Enhanced Fujita Scale Damage Indicators and Degrees of Damage

Small Professional Buildings: Single Storey, less than 500 m2 (SPB)

Typical Construction:

  • Flat, gable, hip, mansard or mono-slope roofs with or without parapet walls
  • Asphalt shingles, tile, slate, metal panels, single-ply or built-up roof covering
  • Light-frame steel construction, steel joists and formed metal decking
  • Load-bearing masonry construction with steel or wood roof structure
  • Timber post and beam construction
  • Wood or metal stud walls, non-bearing masonry walls
  • Metal or vinyl panels, stucco or EIFS cladding
  • Skylights and/or clearstories

Notes:

  • With hip roof, use upper bound wind speed for degree of damage 5 and degree of damage 7
Table 9. Degree of Damage (DOD) for Expected (EXP), Lower Bound (LB) and Upper Bound (UB)
DODDamage DescriptionEXP*LB*UB*
1Threshold of visible damage10587130
2Loss of roof covering (less than 20%)126105158
3Broken windows, including clear story windows or skylights143119172
4Exterior doors fail161132190
5Uplift of roof decking; significant loss of roof covering (20% or more); loss of rooftop HVAC equipment161135188
6Collapsed façade or parapet walls166137198
7Uplift or collapse of entire roof structure200169233
8Collapse of exterior walls; closely spaced interior walls remain standing232198266
9Total destruction of entire building253238322

*All wind speeds in km/h