A very high percentage of homes that suffer hurricane damage will be the result of the roof and particularly the roof covering. Roof coverings, (i.e. shingles) loss will typically result in significant damage and loss the home or building. Once the shingles and waterproof membrane are removed water penetration and entry are easily obtained. Wind driven water can cause catastrophic damage to the walls, ceilings, and interiors of the home.
In order to properly evaluate the condition of the roof covering, the following conditions may indicate the need for repairs or replacement:
• Loose shingle tabs
• Cracks in shingles
• Broken or missing shingles
• Buckling or curling shingles
• Blistering tabs
• High granule loss to the shingles
• Open or loose seams
• The attic view indicating water staining or deck damage
• Home interior water staining on ceilings
To learn more about the proper installation practices for installing asphalt shingles, FEMA has published several guides that outline the roof underlayment and shingle installation for high wind regions. Asphalt Shingle Roofing for High Wind Regions, Technical Fact Sheet No. 20 and Roof Underlayment for Asphalt Shingle Roofing, Technical Fact Sheet No. 19. Much of the same information can normally be obtained from the shingle manufacturer or the paper wrapper for each bundle of shingles.
Roof Sheathing that is not properly nailed or secured to high wind standards can be “pulled off”. There are several methods that can be utilized to improve the strength of the roof deck attachment:
1. Upon new shingle installation, the use of more and longer nails for securing the roof decking to the rafters or trusses.
2. Interior roof deck attachment can be installed by accessing the underside of the roof via the attic. The use of foam sealant to the truss / deck junction will improve the wind uplift resistance of the roof sheathing.
Windows and Doors
Cracks around windows and doors are areas where large amounts of water can enter the building; even without structural failures. Protection of these areas, including sliding glass doors is very important. When gust wind speeds exceed over 120 miles per hour, one third of homes without window protection will suffer broken glass to at least one window. Older double entry French doors may burst open and allow wind and water to enter the home. Windborne debris is also a major cause for damage. Trees, older tile roofing materials and gravel can also be the culprits.
Installation of window and door shutters can greatly reduce damage and also insurance premiums. It is important to understand that opening protection standards need to meet certain criteria in order to be effective and also to meet insurance premium reduction standards. These protection products must be tested for impact resistance, pressure tested, and cycle testing for both positive and negative pressures.
Important standards, ratings, and approvals that the opening protection meets are:
Miami – Dade County Product Approval
Florida Building Code Product Approval
• SSTD12-93 / 97
• ASTM E- 1886 & E-1996
• TAS 201, 202, and 203
ASTM E-1886 refers to 9# Missile Testing. ASTM E- 1996 refers to 4.5# Missile Testing. Essentially this means that the product can withstand the impact of 4.5 lb. or 9 lb. object.
Window and door installation techniques and practices are an important aspect of maintaining an adequate resistance to wind resistance and water intrusion. Do not depend solely on the caulking and sealants to repel water entry. A systems approach must be incorporated in installing the windows and doors in conjunction with the secondary water barriers – i.e. housewraps and building papers. Additionally, the windows and doors must be adequately attached to the wall.
Leaking windows and doors are often the main culprit for water intrusion into the home. If these components are not properly installed a variety of issues will occur:
• wood decay
• fastener corrosion that will weaken the window and door frame
• water damage to interior finishes including mold growth
Detailed information about window and door installation is provided in the American Society for Testing and Materials (ASTM) standard ASTM E 2112, a comprehensive technical installation guide intended for use in training instructors who in turn train mechanics who actually perform window and door installation. The standard concentrates on detailing and installation procedures that are aimed at minimizing water infiltration. ASTM E 2112, Standard Practice for Installation of Exterior Windows, Doors and Skylights. Additionally, FEMA provides window and door installation guidelines, Technical Fact Sheet No. 21.
Garage Doors
About 80% of residential hurricane damage starts with wind entry through garage doors according to the Federal Alliance for Safe Homes. Many garage doors are made of lightweight materials to conserve weight and expense, which makes them vulnerable to high winds. The simple failure of a garage door can lead to catastrophic damage to homes and vehicles.
The hurricane season of 2005 provided much forensic data that revealed the following:
1. The negative-positive pressure of a hurricane causes a “tug of war” on the garage door, which is the largest entry to the house.
