USU Forestry Extension Uses New Sidewalk Technology to Save Trees

Trees provide welcome shade for pedestrians, but their roots can wreak havoc on concrete sidewalks. A promising solution from outside the city limits may provide an ideal fix to preserve trees, while keeping urban pathways safe and walkable.

In partnership with Logan City, Utah, Utah State University Forestry Extension is using innovative sidewalk tiles made from recycled farm materials to restore sidewalks damaged by tree roots — without removing the trees.

Mike Kuhns, Forestry Extension specialist, professor and head of USU’s Department of Wildland Resources, first learned of the recycled tiles and saw them in use while on sabbatical several years ago in Seattle. He and Forestry Extension educator Megan Dettenmaier felt the technology could benefit USU’s local community.

“Our aim when we started this project was to save trees,” says Dettenmaier, who earned a master’s degree in wildlife biology from USU in 2012. “We heard about flexible sidewalk tiles used in other areas and decided to give them a try.”

At first glance, the tiles, made from recycled plastic used in agricultural applications, including large polyethylene sheets used to cover corn silage, are hard to distinguish from conventional concrete sidewalk materials.

“Upon closer inspection, you can see specks of plastic and other materials in the tiles,” Kuhns says. “Each tile has half-circle lugs that enable you to connect them together and anchor them securely at an installation site.”

At sites where trees roots have caused sidewalks to shift and buckle, the damaged concrete is removed and replaced with the tiles that fit seamlessly into the existing sidewalk. The plastic tiles expand and contract as a tree continues to grow without damaging the sidewalk or causing a tripping hazard.

“The tiles adapt to any size of sidewalk and can be moved and reused,” Dettenmaier says.

Forestry Extension secured an $8,000 Community Forestry Grant from the Utah Division of Forestry, Fire and State Lands to initiate the project in fall 2014. Logan City matched and exceeded the grant funds, providing $10,000, along with the labor to install the tiles at 12 sites.

Jed Al-Imari, street maintenance manager for Logan City, says tree removal is a significant expense for the northern Utah town. Some 90 percent of sidewalk hazards, he says, are caused by trees and their roots.

“Our first installation of the tiles was in March 2015,” Al-Imari says. “We’ll watch the tiles for a few years, see how they perform and consider expanding the program.”

Saving trees provides a ripple effect of benefits, say Kuhns and Dettenmaier.

“If you can extend the life of the tree, having that mature tree for five more years is useful and valuable,” Kuhns says.

“There’s a whole realm of benefits in keeping trees in place,” Dettenmaier says. “Trees contribute to the health and aesthetics of a community. A tree shades a street, a home and lowers energy costs. We’re learning trees benefit mental health. And there are many benefits to keeping a community a walkable, which encourages people to walk more and use cars less.”

Additional partners in the project include Stokes Nature Center, which added an interpretive sign detailing the benefits of trees, to its Logan Canyon facility, and Superior Sign of Logan, Utah, which donated the sign.

“We’re excited about this unique partnership between varied members of the community,” Dettenmaier says. “We hope it will continue to expand and benefit our community.”

For more information about the Logan Sidewalk Project, visit its website.

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Contact: Megan Dettenmaier, 435-797-8424, megandettenmaier@gmail.com

Contact: Mike Kuhns, 435-797-4056, mike.kuhns@usu.edu

Writer: Mary-Ann Muffoletto, 435-797-3517, maryann.muffoletto@usu.edu