While the sporadic tree branch or storm-fallen tree can be easily identified as a potential issue for homes in wooded areas, tree roots are often (quite literally) overlooked. However, root systems have a far greater reach than their above-ground counterparts, and these unseen, interconnected networks can drastically affect foundational walls, pathways, driveways and sewer lines.
When it comes to trees with roots that can cause costly damage, there are particular species that homeowners should be aware of. While most root systems benefit soil stability, some trees develop aggressive root systems that can wreak havoc on human-made structures. Some of the species to keep a wary eye on include:
Unsurprisingly the most common group of trees in Australia, the Department of Agriculture, Fisheries and Forestry estimates that Eucalypts cover 101 million hectares, which is 77% of Australia’s total native forest area! While symbolic of Australia’s natural beauty, the 800 species of the Eucalypt family are renowned for their aggressive root systems. Eucalyptus trees can cause significant damage to your home’s foundation, driveway, walkways, and even sewage lines if not given the appropriate space to grow.
Oaks are a true European staple populous in the Adelaide Hills. While renowned for their stalwart strength and dazzling autumnal colours, their shallow root systems can spell trouble for pavements and sidewalks.
The hardy Ficus genus of trees is ubiquitous in the streets and parks of Australian cities. While remarkable for their ability to withstand changing conditions, figs have an extensive root system that can be a menace to property foundations, sidewalks, and plumbing.
Signs of tree root damage to your property
Just like any living creature, trees require water and nutrition. Their roots seek out these life’s essentials and can, in their journeys, impact the stability of your walls, foundations and even plumbing systems. It is important to recognise signs of tree root damage, such as large hard and lumpy patches in the lawn, raised or sunken pathways and driveways, or trees growing in a manner that is uneven or tilted. Checking foundations for tree damage can be more difficult, as the culprit is often not visible and may require the assistance of a professional. A professional building inspector should be able to identify any structural damage to the building caused by tree roots. As unattended root damage can create significant and costly issues when neglected, it’s important to take action quickly.
It's in the soil!
Tree roots’ impact on your property isn’t just contingent on the tree itself. Soil type has a profound impact on the damage caused by tree roots. Areas with looser, poorly compacted soil are more likely to suffer from heaving sidewalks or driveways. Heavy clay soils can be a barrier as roots struggle to break through the compact material. It’s essential to identify how your property’s soil structure will react to tree roots before deciding whether or not to plant trees near existing structures on your property.
Preventing and mitigating tree root damage
Australian Standard AS 2870-2011 recognises the importance of the placement of trees close to a home’s foundations, the removal of trees prior to or after construction, and the growth of trees that may be too close to the home’s footing.
Before finding a new patch of soil to plant a tree, it’s essential to check for ground excavations, high-pressure utility lines or sewage systems in the vicinity. You may also wish to consider using a root barrier between 1-2 feet from the foundations of buildings if the soil is shallow. A root barrier is a dense sheet of plastic that stops roots penetrating into specific areas. After planting or relocating, water your tree regularly until it becomes established – a healthy tree will naturally be better at rejecting invasive roots over time. With foresight and care, you can enjoy picturesque fruit-bearing or ornamental trees around your property with only limited upkeep.
Repairing damage vs removing a tree
Deciding whether to repair the damage caused by a tree or to remove it is ultimately up to the homeowner. While repairing the damage can be more cost-effective in the short term, it’s perhaps more pertinent to consider the long-term costs associated with this approach. Over time, if repairs are made repeatedly, expenses could mount significantly, in which case simply removing the tree may have been the wiser option.
Rehoming Your Tree
What about council trees?
Most often, homeowners only have to worry about the trees on their own land. However, in some cases, council trees in adjacent yards, or near the road, may become a pressing issue. The best course of action is to get in touch with your local council as soon as possible. If a council tree poses a legitimate threat to surrounding homes, your council may consider finding a new home for the tree, pruning back its branches, or simply removing the tree in its entirety. Before the council may take action, they will likely wish for the tree to be evaluated by a qualified arborist, to ensure the best possible outcome for all parties involved. Always remember that cutting down a council tree is illegal, and that simply contacting your council is the best way to avoid accidental legal troubles.
The Bottom Line
It’s impossible to deny the appeal of a densely wooded suburb. Cooler summer days, painterly autumns, and sweet-smelling springs are just a few of the benefits. However, it’s important to periodically lift our rose-coloured glasses and be critically aware of the damage that tree roots can cause Adelaide’s property and how to manage them effectively. With a thorough understanding of how to spot root damage, homeowners can take proactive measures to ensure that their homes are well protected. If you suspect your property may have been damaged by tree roots, we strongly encourage you to pick up the phone or flip open your laptop to seek professional advice. A building inspector will be able to expertly evaluate the damage and give you an accurate insight into what may have caused the issues. At Select Building Inspections in Adelaide, we’re always here to help South Australian homeowners unveil the truth about their homes. With over 20 years of experience in the construction industry, we can provide comprehensive inspections and reports to give you peace of mind. Don’t hesitate to get in touch today.