Tree Risk Assessment Workshops with Ed Hayes, Safe Trees, LLC

My workshops include classroom presentations and a hands-on outside field exercise. Continuing education credits are available from the ISA and other organizations depending on the state or country. These credits generally range from 6-7 per day. There are options for one or two day workshops that always include at least a half-day field exercise. Additional time may be needed to include tree dissections as this would involve additional resources. A workshop can be tailored to fit your needs.

Available workshops;

1. Basic to advanced Tree Risk Assessment with an afternoon field exercise (1 day).

2. Basic to advanced Tree Risk Assessment with a ½ day tree dissection workshop (1½ days).

Agenda 2014 and beyond;

"Tree Risk Assessment"; a Safe Trees, LLC, workshop, offered by: Ed Hayes, Owner/Operator of Hayes Tree, LLC and Safe Trees, LLC and author of the "Evaluating Tree Defects", Field Guide.

"A comprehensive, systematic and practical approach to evaluating potential tree hazards".

Morning agenda: 8:30am until noon.

Introduction, including the new ISA risk assessment matrix.

Tree decay, modes of failure, and species profiles.

Tree mechanics, vector forces, attributes if wind loading and responsive growth.

Break; mid-morning around 9:45am.

Evaluating decay above and below ground.

Tree Defects, assessing the "Likelihood of Failure".

Mitigation options and examples in practice.

Lunch; noon until about 12:45pm.

Afternoon field exercise 1:00 pm - 3:30 to 4:00 pm; defect evaluations (stress risers), responsive growth, tree mechanics, decay evaluation, equipment and technique.


Pre-work in highly recommended and will be supplied by Safe Trees, LLC, in advance of the seminar, and one or more resources available from the ISA are essential references for practicing Arborists. These include the ISA BMP, "Tree Risk Assessment", and the 2013 ISA, manual; Dunster, Julian A., E. Thomas Smiley, Nelda Matheny, and Sharon Lilly. 2013." Tree Risk Assessment Manual". Champaign, Illinois: International Society of Arboriculture.

Additional course materials used in seminar; some available for down load now.

Pre-work document for seminar; "Risk Assessment Math"

Using the ISA BMP Risk Rating Matrix, (down load pdf).

Common tree defects for selected temperate climate deciduous broadleaf and conifer species.

Species material strength.

ISA Tree Risk Assessment Field From, ((down load pdf).

ISA Likelihood of Failure, by defect or condition, (a 2-page front/back for field use).

ISA Risk Rating Matrix: (a 2-page front/back for field use).

Legal considerations for tree risk assessment.

Limitations of cross-sectional strength; strength loss formulas and guidelines.

Suggested references and those used in seminar.

For interest contact Ed Hayes; Email ( or (

Workshop reports

2011 Workshop Report

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