About half of structural losses sustained during windstorms are caused by falling trees, with annual losses estimated to be between $3 billion and $5 billion. More than three-fourths of trees that fell during a weather event showed signs of a pre-existing and often correctable condition that made them vulnerable.
Routine maintenance of large trees is a critical component of any loss prevention program, particularly in wind-prone areas. While assessing the risk, homeowners need to ask themselves some key, and often tough, questions: Has that tree outlived its usefulness? What would happen if it fell on the house or on the neighbor's house or into a busy street? Does the cost to remove the tree outweigh the risk of leaving it be?
You trees may need a health checkup. The good news is many tree health issues are correctable without removal.
Here are some of the less easily recognized signs of poor tree health:
- Root damage: Damage to roots is most easily detected above ground. Signs include branches that start dying at the tip or trunks that lean enough to need bracing.
- Co-dominant stem: A tree with two main trunks is structurally unstable and at a high risk of failing.
- Excessive lean: Many trees lean, but those with evidence of root lifting, soil mounding, cavities, cankers or decay are cause for concern.
- Wounds: Trees attempt to close and compartmentalize wounds, but cavities, cankers or decay on more than 40% of the circumference can affect stability.
- Longitudinal crack: Longitudinal cracks, especially ones that start at a branch union, can be dangerous.
- Recent excavation within the drip-line: Excavation or construction within the drip-line damages feeder and anchoring roots, which weakens a tree, increases its susceptibility to disease and insects and makes it less stable and resistant to wind.