🌳 Why Tree Roots Damage Driveways 🚧

/ by Jon Smith / in Blogs

🌳 Why Tree Roots Damage Driveways 🚧

Tree roots are a major cause of structural damage to paved surfaces. Their relentless growth, driven by the search for water and nutrients, exerts significant pressure that can lift and crack asphalt and concrete.

Key Reasons for Root Damage

  • Water & Nutrients: Roots naturally grow outward and downward, seeking moisture. They will exploit existing cracks, seams, or weak spots in the driveway to access water trapped underneath.

  • Expansion & Pressure: As roots mature, they thicken and expand in diameter. This growth exerts immense and continuous upward force, easily lifting and cracking even heavy-duty concrete or asphalt.

  • Soil Compaction: Heavy vehicle traffic on the driveway compacts the soil surrounding the tree. This compaction starves the roots of necessary air and space, causing them to push up closer to the surface to find space, resulting in damage.

  • Poor Drainage:

    • Waterlogged Soil: Can encourage roots to grow upwards to escape excessively saturated conditions.

    • Dry Soil: Conversely, very dry soil can draw roots toward any source of water, such as leaky irrigation or sewer pipes running underneath the driveway.

Prevention & Solutions

Strategy Description
Plant Wisely Keep large trees at least 20 feet from driveways; smaller trees 10 feet away. Choose deep-rooting or root-friendly species.
Root Barriers Install barriers (e.g., plastic, metal) vertically into the ground to deflect roots away from the pavement.
“No-Dig” Construction Build driveways over the root zone using specialized systems (like soil cells) that allow root growth while supporting vehicle loads, avoiding excavation.
Root-Friendly Paving Use permeable pavers or materials that allow water and air to pass through, reducing the need for roots to seek out cracks.
Protect Existing Trees Use structural soil or cellular systems to build roads/driveways above ground level without severing roots or compacting the soil around mature trees.

What to do if Damage Occurs

  • Assess: Determine if the issue is roots or other factors (e.g., settling, sinkholes).

  • Call Professionals: Consult an arborist and/or a paving contractor for safe and effective solutions such as:

    • Slab jacking (lifting cracked slabs).

    • Root pruning (must be done with caution by a certified arborist).

    • Full replacement of the damaged section.

  • Fix Drains: Repairing leaking drains and pipes prevents water from continuously attracting roots to the pavement area.