Hurricane Damage Mitigation for Homeowners

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Hurricane Damage Mitigation for Homeowners
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What Well Talk About

• Hurricanes in Virginia - How Likely?- How Strong?
• Protecting Your Home From Hurricane Hazards
• Wind and Windborne Debris
• Rain
• Storm Surge and Waves
• Resources for More Detailed Information

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The Saffir-Simpson Damage Potential Scale
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U.S. Direct Hits (1900-1996)
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Historical Hurricane Tracks
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Hurricane Wind Distribution
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Hurricane Isabel
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Hurricane Floyd
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Hurricane-Force Winds

• Of all the hazards associated with hurricanes,
  wind causes the most widespread damage

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Hurricane-Force Winds

• are more turbulent than most other wind storms
  (tens of thousands of gusts)
• are sustained for longer periods of time (hours)
• change slowly in direction, seeking out the most
  critical angle of attack
• carry large amounts of debris

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Anatomy of a Destroyed Home

• The roof fails or gable-ends collapse
• Lost windows and doors contribute to failure
• With the roof lost, walls collapse

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Finding the Weak Point

• Failure is progressive
• The weak point fails first
• Further failure becomes more likely

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Every House has a Weak Point

• Design Goal - 156 mph Wind Survival
• As Built - 137 mph Survival
• Whats the Weak Point?

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Protecting Your Home from Wind Damage

• Strengthen the Roof
• Reinforce Gable-Ends
• Ensure Proper Connections
• Protect Openings
• Eliminate Debris Sources

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Keeping the Roof On

• Proper Sheathing Attachment
• Gable-end Reinforcement
• Continuous Load Path to Ground

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Gable-End Bracing

• Gable-end failure can lead to roof failure
• Gable-ends can be easily reinforced

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The Continuous Load Path

• Holds the Envelope Together
• Transmits Hurricane Forces to the Earth

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The Re-Roofing Opportunity

• Re-Roofing is the best opportunity to
  significantly strengthen the home again wind
  damage
• Install hurricane straps
• Re-nail roof sheathing and/or use adhesives
• Install a secondary water barrier and/or tape
  joints
• Install properly attached shingles

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Re-Roofing
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Windborne Debris

• Debris causes a large fraction of damage
• Size increases with wind speed
• Windows and doors are especially vulnerable

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Protecting from Windborne Debris

• Eliminate Sources of Debris
• Secure out-buildings
• Remove unsecured items from around the house
• Remove trees within falldown distance
• Protect Openings
• Especially garage and patio doors

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Protecting Openings

• The Most Vulnerable Openings
• Double-Wide Garage Doors
• Patio Doors
• Windows
• Double Entry Doors

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Hurricane Rain

• Torrential
• Floyd 20
• Isabel 11
• Wind-Driven

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Protecting from Rain Damage

• Roofs have three lines of defense again rain
  intrusion
• Shingles
• Underlayment
• Roof Sheathing
• Routine re-roofing is an excellent opportunity to
  significantly increase roof water resistance

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Storm Surge and Waves

• Surge - a steady rise in sea level
• Waves are on top of surge
• Elevation is key to home survival

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Waves

• Waves are on top of surge
• Hazards
• Direct Wave Action
• Waterborne Debris
• Erosion

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Protecting Homes from Waves and Flooding

• Elevation is the Key to Survival
• Properly Embedded Piles
• Continuous Load Path

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If Youve Got 300 to Spend

• Clean the Yard of Debris Sources
• Brace Gable-End Walls
• Use Extra Nails when Re-Roofing Even Better, Use
  Screws
• Reinforce Garage Doors

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If Youve Got 1,000 to Spend...

• Build or buy plywood covers for all windows and
  patio doors
• Replace double garage doors with hurricane
  load-tested doors

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If Youve Got More Than 1,000 to Spend...

• Re-do the Roof to Wind-Resistant Standards
• Install Hurricane Straps
• Install Hurricane Shutters

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Summary

• Homes Can Survive Most Hurricanes if Properly
  Constructed or Retrofitted
• Eliminate debris sources
• Reinforce the roof and gable-ends
• Protect openings
• Elevate the home above flood level

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Recommended Publications

• Is Your Home Protected from Hurricane Disaster?
  (www.ibhs.org)
• Blue Sky High Wind Consumer Guide
  (www.bluesky-foundation.net)
• FEMA Documents (800-480-2520)
• Hurricane Andrew In Florida - FEMA FIA-22
• Coastal Construction Manual - FEMA 055
• Taking Shelter from the Storm - FEMA 320

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Whats the Weak Point?

• The Garage Doors
• Only rated to 137 mph

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More Questions?

• Jon Ayscue
• Disaster Field Office
• 7800 Carousel Lane
• Richmond VA 23294
• Phone [phone]
• Fax [phone]
• Email jon.ayscue_at_dhs.gov

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Hurricane Damage Mitigation for Homeowners