What does ISA tree risk assessment actually measure?

ISA tree risk assessment evaluates three components: the likelihood that a tree or part of a tree will fail, the likelihood that failure will strike a target, and the consequences if it does. A tree with significant decay over an empty lawn may be low risk despite poor structural condition. The same tree over a frequently occupied patio is high risk. Risk is about the combination of probability and consequence — not just how bad the tree looks.

When should I call a certified arborist instead of using this tool?

Call a certified arborist when: the tree shows sudden change (new lean, fresh cracks, bark lifting), the tree is within falling distance of a structure or occupied area, you cannot safely see the base of the trunk or the root zone, or the tree is very large (over 40 feet) and near anything you care about. This tool helps triage urgency — it does not replace an on-site assessment.

How much does a tree risk assessment cost in Upstate SC?

A single-tree written risk assessment from Martin Tree and Turf Care runs $150–$300. Our ISA Certified Arborist performs the assessment on-site and provides a written recommendation on whether the tree should be monitored, cabled, trimmed, or removed. Assessment fees are credited toward any work performed. A written report for permit or insurance purposes adds $100–$150.

Can a high-risk tree always be saved?

Not always. Some structural conditions — advanced internal decay, co-dominant stems with included bark at the trunk, significant root system failure — cannot be corrected by trimming or cabling. In those cases, removal is the safer and more cost-effective path. A legitimate arborist will tell you honestly which category a tree falls into rather than defaulting to the most expensive option.

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Tree Risk Self-Assessment

Answer two questions and check off any defects you observe. This tool scores your tree's risk level based on the same framework ISA-certified arborists use — and tells you what to do next.

ISA Certified Arborist

#SO-356834A

International Society of Arboriculture — Cert #SO-356834A

TCI Certified

Tree Climbers International

Tree Climbers International Certified Tree Technician

Licensed & Insured in SC

$1M Liability · $2M Umbrella

Certificate of insurance provided before any job begins

Free Written Estimates

Exact price in writing before any work begins — no surprises on your bill

2-Hour Emergency Response

Emergency line answered 24/7 — any time of day or night

What Makes a Tree High Risk?

Structural Defects

Large cavities, vertical cracks, included bark in a tight V-crotch, and root plate lifting are the highest-risk defects. They reduce the structural load capacity of the tree — sometimes to the point of imminent failure.

Canopy Dieback

Dead wood in the upper canopy is a delayed hazard. A limb that died last year may hold for another season — or drop during the next thunderstorm. Dieback affecting more than 30% of the canopy warrants professional evaluation.

Root Damage

Tree roots extend 2–3 times the canopy radius. Construction, compaction, trenching, or soil grade changes within that zone can kill feeder roots and destabilize the tree years after the event.

Fungal Presence

Visible shelf fungi (conks) on trunk or roots indicate internal decay that may be decades ahead of exterior symptoms. The presence of fruiting bodies means the decay column has been established for a long time.

Target Zone

A high-risk tree in the woods is very different from the same tree over a parking spot or playground. Target zone — what's in the fall zone — multiplies risk. Low-likelihood failure over a high-use area is still a high-risk situation.

Storm History

Trees that survived past storms without visible damage can still have internal fractures or root damage that isn't immediately obvious. Post-storm assessments catch these deferred failures before they become emergencies.

Tree Risk Assessment →Homeowner Risk Guide →Emergency Triage Tool →

Frequently Asked Questions

: ISA tree risk assessment evaluates three components: the likelihood that a tree or part of a tree will fail, the likelihood that failure will strike a target, and the consequences if it does. A tree with significant decay over an empty lawn may be low risk despite poor structural condition. The same tree over a frequently occupied patio is high risk. Risk is about the combination of probability and consequence — not just how bad the tree looks.
: Call a certified arborist when: the tree shows sudden change (new lean, fresh cracks, bark lifting), the tree is within falling distance of a structure or occupied area, you cannot safely see the base of the trunk or the root zone, or the tree is very large (over 40 feet) and near anything you care about. This tool helps triage urgency — it does not replace an on-site assessment.
: A single-tree written risk assessment from Martin Tree and Turf Care runs $150–$300. Our ISA Certified Arborist performs the assessment on-site and provides a written recommendation on whether the tree should be monitored, cabled, trimmed, or removed. Assessment fees are credited toward any work performed. A written report for permit or insurance purposes adds $100–$150.
: Not always. Some structural conditions — advanced internal decay, co-dominant stems with included bark at the trunk, significant root system failure — cannot be corrected by trimming or cabling. In those cases, removal is the safer and more cost-effective path. A legitimate arborist will tell you honestly which category a tree falls into rather than defaulting to the most expensive option.

Know Your Exact Price Before Any Work Begins

The certified arborist evaluates your tree in person and puts the price in writing. That's the number you pay — no verbal quotes that change on arrival, no invoice surprises. No pressure. No obligation.

Get Free Estimate

Or call directly: (864) 913-3978