Effect Of Trees On Footings (Simplified)
It’s no secret that Australians are fond of trees: over 16% of our country’s entire land area is covered in forest. While have 123 million hectares of forest is beneficial for the environment and your next camping trip, trees can actually be detrimental to your home.
Despite the many warnings that AS2870-2011 has given to design engineers and builders regarding the adverse effects trees and vegetation can have on footings of the house, we still see that recently built houses in Melbourne are surrounded by garden beds and trees.
The effects of trees built on property in Melbourne’s reactive soil could lead to major movements in the footings of your building.
After inspecting severe damage to a recently built two-story house caused by trees, we consulted a reputable Australian builder* to get a better understanding of why builders would ignore warnings by the AS2870-2011. His only response was: “They make the house look prettier in the eye of potential buyer.”
Unfortunately, aesthetics take precedence over the safety of a home. However, very few home buyers are even aware of the damage that trees can have on footings. They have no idea that, should they choose to build gardens and forests around their dream home, it could become severely damaged in less time than it took to build. And why does this happen? The answer is always the same: reactive soil.
major cause of cracks to houses in melbourne
The foundation soil in Melbourne is of a moist clay-like texture and is therefore highly reactive. Reactive soils shrink when they lose water and swell when they absorb water; this means that the footings of your home will be constantly moving along with the shrinking and swelling. Plants and trees exacerbate this problem because they suck the moisture out of soil, causing it to shrink. When plants and trees are placed near the home, the footings of your home will settle due to the soil’s shrinkage. While minor shifts are normal, due to the reactive soil, plants and trees make the problem worse, which can lead to major footing shifts and result in large cracks throughout your home.
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