[College of ACES] [University of Illinois] [Illinois CES]

Re: Heaving sidewalks from street tree roots

ldunn@ci.sunnyvale.ca.us
Fri, 30 May 1997 15:38:22 -0500

I am the Street Tree and Concrete Maintenance manager for the City of Sunnyvale, CA. I am in the middle of a benchmark study on this subject. I have been working for Sunnyvale since 1989 and have been repairing sidewalks since then. Approximately 85% of damaged sidewalk in Sunnyvale is due to displacements caused by tree roots.

We have been primarily root pruning the offending root(s) and replacing the concrete. But there are cases where a tree root cannot be removed without severe health or stability damage to the adjacent tree. In these cases we have used 10 guage steel plates to restrict root expansion. The root to be protected is excavated all the way around. Then a steet plate is installed above and below the root and then bolted together. The root is now wedged between to steel plates. The new sidewalk is contoured up and over the "plated" root.

Currently I am in the process of a benchmark study to discover the best current practices on the subject of tree roots and displaced sidewalks. I have go a lot of information on tree roots and root development. There is little information out in the world on the actual remedy for this problem. The U.S. Forest Service at the U.C. Davis Western Research and Education Center are working on a survey of the problem and are in the stage of soliciting funding to administer research specifically on this topic.

You can either e-mail me or call me at (408) 730-7505 in Sunnyvale

Leonard Dunn
Urban Landscape Superviser
Public Works Dept.
P.O. Box 3707
Sunnyvale, CA 94088