2. The garage door collapsed.
3. The attic entry in the garage ceiling collapsed, damaging vehicles below
4. The “tug of war”, negative and positive pressures collapsed the roof of the home.
Why Garage Doors Fail
Garage doors are only held in place by the rollers in the track. When the wind blows at the door, it creates positive pressure – the higher the wind speed, the greater the pressure. As the pressure increases, the door bows inward and the ends of the door are pulled toward each other (towards the center of the door), as well as causing the roller to tilt at an angle. Since the front of the tracks are flat, the rollers pull right out of the tracks and the door comes in as a unit and collapses. In negative pressure or suction, the garage door situation works in reverse. The door bows outward instead of inward. The more the door bows, the more the two ends are being pulled toward the center of the door. The track is curved in the rear so it rolls until the door is freed and is sucked out.
Since the wind direction can vary during a hurricane, garage doors must be protected against both positive and negative pressures. Hurricanes have cyclical winds and direction of the wind can be significantly different from the direction from which the hurricane is approaching depending upon where the home is located relative to the path of the eye of the storm. It is a fallacy to believe that since hurricanes may normally approach from the East, for example, that the east side of the home is more vulnerable and a West facing garage door does not require protection.
Wind rated garage doors protect against bowing by large horizontal beams, normally one per section or panel of the garage door. However, once the door is prevented from bowing, a second source of failure may exist. The tracks may pull loose from the home. Wind rated doors normally have heavier tracks than non rated doors and always have better systems for fastening the tracks to the wall more securely.
Soffit and Attic Ventilation
Vinyl and aluminum soffits are frequently installed so poorly that they are not able to resist positive and negative (suction) pressures created when wind speeds exceed 100 mph. Soffit damage can also occur in thunderstorms, especially to upper soffits on a two story house. When soffit panels become dislodged, strong winds can cause rain to blow up into the attic where damaging amounts of water can enter the home.
Ridge vents, off ridge vents, and gable end vents can allow a lot of water into the attic which can lead to the collapse of ceilings in homes that might otherwise look fine from the outside. There are products that can be purchased for the closure of these areas or a homeowner can improvise to temporarily install a closure over these areas. It is important to remember to remove these closures immediately after the storm, otherwise harmful side effects to the homes ventilation system will follow.
Gable End Walls
A gable end is a triangular wall that sits on a rectangular wall. Gable end walls will have to withstand a lot of wind forces during hurricanes and strong rainstorms. Gable end walls over five feet tall at the peak are a frequent area where damaged is concentrated. The roof sheathing may be lifted off at the gable end, which will open the attic to wind and rain. The bottom of the gable may break loose from the wall below. The members used to support the gable end wall exterior finish and / or their connections may fail. Typically, homes built prior to the early 1990’s may not have their gable ends properly anchored to the top of the wall below and the wall may not be properly braced.
The taller the gable end triangle, the greater the risk of damage. For gable ends that are shorter than approximately four feet, the forces applied by a 140 mile wind gust along the top and bottom of the gable end will be less than 100 pounds per cubic foot of gable width. Most nailed connections can handle these forces. It is very difficult to access the gable end if there is less than four feet in order to do any retrofit work. An important consideration in this circumstance is to determine if the roof sheathing is nailed or stapled to the trusses or roof rafters. In the event the sheathing is stapled, it would be prudent to re-nail the roof decking. A critical part of protecting your gable end from damage and keeping water out is to make sure the sheathing stays in place.
The most common type of gable end failures:
1. Loss of sheathing from the gable end that results in the gable wall losing its bracing along the top edge.
2. The connection between the rectangular and triangular walls
3. Actual framing members that make up the gable end wall structure. In many instances, these members are simply the structural members of the last roof truss. They are 2x4 lumber members that end up bent by pressure applied to the wide flat part of 2x4’s – the direction in which they are the thinnest and therefore weakest.
The Florida Division of Emergency Management, Bureau of Recovery and Mitigation, provides extensive information regarding Hurricane Retrofit Guides.
Alan Trauger is a Real Estate and Building Consultant for residential and commercial properties. Mr. Trauger has attained over 35 years of diversified experience and knowledge in construction, finance, and real estate. He has been involved in various facets of asset management, acquisitions, real estate work outs, property management, construction, inspection analysis, development, sales, leasing, and Ad Valorem tax appeal for over 25,000 single family and multi-family units and over 2.5 million square feet of commercial buildings. A Court Appointed Receiver and Expert Witness. An experienced and knowledgeable problem solver, understanding processes, and issues related construction and real estate.
