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October 06, 2022

How and Why Roots Can Damage Concrete

If you have mature trees in your yard, chances are that you’ve got issues in your foundation, driveway, or sidewalk. These often take the form of visible cracks, buckling, or lifting in the concrete slabs.

It’s the tree roots that are wreaking havoc on the paving. But why exactly does this happen? There’s more to it than meets the eye. Let’s review how and why roots damage concrete, and what you can do if you suspect your yard’s trees are damaging your home’s foundation.

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Tree Roots Cause Soil Shrinkage

The entire purpose of tree roots is to soak up water for hydration. They will spread out to maximize their exposure to groundwater. Here in Austin, the dry climate puts extra pressure on tree roots to expand in search of moisture.

Once the ground becomes saturated with water, the roots will soak up as much as they can. This absorption will quickly drain the water volume out of the soil in range, causing shrinkage. As the soil shrinks, it retracts, removing support from the underside of nearby concrete. The slab can easily buckle and crack without a stable foundation of soil beneath it.

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Roots Exert Force on Concrete

Growing roots need space to expand. When they don’t have it, they can push against whatever’s in their way – even concrete. (Don’t underestimate the strength of a tree!)

This will start small with young, thin roots. But as the roots swell up with age, they can muscle their way right through even the thickest concrete. Because concrete is a porous material, it is particularly susceptible to breaking under the forces of growing roots.

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The Canopy Rule of Thumb

If you’re unsure whether or not a tree’s roots actually reach the concrete on your property, take a look up at the tree’s canopy (the top where the leaves are). The branches spread out at the same breadth the roots do. So if your branches naturally reach any paved area, the roots will too.

You’ll want to keep this in mind when you plant any new trees. Make sure you look up the diameter of the tree’s natural canopy at maturity and don’t plant within range of concrete or other structures. This will prevent a lot of stress down the road thanks to avoided damage and repairs.

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Fixing a Root-Cracked Foundation

Your foundation may be affected by root growth if you notice significant cracking or buckling. In some cases, you may be able to see the roots of a nearby tree growing directly into your home’s slab or destroying your driveway or walkways.

When this happens, you’ll need to call in for expert help. In Austin, Texas, Douglas Foundation Repairs has been a trusted choice for decades among homeowners who want thorough, well-executed repairs offered at affordable prices.

We perform full evaluations to give you insight into the extent of your problems, and provide our honest recommendation for the best solution. Our pros always aim to prescribe a fix that gives you the greatest balance of value and effectiveness. Contact us today to set up your appointment.