Tree Roots Near Foundations and Driveways: What to Do

Can tree roots damage a foundation?

They can, but usually not the way people think. A root doesn't punch through a solid foundation wall. Roots grow where there's water, air, and room. They follow cracks and gaps that are already there.

Where roots can cause trouble near a house:

• They pull water out of the soil, and clay soil shrinks when it dries out. Shrinking soil under one side of a foundation can let it settle.
• They grow into cracks and gaps that are already there and make them worse over time.
• They find old, cracked sewer and drain lines and grow into them.
• A big root growing right against a footing can push on it as it gets thicker.

A lot of yards in Middle Tennessee have clay soil, so the soil drying and wetting matters here. If you see cracks in the foundation or doors that stick, call a foundation pro to look at it. Roots may or may not be part of it.

Do tree roots crack driveways and sidewalks?

Yes. This one is real and common. Concrete driveways, sidewalks, and patios are thin compared to a foundation. Roots grow under them where the soil stays moist, and as the roots get thicker, they lift and crack the slab. Pavers and edging get pushed up too.

This is a big one in Rutherford County, where many yards have thin soil over limestone. Roots can't go deep, so they spread out flat right under the surface, which is right where your driveway is.

Which trees cause the most root trouble?

Trees with big, shallow roots planted close to concrete cause the most trouble. In our area, that's often:

• Maples, which have shallow roots that lift lawns and edging
• Hackberries, with big roots spreading out from a wide base
• Oaks, with thick roots near the trunk
• Big cedars on rocky ground with roots near the top

Can you just grind out the roots?

Often, yes. If the tree is already cut down, grinding out the roots near the driveway or house is simple. The roots are dead and won't keep growing.

If the tree is still alive, it's a bigger decision. Roots hold the tree up and feed it. Cutting a big root close to the trunk can stress the tree or make it less stable in wind. Small roots farther from the trunk are usually fine to cut. For big roots near the trunk, have an arborist look at the tree before anything gets cut.

We can grind on each side of a slab, but not under it. That stops the root from getting bigger in that spot. See root grinding.

When does the whole tree or stump need to go?

Sometimes the answer is that the tree is too close to the house or drive. A tree planted a few feet from the foundation years ago is going to keep causing trouble as it grows. If the tree is already down, grinding the stump and the roots near the house solves it for good.

If a stump is sitting right against the house, behind a fence, or in a tight side yard, see backyard and narrow gate stump grinding. We work close to foundations with care and stop short of anything we can't safely cut near.

What about roots in sewer lines?

Roots are drawn to the water in sewer and drain lines. They get into old, cracked pipes and grow until the line backs up. That's a plumber's job, not a stump grinder's. But if the tree is gone and the stump is near the line, grinding the stump and roots out can help keep it from happening again.

Before we grind near a house, we get the utility lines marked through Tennessee 811. Private sewer and drain lines on your side of the meter usually aren't marked, so tell us where they run.

What can you do to keep roots away from concrete?

• Plant new trees well away from the house, drive, and walks
• Pick trees that don't have big, shallow roots for spots close to concrete
• Grind out roots from dead trees and stumps near the slab
• Ask an arborist about root barriers for living trees you want to keep
• Fix drainage so water doesn't sit along the slab or foundation