+61 2 9418 7750 d.hall@buildreport.com.au



Cracks and deflections occur to buildings for many reasons. One common reason is tree roots. Cracks can also occur due to brick growth, structural settlement, structural roof movement, expansive soil movement and structural deflections.

A tree may have been planted with the best of intentions, but they grow in size and most people do not consider the damage a mature tree can do to a building. Also the size of the root system can vary between different trees and will have an impact.

During prolonged dry periods where there has been little or no rain, the tree will naturally seek out water so that it can survive. That is only one reason why cracks may appear in a building. As can be seen in the photograph, tree roots can lift up a building.


Also most trees have a fine root system which extracts moisture from the soil. That is particularly relevant to expansive soils which vary due to moisture content. The fine root system can result in uneven settlement of a building and results in ongoing cracks to both internal and external walls. As the tree root cracks are ongoing, they can be classified as structural as the cracks will increase in size over time unless the correct remedial works are undertaken.



The actual identification of the reasons and causes of cracks can only be determined by a building expert who will take into consideration the type of building, type of soils, size and type of tree and its location. There are sometimes solutions that can be offered where the tree remains and the buildings are protected from tree root damage.

Cracks can also occur for a number of reasons and without adequate expert advice, the wrong diagnosis of the cause can result in works being carried out that may have no benefit. An expert must also provide unbiased information and not recommend a product or contractor unless it will provide a desired result.