Protecting infrastructure from Protecting infrastructure from hurricanes:hurricanes:
Lessons learned about the importance and effectiveness of adopting and following modern
building codes
Tim Reinhold
Institute for Business & Home Safety
Design Standards for Manufactured Design Standards for Manufactured HousingHousing
Pre- 1976– No standards, lots of singlewides– Generally very poor performance
1976-1994– HUD Code, more doublewides– Two design levels – not tied to modern wind std.– Better performance but lots of damage
Post 1994– Wind zones 1-3– ASCE 7-88 loads and wind map– Clearly superior performance
Strengthening Codes Works
Attached StructuresAttached Structures
New Commercial Structure in Punta Gorda
Older Commercial Structure across street in Punta Gorda
Windborne DebrisWindborne Debris
Primary Sources: Roofing Materials Siding Materials Vegetative Debris Structural
Components Unsecured Items
(Patio Furniture, Potted Plants, lawn ornaments, etc.)
Elimination of Gravel BallastElimination of Gravel Ballast
Debris and Internal PressuresDebris and Internal Pressures
Punta Gorda City Hall & AnnexPunta Gorda City Hall & Annex
Mitigation Success– Annex in use– City Hall gutted
Aggregate Losses for Charlotte Aggregate Losses for Charlotte County and Punta GordaCounty and Punta Gorda
All Building Permits: $1.8 BillionResidential Garage Doors: $2.6 MillionShingle Roofs: $114 MillionTile Roofs: $87 MillionResidential Cages: $16 Million
Roof covering and soffit Roof covering and soffit failures lead to interior damagefailures lead to interior damage
Roof Covering Failures - TileRoof Covering Failures - Tile
Tile Roof Damage Tile insufficiently attached to
roof deck:
Continuing Problems: Continuing Problems: Garage Door FailuresGarage Door Failures
Failed primarily due to lack of reinforcement and track bracing for design pressures
Some were also damaged by windborne debris
Continuing Problems:Continuing Problems:Double Entry DoorsDouble Entry Doors
Continuing Problems:Continuing Problems:Gable EndsGable Ends
Gable End Failures– Sheathing loss– Un-braced gables
Reducing Hurricane Risks & LossesReducing Hurricane Risks & Losses
ConclusionsConclusionsBuildings built under the latest codes
where enforcement was good – generally performed well structurally (some exceptions)
Keys are:– Good up to date code– Uniform and thorough enforcement– Builders and subs who understand and
appreciate the risks– Special inspections for key functions
Benefit-Cost Studies for Benefit-Cost Studies for Building CodesBuilding Codes
Texas A&M Study for TDI Code– For individual provisions large variability– For system of provisions B-C ~ 4 to 7
Seismic Code Study for Utah and LA– B-C of 4.3 for Utah– B-C of 6 to 16 for LA
RecommendationsRecommendations
Appropriate funds for National Windstorm Loss Reduction Program authorized last year
Increase support for NOAA / FEMA in wind field modeling
Increase support for NOAA in hardening and backing up ASOS stations
Add incentives for code adoption and enforcement
Add incentives for mitigation