Enhanced Fujita scale damage indicators and degrees of damage, chapter 9

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, increase toward upper-bound wind speed for Degree of Damage 5 (DODx) and DOD7

Table 9. Degree of Damage (DOD) for Expected (EXP), Lower Bound (LB) and Upper Bound (UB)
DOD	Damage Description	EXP*	LB*	UB*
1	Threshold of visible damage	105	85	130
2	Loss of roof covering (up to 20%)	125	105	160
3	Broken windows, including clear story windows or skylights	145	120	170
4	Exterior doors fail	160	130	190
5	Uplift of roof decking; significant loss of roof covering (more than 20%); loss of rooftop HVAC equipment	160	135	190
6	Collapsed façade or parapet walls	165	135	200
7	Uplift or collapse of entire roof structure	200	170	235
8	Collapse of exterior walls; closely spaced interior walls remain standing	230	200	265
9	Total destruction of entire building	255	240	320

*All wind speeds in km/h