Wind, Hail, Storm Damage

Wind, Hail, and Storm Damage


The peril of windstorm involves damage caused by direct action of the wind, including high winds, tornadoes and hurricanes. Windstorm damage to an exterior is usually evident, there is often a question to the structural integrity of a building.  Frequently, water damage inside a structure is often claimed as a result of wind driven rain.  Cissell Investigative Engineering LLC (CIE) checks the weather for the area, particularly sustained maximum winds and gust velocity and their direction.  We also determine if the storm produced other evidence of high winds in the area.

Wind must reach sufficient velocity to have caused direct damage at more than one location to establish a “windstorm” loss. Basement flooding and leaks through an aged roof are not a windstorm loss. Although windstorm peril may not cover losses to  items outside of the insured building: awnings, signs, plants, shrubs or trees, we observe them and document them as an indicator of a windstorm.

When we find windstorm related water intrusion it is often the result of recent poor workmanship and/or product liability issues.  If similar work was done on the property, CIE checks for hidden conditions similar to the loss sustained.


Although the New England area is not widely known for large hail storms, CIE encounters these claims routinely.  Hail is formed in thundercloud cells, cumulonimbus,  updrafts carry rain higher into the cloud where it freezes and drops and can pick up more rain and then be caught by another updraft, sometimes this cycle occurs several times and results in large hail stones.  Eventually the hail falls and can cause severe damage.  Fortunately, the thunder cells in New England infrequently produce hail of sufficient size to cause damage.

CIE evaluates these claims through several methods, forensic meteorologists are consulted as needed, but often we only need to look for the patterns consistent with hail strikes.   Hail damage has an escalating profile depending on the size of the hail.  Patterns of damage for the lesser profiles must accompany major damage.


0.5″ – bushes and leaves stripped, “skid” marks on siding where hail removes oxidation

0.75″ – threshold damage to rolled roofing, some denting to flashing and thin metal surfaces

1.0″  – threshold damage to composite shingles, vinyl siding, windows and thin skylights damaged

1.25″ – auto’s light damage, heavy shingles damaged

1.5″ – heavy auto damage, wood shakes damaged


Lightning is “naturally generated electricity from the atmosphere.” Damage covered by the lightning peril may be the result of lightning itself or the result of a fire caused by the lightning.  Lightning produces several common effects:

  • Direct discharge – usually pretty obvious
  • Ground current surge – this effect is caused by the movement of electrical ions in the ground that flow towards the ground strike.  Wires within this area has an induced current caused by the electrical flow of ions and can often affect building wiring.  We’ve observed several fires caused by this phenomena.  Well pumps have large runs of wire in the ground and often will be the conduit into the buildings electrical panel.
  • EMP – electro-magnetic pulse is found emanating from the strike and frequently affects microprocessors
  • Electrical surges caused by power company equipment failures from strikes.  If the failure is purely from a power company equipment failure, some policies do not cover.

Weight of Ice, Sleet, and Snow

The most common problem encountered are trees that fall impacting the roof and affecting the structure much like an earthquake shock.  The ensuing damage often affects areas outside the immediate impact area.  Snowloads can trigger a collapse of a weakened  or overloaded structure.

CIE has found many structures affected by abnormal loads that contributed to failure.  The engineering comes in to assess the proximate cause of the loss, was the load abnormal, was there decay, poor construction, inadequate support or any of a number of multiple considerations.  One failure that we examined occurred when a moderate ice and snow load fell 15′ onto a new addition, collapsing the structural panel roof, a foreseeable event in New England.  The contractor was identified as a subrogation target as there was no protection afforded against falling snow.

As professional engineers, if we detect a condition that may be in imminent danger of collapse we inform the insured and often make recommendations on how to temporarily support the structure against further collapse.


Adjusters often miss opportunities for investigating the cause of a freeze-up.  We frequently find cause for filing a subrogation claim against a responsible party and have had numerous successful construction defect recoveries.  Some firms send a boiler technician to examine a boiler as the proximate cause.  Cissell Investigative Engineering LLC (CIE) sends an engineer that is trained to examine boilers, all too often we find the cause an insulation problem, no heat and delivery issues.  We take surface temperatures of walls and floors and examine thermographs and furnace operation; coupled with weather, water and fuel records we’re able to determine, with confidence, the times of freeze-up and thaw.  Was the oil delivery timely?  Did the furnace/boiler flame out while on vacation?  Was the house vacant?  Was there sufficient heat?  Are there insulation problems?  The most common problems we find are with construction problems.

CIE’s engineers have the prerequisite HVAC, heat transfer, energy audit experience to quickly and confidently determine the cause.

Updated: August 1, 2014 — 12:22 pm

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