--- title: Tree Risk Assessment: What an Arborist Checks url: https://battleborntreeservice.com/guides/tree-risk-assessment-what-arborists-check/ business: Battle Born Tree Service address: 6301 US Highway 50 East, Carson City, NV 89701 phone: 775.232.8243 hours: Office Monday-Friday 8:30 am-5:00 pm; phones answered seven days a week; 24-hour emergency service credentials: ISA Certified Arborist WE-11728A on staff; Nevada Business License # 20131580674; fully insured type: Tree service (removal, crane work, pruning, stump grinding, defensible space, snow removal, firewood) --- - [Home](https://battleborntreeservice.com/) - [The Field Guide](https://battleborntreeservice.com/guides/) - Tree risk assessment: what an arborist checks # Tree risk assessment: what an arborist checks A tree risk assessment is an arborist's structured look at a tree's defects, the site around it and what could be hit if part of it fails. It ends in a decision to leave it, prune it, support it or remove it. No tree is ever completely safe, so the goal is to find the ones whose risk is too high. Key takeaways - The International Society of Arboriculture says there is no such thing as a completely safe tree, and that only a small share of trees that can fall ever hit anything. - An assessment weighs three things together: the defect, the chance of failure and what stands under the tree. - Dead branches, cracks, cavities, mushrooms at the base and recent soil or construction changes are the signs worth reporting. - Possible outcomes are routine care, pruning, cabling or bracing, or removal. Cabling is support, never a guarantee. Homeowners usually ask "is it going to fall?" The honest answer needs a trained set of eyes on the tree itself. This guide walks through what those eyes look for, so you know what you are paying attention to when an arborist walks your yard. ## What does an arborist look at on the tree? The ISA's tree owner checklist is a good picture of the starting point. It asks about large dead branches, detached or hanging branches, branches that have already fallen, loose bark, cracks or splits in the trunk or at branch unions, cavities or rotten wood, mushrooms at the base, unusual yellowing or small leaves, and whether the tree has been topped or heavily pruned. An arborist walks around the whole tree rather than glancing at one side. The brochure also names specific defects to look for: poor taper, codominant stems, cracks and splits, external signs of decay, dead branches and human-caused wounds. - Crown: dead wood, thin or undersized leaves, heavy limbs with weight concentrated at the ends - Trunk: cracks, cavities, cankers, bark that is coming loose - Branch unions: two stems of similar size joining at one point - Base and roots: fungal growth, soil cracks or heaving, lean that looks new ## Why does the ground and the site matter? The same defect matters more in some places than others. The ISA lists recent construction, changes in soil level and new lawn or pavement as questions to ask, because root loss from that kind of work can show up years later as a weak tree. Cracks or separations in the soil can warn of root movement, especially if the tree leans. For more on how site work hurts roots, see [protecting trees during construction](https://battleborntreeservice.com/guides/protecting-trees-during-construction/) and [trenching and grade changes near trees](https://battleborntreeservice.com/guides/trenching-and-grade-changes-near-trees/). ## What is a "target" and why does it change the answer? A target is whatever could be hurt or damaged if part of a tree fell: a house, a parked car, a play area, a driveway, a power line. A leaning pine in an empty back lot and the same pine over a bedroom roof carry the same defect but very different consequences. That is why an assessment is about more than the tree. The ISA notes that trees falling into utility lines can injure people and cause outages and fires. If any part of a tree is touching a line, stay back and call NV Energy. Never go near a downed line. ## What can come out of an assessment? The ISA brochure lists the usual options: prune the tree and remove defective branches, cable and brace to support weak branches and stems, provide routine care, or remove a tree whose risk is unacceptable. It adds that supports are not guarantees against failure. Most trees leave the assessment with a pruning recommendation, not a saw job. When removal is the answer, our [arborist consultation](https://battleborntreeservice.com/tree-services/arborist-consultation/) and [tree removal](https://battleborntreeservice.com/tree-services/tree-removal/) pages explain how the work is planned, and [crane-assisted removal](https://battleborntreeservice.com/tree-services/crane-assisted-tree-removal/) covers trees that cannot be dropped in pieces by hand. ## Who should do it, and when? The ISA recommends that anyone who answers yes to any checklist question have the tree examined by an ISA Certified Arborist. At Battle Born Tree Service, a certified arborist assesses every job before work begins, and we have two ISA Certified Arborists on staff. You can verify any arborist's credential on the ISA's Trees Are Good site. Do not wait for a storm. Look at your trees in calm weather, after a big wind, and after any digging or paving near them. If something worries you, call [775.232.8243](tel:775.232.8243) for a free estimate. If a tree is down on a house or anyone is hurt, call 911 first. ### Sources - [International Society of Arboriculture, Trees Are Good: Recognizing Tree Risk (brochure)](https://www.treesaregood.org/Portals/0/TreesAreGood_Recognizing%20Tree%20Risk_0721.pdf) (read October 17, 2026) - [International Society of Arboriculture, Trees Are Good: Mature Tree Care (brochure)](https://www.treesaregood.org/Portals/0/TreesAreGood_Mature%20Tree%20Care_0321.pdf) (read October 17, 2026) ### Talk to the office [775.232.8243](tel:775.232.8243) | Monday to Friday | 8:30 am - 5:00 pm | |---|---| | Saturday and Sunday | Office closed, phones answered | Phones answered seven days a week. 24-hour emergency service. [Free estimate](#quote) ### Keep reading - [Warning signs before a tree fails](https://battleborntreeservice.com/guides/warning-signs-tree-failure/) - [How to tell if a tree is dead or dying](https://battleborntreeservice.com/guides/is-my-tree-dead-or-dying/) - [Cabling and bracing: when it saves a tree](https://battleborntreeservice.com/guides/tree-cabling-bracing-explained/) - [Tree leaning toward the house: what to check](https://battleborntreeservice.com/guides/tree-leaning-toward-house/) - [Root and trunk decay](https://battleborntreeservice.com/tree-guide/root-and-trunk-decay/) - [Free estimate](https://battleborntreeservice.com/free-estimate/) ### Terms on this page [Arborist](https://battleborntreeservice.com/glossary/arborist/) [Codominant stems](https://battleborntreeservice.com/glossary/codominant-stems/) [The full glossary](https://battleborntreeservice.com/glossary/) ## More from the blog Pruning and care October 17, 2026 5 min read ### What should you do with your trees in October in Carson City and Reno? In October, finish watering while the ground is open, look over your trees for dead or hanging limbs, and clear leaves and needles away from the house. Save most live-wood pruning for the dormant seas Pruning and care October 17, 2026 6 min read ### Young trees in new subdivisions: the first ten years A young tree in a new subdivision needs very little pruning in its first two or three years, then steady structural pruning to build one strong central trunk and well-spaced branches. The ISA says tre Removal and equipment October 17, 2026 6 min read ### Where tree debris and green waste go in Reno and Carson City Green waste has a few legitimate homes in our area: the landfill or transfer station if the load is only wood and green waste, a fire district drop-off day or curbside chipping program if you qualify, [All posts](https://battleborntreeservice.com/blog/) ## Questions people ask Still have a question? Call [775.232.8243](tel:775.232.8243). Phones are answered seven days a week. ### Can an arborist tell me if my tree is safe? No honest arborist will call a tree safe. They can tell you what defects they found, how serious they look and what the options are to reduce risk. ### How often should my trees be looked at? The ISA suggests regular tree care so that defects are noticed early, and it recommends inspecting mature trees at least once a year for new growth, leaf size, twig growth and dieback. ### Does a crack always mean the tree must come down? No. A crack's seriousness depends on its size, location and what is underneath. That judgment belongs to an arborist on site. ### What if the tree looks fine but I just had construction nearby? Mention it. The ISA lists recent construction and soil changes as a warning sign even when the crown still looks healthy.