Enhanced Fujita scale damage indicators and degrees of damage, chapter 8

Small Retail Buildings (SRB)

Typical Construction:

Flat, hip, gable, mansard or mono-slope roof
Asphalt shingles, metal panels, slate, tile, single-ply or BUR roof covering
Plywood/OSB roof decking
Wood or metal roof structure consisting of trusses or rafters and joists
Wood or metal stud walls
Typically have large areas of window glass and double entry doors
Canopies, covered walkways or porches
Wood, brick veneer, metal or vinyl siding, concrete blocks, EIFS or stucco wall cladding
Best example is fast-food restaurant

Notes:

With hip roof, increase toward upper bound wind speed for Degree of Damage 4 (DODx) and DOD6

Table 8. 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 glass in windows and doors	140	115	165
4	Uplift of roof decking; significant loss of roof covering (more than 20%)	160	130	190
5	Canopies or covered walkways destroyed	160	135	185
6	Uplift or collapse of entire roof structure	190	165	225
7	Collapse of exterior walls; closely spaced interior walls remain standing	220	195	255
8	Total destruction of entire building	270	230	310

*All wind speeds in km/h