical barriers offer a completely passive solution. They maintain soil health and don't interfere with the natural ecosystem around your plants.
Our root barrier is UV stabilised and highly dense, so it doesn't need to be replaced frequently. Having to replace root barriers often can result in soil damage.
Quality root barriers are designed to last decades underground without degrading. This makes them a one-time investment that provides continuous protection throughout the life of your landscape.
Other root control methods can be effective, but they don't help with moisture control, which in turn can kill your tree or plant. Our root barriers are designed to retain moisture.
So, although the roots are controlled, they are also fed. This ensures your trees and plants remain healthy while being contained.
Most root barriers on the market are manufactured from high-density polyethylene (HDPE). HDPE combines flexibility during installation with rigidity once backfilled, making it the go-to material for both residential and commercial jobs.
When choosing a root barrier, look for these properties:
Some barriers also feature a ribbed profile that redirects roots downwards rather than allowing them to circle along the barrier face. This is particularly useful for regulating root growth around established trees where the root system is already well developed.
Root barriers serve multiple purposes across residential and commercial landscapes. Understanding where and when to use them helps you make the most of this protective technology.
Selecting the appropriate barrier depth depends on the species of tree and the proximity to structures. Shallow-rooted trees may only require 450mm depth, while deep-rooted species need 600mm or more.
Consider the mature size of your tree when planning barrier installation. A sapling today might develop extensive root systems in ten years.
Consult with an arborist if you're uncertain about root depth for specific species. They can provide guidance on installation distance from the trunk and barrier specifications. The University of Florida's research on root barriers and sidewalk protection provides useful reference data on placement distances for common tree species.
While root barriers are primarily used to protect structures, they also help manage soil erosion on sloped or disturbed ground. Uncontrolled root spread can destabilise soil by creating channels that concentrate water flow, accelerating erosion during heavy rain.
On construction sites and embankments, root barriers are often used alongside erosion control products like coir matting and silt fences to create a layered protection system.
An Australian study on tree root intrusion in urban infrastructure found that unmanaged root systems are a leading cause of stormwater and sewer pipe damage. This backs up the case for managing roots before they cause problems, particularly on sites near existing drainage infrastructure.
If you are dealing with an existing erosion problem where invasive roots are part of the issue, understanding the problems with invasive root growth is a good starting point before deciding on a barrier solution.
While root barriers offer specific protection against invasive root systems, they work well alongside other landscape management and erosion control products. Understanding how different materials complement each other helps create comprehensive site protection.
For surface-level weed suppression around trees and garden beds, the 1.83m wide woven poly weed mat provides excellent ground coverage without interfering with root barrier installations below. When you need natural erosion control on embankments where roots might also be a concern, biodegradable jute matting works well as a temporary surface layer while your root barriers provide permanent subsurface protection.
Proper installation is critical to barrier effectiveness. The trench should be dug to the full depth of the barrier material with the top edge sitting just above soil level.
Overlap joins by at least 300mm when connecting multiple sections. This prevents roots from finding gaps between barrier sections.
Always install barriers at least 600mm from the trunk for established trees. Closer installation may damage existing root structures and stress the tree.
Backfill the trench carefully, compacting soil in layers to eliminate air pockets. This ensures the barrier sits firmly in position and won't shift over time.
If you already have tree roots causing damage and need to act before installing barriers, our guide on managing invasive roots with long-term techniques covers methods you can use alongside barrier installation.
Yes. When properly installed at the correct depth and distance from the tree, root barriers physically redirect root growth downwards and away from structures. HDPE barriers are the most effective option because they resist root penetration and last for decades without degrading.
The key is choosing the right depth for the tree species and ensuring joins are overlapped by at least 300mm so roots cannot find gaps.
The cost depends on the depth and length of barrier you need. A 50-metre roll of 450mm root barrier starts at around $258, while 600mm rolls are around $349. Professional installation adds labour and excavation costs on top of the material price.
For most residential projects, root barriers are significantly cheaper than repairing foundation cracks, replacing lifted pavers, or fixing damaged pipes after the fact.
Root barriers and underpinning solve different problems. A root barrier prevents roots from reaching your foundations in the first place, while underpinning repairs foundation damage that has already occurred. If tree roots have not yet caused structural damage, a root barrier is the more cost-effective and less invasive option.
If damage has already happened, you may need underpinning first and then a root barrier to stop it recurring.
Yes, but you need to be careful not to cut through major structural roots during trenching. Install the barrier at least 600mm from the trunk to give the tree enough root space to stay healthy. For established trees with extensive root systems, consult an arborist before digging.
Learning how root barriers work around mature trees helps you plan the installation to minimise stress on the tree.
Investing in proper root management now saves significant repair costs down the track. Whether you need to protect a residential foundation or manage root spread across a commercial site, root barriers are a proven, long-term solution.
All Stake Supply has been a family-owned supplier of environmental terrain solutions since 1976, with over 1,000 products in stock at our St Marys NSW warehouse. For help choosing the right root barrier for your project, get in touch with our team or call 1300 130 123.
