Protecting infrastructure from hurricanes: Lessons learned about the importance and effectiveness of...

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