Post-Tree Impact Structural Evaluation

Basic Fact Pattern
  • Large tree strike impact to the roof and stone walls of a historic home.
  • Home reportedly shook during the impact.
  • Tree limbs penetrated the clay tile roofing and the underlying roof structure.
  • The force of the tree strike into the home caused a portion of the trunk to split into two pieces.
  • Cracks and separations were noted throughout the home after the trike strike, including within the mortar joints of the historic stone walls.
Investigative Steps Taken
  • Photos of the tree on the home, as taken prior to the tree removal, were reviewed.
  • Comprehensive inspection of the home, including within the areas broken open by the tree impact, was conducted.
  • Doors and windows were operated throughout the home, along with measurements capable of detecting overall building movement.
  • All cracks, both interior and exterior, were photographed and mapped throughout the home.
  • Cracks were separated via in-field evidence into groupings of recent cracks and historic cracks.
  • Recent cracks were comparatively analyzed against the force load path from the tree strike locations to the ground.
Determinations Made
  • Structural roof members requiring repair were identified.
  • Wall elements with recent cracks consistent with the transfer of force through the structure from the tree strike were identified.
  • The cause(s) of the remaining cracks were also identified.
  • The overall structure had not experienced any global permanent movement in response to the tree impact force.
  • A scope of repairs was developed in accordance with applicable code requirements.
Involved Experts: 

more to read