Mr. Trauger’s wide spectrum of experiences, education, research, teaching, and publication of previous articles, commercial real estate market sales comparables, and textbooks enables him to assist property owners through the property assessment and tax appeal process.(alan trauger)
In order to properly evaluate the condition of the roof covering, the following conditions may indicate the need for repairs or replacement:
• Loose shingle tabs
• Cracks in shingles
• Broken or missing shingles
• Buckling or curling shingles
• Blistering tabs
• High granule loss to the shingles
• Open or loose seams
• The attic view indicating water staining or deck damage
• Home interior water staining on ceilings
To learn more about the proper installation practices for installing asphalt shingles, FEMA has published several guides that outline the roof underlayment and shingle installation for high wind regions. Asphalt Shingle Roofing for High Wind Regions, Technical Fact Sheet No. 20 and Roof Underlayment for Asphalt Shingle Roofing, Technical Fact Sheet No. 19. Much of the same information can normally be obtained from the shingle manufacturer or the paper wrapper for each bundle of shingles.
Roof Sheathing that is not properly nailed or secured to high wind standards can be “pulled off”. There are several methods that can be utilized to improve the strength of the roof deck attachment:
1. Upon new shingle installation, the use of more and longer nails for securing the roof decking to the rafters or trusses.
2. Interior roof deck attachment can be installed by accessing the underside of the roof via the attic. The use of foam sealant to the truss / deck junction will improve the wind uplift resistance of the roof sheathing.
Windows and Doors
Cracks around windows and doors are areas where large amounts of water can enter the building; even without structural failures. Protection of these areas, including sliding glass doors is very important. When gust wind speeds exceed over 120 miles per hour, one third of homes without window protection will suffer broken glass to at least one window. Older double entry French doors may burst open and allow wind and water to enter the home. Windborne debris is also a major cause for damage. Trees, older tile roofing materials and gravel can also be the culprits.
Installation of window and door shutters can greatly reduce damage and also insurance premiums. It is important to understand that opening protection standards need to meet certain criteria in order to be effective and also to meet insurance premium reduction standards. These protection products must be tested for impact resistance, pressure tested, and cycle testing for both positive and negative pressures.
Important standards, ratings, and approvals that the opening protection meets are:
Miami – Dade County Product Approval
Florida Building Code Product Approval
• SSTD12-93 / 97
• ASTM E- 1886 & E-1996
• TAS 201, 202, and 203
ASTM E-1886 refers to 9# Missile Testing. ASTM E- 1996 refers to 4.5# Missile Testing. Essentially this means that the product can withstand the impact of 4.5 lb. or 9 lb. object.
Window and door installation techniques and practices are an important aspect of maintaining an adequate resistance to wind resistance and water intrusion. Do not depend solely on the caulking and sealants to repel water entry. A systems approach must be incorporated in installing the windows and doors in conjunction with the secondary water barriers – i.e. housewraps and building papers. Additionally, the windows and doors must be adequately attached to the wall.
Leaking windows and doors are often the main culprit for water intrusion into the home. If these components are not properly installed a variety of issues will occur:
• wood decay
• fastener corrosion that will weaken the window and door frame
Detailed information about window and door installation is provided in the American Society for Testing and Materials (ASTM) standard ASTM E 2112, a comprehensive technical installation guide intended for use in training instructors who in turn train mechanics who actually perform window and door installation. The standard concentrates on detailing and installation procedures that are aimed at minimizing water infiltration. ASTM E 2112, Standard Practice for Installation of Exterior Windows, Doors and Skylights. Additionally, FEMA provides window and door installation guidelines, Technical Fact Sheet No. 21.
Garage Doors
About 80% of residential hurricane damage starts with wind entry through garage doors according to the Federal Alliance for Safe Homes. Many garage doors are made of lightweight materials to conserve weight and expense, which makes them vulnerable to high winds. The simple failure of a garage door can lead to catastrophic damage to homes and vehicles.
The hurricane season of 2005 provided much forensic data that revealed the following:
1. The negative-positive pressure of a hurricane causes a “tug of war” on the garage door, which is the largest entry to the house.
