Common Tree Defects That Increase Liability on Residential Properties

A tree does not need to look dead to be dangerous. Some of the most hazardous tree defects we encounter in the field are hiding in plain sight: a hairline crack along the trunk, a slight lean that developed after a storm, a cavity tucked behind a limb union. In short, hazardous tree defects are structural or health related weaknesses, such as cracks, decay, cavities, poor branch attachments, or root damage, that increase the likelihood a tree or a portion of it will fail. Recognizing them early is the difference between a manageable repair and a costly emergency.

Since 1984, our consulting practice has assessed thousands of trees across Palm Beach County and South Florida, and one pattern holds true across every property we visit: defects rarely announce themselves. This guide walks through the defects we look for most often, what they typically mean, and when it makes sense to bring in a certified consulting arborist for a closer look.

What Counts as a Hazardous Tree Defect

A defect is any feature of a tree’s structure or health that reduces its ability to withstand normal loads such as wind, rain, or its own weight. Not every defect is an emergency, and not every imperfect looking tree is unsafe. The goal of a proper tree risk assessment is to separate cosmetic issues from genuine structural concerns using an evidence based process rather than guesswork.

We generally group defects into three categories: those affecting the trunk, those affecting the crown and branch structure, and those affecting the root system. A tree can show a defect in one area and remain perfectly sound in the others, which is why a full evaluation matters more than a quick glance from the driveway.

Trunk and Stem Defects We Frequently See

The trunk carries the tree’s entire structural load, so defects here tend to carry more weight in a risk evaluation.

• Cracks and splits. Vertical cracks, especially ones that run deep into the wood or appear on both sides of the trunk, can indicate the tree is already failing internally. We pay close attention to cracks that open and close slightly in the wind.
• Cavities and decay pockets. Open wounds or old pruning cuts that never closed properly can allow decay fungi to enter. A visible cavity does not automatically mean removal is necessary, since trees can compartmentalize decay and remain structurally sound depending on how much healthy wood remains.
• Codominant stems with included bark. When two stems of similar size grow from nearly the same point, bark can become trapped in the union instead of forming a strong connection. These unions are a common failure point during hurricane force winds.
• Excessive lean. A tree that has always leaned slightly is often stable. A new or worsening lean, particularly one accompanied by soil heaving on the opposite side, is a different situation entirely and warrants a prompt inspection.

Crown and Branch Structure Defects

Above the trunk, we look for the same category of issues on a smaller scale.

• Deadwood and hangers. Dead branches lose flexibility over time and are more likely to break during wind events. Broken branches still caught in the canopy, sometimes called hangers, pose an immediate falling hazard.
• Poor branch attachments. Similar to codominant stems, weak branch unions with included bark are prone to splitting under load, especially on mature oaks and other large canopy species common throughout South Florida.
• Cankers and fungal conks. The presence of mushroom like fungal bodies (conks) on the trunk or major limbs often signals internal decay, even when the surrounding wood looks intact.
• Crown dieback. Thinning foliage or dying branch tips at the top of the canopy can point to root stress, disease, or girdling roots below ground, and it is frequently one of the first visible clues that something deeper is wrong.

Root System Defects

Root problems are the hardest defects to see and often the most consequential, since a compromised root plate affects the tree’s overall stability rather than a single limb.

• Girdling roots. Roots that circle around the base of the trunk instead of growing outward can slowly strangle the tree’s vascular system and destabilize it over years.
• Soil heaving or root plate lifting. Visible ground disturbance near the base of the trunk is one of the clearest warning signs of an unstable root system, particularly after heavy rain saturates the soil.
• Root damage from construction or trenching. Excavation for pools, driveways, or utility lines can sever a significant portion of a tree’s root system without any visible symptoms above ground for months or even years afterward.
• High water table stress. Much of South Florida sits on sandy or limestone based soil with a naturally high water table, which can limit root depth and make trees more prone to toppling in saturated ground during hurricane season.

Why These Defects Matter for Property Owners, Attorneys, and Insurers

For homeowners, an undocumented hazardous defect that later causes damage can raise questions of negligence. Florida courts have generally held that liability depends on whether a defect was reasonably foreseeable and whether the owner had constructive knowledge of it. That is exactly why we recommend documentation, not assumption.

For attorneys and adjusters, defect identification is the foundation of most tree failure disputes. Whether the question involves a fallen limb that damaged a roof or a root system blamed for foundation movement, our expert witness and forensic arboriculture work centers on identifying which defects were present, how visible they were beforehand, and whether the eventual failure was consistent with those findings.

For insurers, a documented defect history supports or challenges a claim far more effectively than a photograph taken after the fact. This is one of the main reasons our reports get referenced in insurance documentation work throughout Palm Beach County.

How We Evaluate Defects During an Assessment

When we inspect a tree for hazardous defects, the process generally follows ANSI A300 and TRAQ aligned methodology:

1. Ground level visual inspection, examining the trunk, root flare, and canopy from multiple angles.
2. Targeted testing when warranted, such as resistance drilling or sonic tomography to estimate the extent of internal decay without unnecessary damage to the tree.
3. Target and load assessment, considering what the tree could strike if a defect leads to failure and how often people or structures occupy that space.
4. Documented findings and recommendations, ranging from monitoring and pruning to cabling, bracing, or in some cases removal when a defect cannot be mitigated.

We do not diagnose or rate a specific tree’s risk without seeing it in person. Photographs and descriptions can suggest a possible concern, but an accurate evaluation of hazardous tree defects requires a hands on inspection by a qualified arborist.

Common Mistakes We See Property Owners Make

• Assuming a tree is safe simply because it still has green leaves.
• Waiting until after a storm to schedule an inspection rather than before hurricane season.
• Attempting to assess internal decay or root health without professional tools.
• Hiring a tree removal company to evaluate whether removal is necessary, which creates an inherent conflict of interest.

That last point is worth underscoring. As an independent consulting arborist, we have no financial stake in whether a tree is pruned, cabled, or removed. Our recommendations are based strictly on what the evidence shows, which is a distinction attorneys, adjusters, and homeowners have come to rely on.

When to Schedule an Inspection

Every property and every tree is different, and the only way to know for certain whether a defect is hazardous is a hands on inspection. As a general guide, we recommend scheduling an evaluation if you notice a new or worsening lean, visible cracks, fungal growth on the trunk, recent construction near the root zone, or significant crown dieback, and as routine preventive practice ahead of hurricane season each year.

For more information on defect identification standards, the International Society of Arboriculture publishes guidance on tree risk assessment methodology that informs much of our field approach.

Final Thoughts

Hazardous tree defects rarely appear overnight, and most of the failures we investigate after the fact show warning signs that were visible well before the storm that finally brought the tree down. Since 1984, Arborist Consulting Solutions has helped property owners, attorneys, and insurance professionals throughout Palm Beach County and South Florida understand the condition and risk of the trees on their property. Every tree and every property is different, and the details matter. If you have noticed a crack, a lean, or a change in a tree’s canopy and want an informed second opinion, our team is happy to talk it through and schedule an on site assessment.