Ask a Consulting Arborist Q&A: Tree Risk Assessment

Q: Are there guidelines for how close an oak tree should be planted to a house so to not damage it?

Thursday, December 31, 2015  

Q: We live in an 8-year-old townhouse community in Palm Beach County, Florida. The developer planted oak trees in front of the houses. One tree is 4 feet from the pavers to our front door and 8 feet to the water connection to the house. The roots are already starting to cause damage to the pipes and walkways. My question is whether there are some guidelines as to how close to a house an oak tree should be planted? We feel that it was irresponsible for the developer to plant these trees without any thought to long-term growth. Is there a rule of thumb as to how far from a house an oak tree should be planted? Thanks.

A:The planting of large growing canopy trees in locations where the root area is restricted by other improvements is common. We work with many properties where this occurs, especially homeowner and condominium associations. There are guidelines about having enough space for the canopy and root growth of trees by professionals preparing landscape plans and for ongoing maintenance. Damage claims regarding the costs of repair for improvements broken or damaged by the growth of trees have been made by property owners and associations in many locations around the United States.

There is a CRZ--Critical Root Zone--that is based on the minimum root growth area for a particular tree based on the size of the trunk. It is basically 8" of root area width for every 1" of trunk diameter (diameter at breast height). This is part of the American National Standards Institute A-300 Standards for Maintenance of Trees and Woody Plants. Further, planting trees far enough away from structures and improvements to allow for normal mature growth is written into some municipal development codes, so that is another source of the requirements and guidelines that should have been followed.

Feel free to follow up with me about this situation.

 

 

Responder: John Harris, RCA #468, Hollywood, FL