PermaTrak Tree Root Crossing Series

WSDOT Dayton Ave - Shoreline, WA Tree Root Crossing

For those boardwalk, trail, and bridge designers looking to protect trees and tree roots, this is a great application of our traditional PermaTrak concrete boardwalk.

We hear it more and more from engineers and landscape architects:

  • "It's critical that our work not harm the trees."
  • "We are trying to work around the critical root zone to comply with this Heritage tree ordinance."
  • "What's the best way to collaborate with an arborist?"

We established the PermaTrak Tree Root Crossings series to specifically address these concerns. Check out some of the key benefits of this series and take a look at our comprehensive guide for designers at the button below.

Read our Tree Root Crossings Guide for Designers


Common Use Cases

  • Observation platforms near significant trees (Heritage trees)
  • Trails and boardwalks navigating through critical root zones
  • Parks and green spaces
  • Extension of pedestrian walkways
  • Elevated sidewalks
  • Upland wetlands


Key Benefits


Tree Root Series:
Increased slip-resistance in wet, shaded conditions
Superior durability and reduced impact from tree canopy
Design flexibility for pier location placement to avoid critical root zones
System allows for air and water circulation around roots
Easy installation with minimal site disturbance
Reduces need for grading and excavation
ADA accessibility and inclusive design
On ground footing option to comply with Heritage tree ordinances
Top down construction capabilities
Modular system allows for "flex" and natural movement
In-house engineering team with over a decade of tree root crossings experience


Tree Root Crossing Case Study: North Dining Hall at Wake Forest

Here's a video explaining how we partnered with Stimmel Associates to design a tree-root crossing series boardwalk at North Dining Hall on the Wake Forest Campus.

This content was originally part of a collaborative presentation between PermaTrak President Jason Philbin, P.E., M ASCE and Stimmel Associates Partner Kimberly Barb, PLA, LEED AP BD C at the Carolina Thread Trail Forum.


  • 00:00 - Introduction
  • 00:50 - Wake Forest University Project Details & Challenges
    • 01:17 - Challenge #1: ADA Compliance
    • 01:54 - Challenge #2: Minimize Tree Impact
    • 03:27 - Challenge #3: Student Safety
    • 04:03 - Challenge #4: Minimize Maintenance Needs
  • 04:30 - Solution
  • 05:14 - Critical Root Zones
  • 05:51 - Foundation Considerations for Tree Root Crossings
  • 08:57 - PermaTrak Precast Concrete Piers
  • 10:05 - The Finished Project


Installation Video

"It's like adult LEGOs" is what we hear from contractors. Here's a video of our tree root crossing series being installed at Julian B Lane in Tampa, FL.


Photo Gallery