2. The garage door collapsed.
3. The attic entry in the garage ceiling collapsed, damaging vehicles below
4. The “tug of war”, negative and positive pressures collapsed the roof of the home.
Why Garage Doors Fail
Garage doors are only held in place by the rollers in the track. When the wind blows at the door, it creates positive pressure – the higher the wind speed, the greater the pressure. As the pressure increases, the door bows inward and the ends of the door are pulled toward each other (towards the center of the door), as well as causing the roller to tilt at an angle. Since the front of the tracks are flat, the rollers pull right out of the tracks and the door comes in as a unit and collapses. In negative pressure or suction, the garage door situation works in reverse. The door bows outward instead of inward. The more the door bows, the more the two ends are being pulled toward the center of the door. The track is curved in the rear so it rolls until the door is freed and is sucked out.
Since the wind direction can vary during a hurricane, garage doors must be protected against both positive and negative pressures. Hurricanes have cyclical winds and direction of the wind can be significantly different from the direction from which the hurricane is approaching depending upon where the home is located relative to the path of the eye of the storm. It is a fallacy to believe that since hurricanes may normally approach from the East, for example, that the east side of the home is more vulnerable and a West facing garage door does not require protection.
Wind rated garage doors protect against bowing by large horizontal beams, normally one per section or panel of the garage door. However, once the door is prevented from bowing, a second source of failure may exist. The tracks may pull loose from the home. Wind rated doors normally have heavier tracks than non rated doors and always have better systems for fastening the tracks to the wall more securely.
Soffit and Attic Ventilation
Vinyl and aluminum soffits are frequently installed so poorly that they are not able to resist positive and negative (suction) pressures created when wind speeds exceed 100 mph. Soffit damage can also occur in thunderstorms, especially to upper soffits on a two story house. When soffit panels become dislodged, strong winds can cause rain to blow up into the attic where damaging amounts of water can enter the home.
Ridge vents, off ridge vents, and gable end vents can allow a lot of water into the attic which can lead to the collapse of ceilings in homes that might otherwise look fine from the outside. There are products that can be purchased for the closure of these areas or a homeowner can improvise to temporarily install a closure over these areas. It is important to remember to remove these closures immediately after the storm, otherwise harmful side effects to the homes ventilation system will follow.
Gable End Walls
A gable end is a triangular wall that sits on a rectangular wall. Gable end walls will have to withstand a lot of wind forces during hurricanes and strong rainstorms. Gable end walls over five feet tall at the peak are a frequent area where damaged is concentrated. The roof sheathing may be lifted off at the gable end, which will open the attic to wind and rain. The bottom of the gable may break loose from the wall below. The members used to support the gable end wall exterior finish and / or their connections may fail. Typically, homes built prior to the early 1990’s may not have their gable ends properly anchored to the top of the wall below and the wall may not be properly braced.
The taller the gable end triangle, the greater the risk of damage. For gable ends that are shorter than approximately four feet, the forces applied by a 140 mile wind gust along the top and bottom of the gable end will be less than 100 pounds per cubic foot of gable width. Most nailed connections can handle these forces. It is very difficult to access the gable end if there is less than four feet in order to do any retrofit work. An important consideration in this circumstance is to determine if the roof sheathing is nailed or stapled to the trusses or roof rafters. In the event the sheathing is stapled, it would be prudent to re-nail the roof decking. A critical part of protecting your gable end from damage and keeping water out is to make sure the sheathing stays in place.
The most common type of gable end failures:
1. Loss of sheathing from the gable end that results in the gable wall losing its bracing along the top edge.
2. The connection between the rectangular and triangular walls
3. Actual framing members that make up the gable end wall structure. In many instances, these members are simply the structural members of the last roof truss. They are 2x4 lumber members that end up bent by pressure applied to the wide flat part of 2x4’s – the direction in which they are the thinnest and therefore weakest.
The Florida Division of Emergency Management, Bureau of Recovery and Mitigation, provides extensive information regarding Hurricane Retrofit Guides.
Alan Trauger is a Real Estate and Building Consultant for residential and commercial properties. Mr. Trauger has attained over 35 years of diversified experience and knowledge in construction, finance, and real estate. He has been involved in various facets of asset management, acquisitions, real estate work outs, property management, construction, inspection analysis, development, sales, leasing, and Ad Valorem tax appeal for over 25,000 single family and multi-family units and over 2.5 million square feet of commercial buildings. A Court Appointed Receiver and Expert Witness. An experienced and knowledgeable problem solver, understanding processes, and issues related construction and real estate.
Mr. Trauger’s wide spectrum of experiences, education, research, teaching, and publication of previous articles, commercial real estate market sales comparables, and textbooks enables him to assist property owners through the property assessment and tax appeal process.(alan trauger)
