Brisbane’s Famous Trees at Root of Building Inspection Dramas
- Written by Andrew Mackintosh, Veteran Building Inspector
When house-hunting for the perfect Brisbane property, you may find yourself drawn to the homes with magnificent established trees in the yard. There’s no denying the beauty of Brisbane’s famous purple Jacarandas, red Poincianas and stately Moreton Bay Figs – but buyer beware! It’s what you can’t see that could quickly turn your dream home into a nightmare. Beneath these majestic trees is an extensive root system that can bust pipes, destroy a home’s foundations, and even cut off a property’s water supply.
If you’re considering purchasing a property with established trees, engaging an experienced building inspector to assess the property first is wise. A comprehensive inspection will reveal any existing property damage caused by tree roots and assess the potential for future problems.
Not all trees are created equal
Everyone loves the iconic Moreton Bay Fig with its dense and wide-spreading canopy. It’s a real winner in the Brisbane climate. However, its aggressive buttress roots can spread over significant distances, causing damage that is expensive and time-consuming to fix. And it’s not just the Moreton Bay Fig that has a history of causing headaches for homeowners. Trees known to cause the most damage include:
- Moreton Bay Fig (Ficus macrophylla)
- Jacaranda (Jacaranda mimosifolia)
- Australian Willow (Geijera parviflora)
- Camphor Laurel (Cinnamomum camphora)
- Paperbark Tree (Melaleuca spp.)
How close is too close?
A tree's height determines how far it needs to be planted from the home. A general rule of thumb is that the root system of a tree will be roughly 2-3 times greater than the radius of the canopy. To put this in context, a jacaranda has an average branch span of 4.5 – 9 metres, requiring the tree to be planted at least 9 metres from the home. It is recommended that homeowners plant trees known to have invasive roots at least 15 metres from buildings, pools, and drainage.
Can damage from tree roots be prevented?
It’s crucial to regularly monitor the growth of trees and take preventive measures to avoid potential damage. If a tree is large with a well-established root system, it is best to get advice from an arborist. Another popular prevention strategy is installing a root barrier into the ground that prevents tree roots from growing outwards. However, if the structure of the tree is already mature, root pruning may be necessary.
Don’t forget the neighbours
Buying a property with large trees can leave you vulnerable to costly repairs caused by root damage – and not just on your own property! Homeowners are responsible for the whole tree, not just what is above ground. A tree’s root system can extend beyond your property boundaries, so if the roots of your tree damage the neighbour’s property, you may find yourself having to pay for their repairs.
Final thoughts
You don’t have to completely abandon your dream of owning a Brisbane property featuring a Moreton Bay Fig. However, it pays to arrange a pre-purchase property inspection to ensure a beautiful tree is not the root of a whole lot of future problems.
