Pavement Damage from Tree Roots: Causes and Solutions

You have probably seen asphalt pavement or concrete sidewalks with tree roots popping out from underneath. As trees grow, they might cause the asphalt or concrete to heave and break. The jagged edges of these uneven breaks can become tripping hazards and damage car undercarriages and tires. Pavement damage from tree roots is not only an eyesore but can also lead to injuries if not addressed promptly. In this post, we will examine how tree roots can damage asphalt and concrete and offer a few tips on how to prevent this from happening to your pavement.

When roots do not have enough room to grow underground, concrete and asphalt pavement starts to take a beating and become damaged. Trees obtain their nutrients from the earth, and their roots gather oxygen from the non-compacted soil beneath roadways, driveways, parking lots, and sidewalks. When the ground beneath a tree becomes compacted, to give structural support for new pavement, the tree’s roots start quickly gathering beneath the pavement surface. The surface then rises, breaks, and causes safety and aesthetic issues. What’s more, smaller roots can penetrate through existing pavement cracks, which causes further damage by weakening the concrete or asphalt structure.

The best plan of attack is not to plant trees too close to a pavement surface and to be sure that the roots can grow downward by having non-compacted soil below the subgrade of paved areas. But, this is only possible if the property is still being constructed or undergoing renovations. If not, you are stuck with full-grown trees that have already taken root.

If you notice cracks and other signs of deterioration on your pavement surface that is near trees, here are some of our recommendations:

As you may know, asphalt and standing water do not mix well. This is why new pavement is installed on a slight incline to prevent excess water from pooling on top of it. Tree roots have a natural instinct to go wherever the water is. If you’re installing new pavement near trees, make the grade and inclination run in the direction of the trees so that the roots can reach the most water as possible. If you do the opposite, and the inclination goes down the opposite direction as the trees, the roots will travel under the pavement to reach moisture. It is ideal to utilize a drainage system that prevents the tree roots from crossing the pavement.

If you see areas in your parking lot, driveway, sidewalk, or roadway that have been pushed up; there is a good chance that tree roots are already trying to weasel their way through those cracks.

If small roots are already visible, we recommend cutting away the damaged portion of the pavement using an appropriate gas-powered asphalt and concrete saw. After you cut away the damaged sections, carefully trim the fine roots back to the tree. Also, installing a root barrier (see the next solution on this list) will prevent them from growing back. Once the small roots have been trimmed away, clear the area of debris, and then pour asphalt patch into the cut sections. With the use of a handheld metal-headed tamper or a vibrating plate compacter, tamp down the asphalt patch until completely compacted.

For professional contractors, infrared asphalt repair is another great alternative to cutting the asphalt. The infrared machine is positioned over the damaged section and turned on for a few minutes until the asphalt is heated throughout. The heated asphalt is then shoveled into a hot box while removing the small roots. After that, the heated asphalt is poured back into place and compacted using a vibrating plate compactor.
You should consider a tree risk assessment before cutting roots.

Installing a root barrier will prevent roots from growing and becoming a problem in the future. Some types of chemical root barriers available on the market can harm trees and the environment, which is why a physical root barrier is a more sensible option. Physical root barriers are made of solid materials, like sheet metal or fiberglass, and will redirect the roots to grow away from pavement surfaces.

It is ideal to install a root barrier at the time of planting, but obviously, this is not always possible. You can install the barrier as you make repairs to the root-damaged pavement.

Root barriers should be installed vertically and below ground level. If you are trying to protect the entire length of a driveway, parking lot, sidewalk, or roadway; then you can install the barrier in a wall-like fashion. Otherwise, install the barrier around the tree(s) with the open side facing away from the asphalt or concrete surface.

The pavement professionals at Pavement Solutions have over 3 decades of experience building strategies for asphalt and concrete pavement on commercial and residential properties. We are here to assist you for the full lifecycle of your pavement, contact us to prevent asphalt and concrete damage.

Reach out to our experts for a free price quote today: submit a request form or give us a call at (815) 675-0696.