Reader Gloria asks:
“I have a tree root growing under my concrete sidewalk and raising it up. What do you recommend I do for this?”
Unfortunately, this common issue doesn’t have an easy fix. Replacing your sidewalk with adjustable pavers is one workaround. Repairing the concrete likely requires pruning back the problem roots and then patching damaged sections.
Root pruning risks injuring or killing trees if done improperly. Success depends on many factors like species, time of year, and tree age and health. Some trees, like Bradford pears, decline after pruning. An arborist can assess your tree’s likelihood of surviving root pruning and recommend the best solutions.
How Tree Roots Damage Sidewalks
Trees often grow surface roots that spread out from the trunk, expanding over time. As the roots grow wider, they push up against surrounding sidewalks and hardscapes. Sidewalks provide ideal linear space for invading roots.
Signs of root damage include:
- Buckling from upward root pressure
- Cracked, uneven sidewalk sections
- Trip hazards where sections lift up
- Widening gaps between sidewalk joints
- Plumbing leaks or backups in your home
The damage keeps worsening as roots expand and neglected trip hazards become more severe for sidewalks and driveways. Roots can also invade and clog plumbing pipes, and unfortunately, you only find out this is happening once backups or leaks occur.
Options for Repairing Sidewalks Damaged by Roots
For moderate damage, quick repairs include:
- Grinding down raised sidewalk sections to eliminate trip hazards. This won’t stop further root growth.
- Patching cracks by clearing debris and filling with fresh concrete. Larger cracks require replacing whole sections.
- Mudjacking through drilled holes to pump concrete slurry underneath, lifting sunken areas. This can slow damage progression.
- Root pruning removes the upward pressure, providing lasting relief. Root barriers also help reduce future root invasion. We’ll discuss this further below.
- With severe damage, full sidewalk replacement may become necessary. Switching to pavers or flexible asphalt avoids future root problems but costs more initially.
Root Pruning to Stop Further Damage
Root pruning involves cutting off the ends of invading roots to restrict growth in problem areas. When done right, this can eliminate sidewalk damage while saving the tree, but excessive pruning can seriously harm or kill the tree.
As a rule, arborists avoid removing more than 25% of the roots because:
- Cutting many roots triggers rapid new growth, re-aggravating sidewalk conflicts.
- Large, intact root systems keep mature trees upright. Cutting key support roots makes trees prone to falling.
- Roots supply the water, nutrients, and stability that trees need. Removing too much deprives the tree.
Arborists know the proper pruning technique for each tree type and situation. DIY pruning risks destroying vital support roots and destabilizing the tree.
Installing Root Barriers for Long-Term Protection
Root pruning only offers temporary relief before new growth resumes. For lasting results, root barriers can be installed along sidewalk edges to redirect roots down and away.
Common barrier types include:
- Deep-driven metal or vinyl edging
- Fabric barriers in segmented sleeves
- Flexible PVC panels
- Rigid molded plastic barriers
Fabric and flexible barriers are easy to install next to sidewalks and foundations, but rigid panels, while stronger, require professional installation.
Professional Tree and Sidewalk Repair
We recommend consulting arborists and concrete contractors rather than tackling extensive DIY repairs. Professionals have the expertise to:
- Accurately diagnose root and sidewalk damage using tools like ground radar
- Assess whether your tree can tolerate partial root pruning
- Install effective root barrier solutions
- Repair concrete surfaces to restore safety and aesthetics
- Use proper equipment and techniques to minimize harm to the tree
While professional services can be costly, they often solve issues completely. DIY attempts without proper experience may ultimately cost more if complications arise.
So, Is Repairing a Sidewalk Damaged by Roots a DIY or Professional Job?
For moderate damage, DIY grinding, patching, or mudjacking is possible, but extensive repairs involving root pruning and concrete work are best left to certified arborists and concrete contractors.
Root pruning is extremely stressful for trees and requires careful techniques. Professionals balance root removal with preserving tree health. They also have the expertise and tools to thoroughly repair sidewalks compared to DIY repairs.
Considering the nuances involved, we recommend consulting professionals to assess the situation rather than tackling major repairs yourself. While pricier up-front, this often provides safer long-term solutions that protect both your trees and sidewalks.
FAQs About Repairing Sidewalks Damaged by Roots
How much does it cost to repair a sidewalk damaged by roots?
Costs vary based on the size of the affected area and the repairs needed. Simple patching or mudjacking could run $200 to $500. Grinding down moderate uplift might cost $500 to $1,500. Extensive sidewalk replacement with root pruning could cost $5,000 or more.
What is the best root barrier for sidewalks?
Deep-driven vinyl and long, segmented fabric barriers tend to provide the best balance of effectiveness, ease of installation, and cost. Rigid plastic panels are a high-performance option but require professional installation.
Should you cut tree roots growing under a sidewalk?
Only certified arborists should attempt root pruning, as improper cuts can injure or kill the tree. Pruning should be minimized, so root barriers are better for preventing long-term sidewalk damage.
What happens if you cut all the roots on one side of a tree?
Cutting all the roots on one side, also called radial trenching, deprives the tree of stability and nutrients from that direction. This often destabilizes the tree later on, making it prone to falling toward the cut side as it tries to rebalance.
Will trees die if you cut the roots?
It depends on the species and how much of the root system was cut. Oaks, hickories, and conifers often decline and die after one severing. Others, like maples, can regrow roots after a judicious 25% pruning. Consulting an arborist is highly recommended before cutting any tree roots.