Enhanced Fujita scale damage indicators and degrees of damage, chapter 17
Low-Rise Buildings: 1-4 Storeys (LRB)
Typical Construction:
- Generally consist of rectangular modules but can be “odd shaped” in plan-view sense
- Most will have flat roofs but can have gable, hip or mansard shapes
- Roofing materials include BUR, single-ply membrane, metal panels or standing seam
- Roof deck is wood or metal deck, poured gypsum deck or concrete slab
- Steel or reinforced concrete structural frame
- Glass and metal curtain walls, metal studs with EIFS, non-bearing masonry walls with stucco or brick veneer
- Examples are office buildings, medical facilities, and bank buildings
Notes:
- With hip roof, increase toward upper-bound wind speed for Degree of Damage 3 (DODx) and DOD5
| DOD | Damage Description | EXP* | LB* | UB* |
|---|---|---|---|---|
| 1 | Threshold of visible damage | 110 | 90 | 135 |
| 2 | Loss of roof covering (up to 20%) | 130 | 110 | 165 |
| 3 | Uplift of metal roof decking at eaves and roof corners: significant loss of roofing material (more than 20%) | 165 | 135 | 195 |
| 4 | Broken glass in windows, entryways or atriums | 165 | 135 | 195 |
| 5 | Uplift of lightweight roof structure | 215 | 185 | 255 |
| 6 | Significant damage to exterior walls and some interior walls | 230 | 195 | 270 |
| 7 | Complete destruction of all or a large section of building | 305 | 260 | 355 |
*All wind speeds in km/h