Introduction

The most important actions that can be taken to reduce damage to a home and its contents is to protect the areas where wind and water can enter. According to research into hurricane induced damage, it is important to strengthen the exterior of the house so wind forces and debris impacts do not create large openings and so that wind driven rain does not cause damage. This is done by protecting and reinforcing these six critical areas:

• Critical Areas

o roof covering and deck attachment

o windows and skylights

o doors, including garage doors

o anchoring of roof structures to walls including porch roof attachment

o soffits and attic vents

o gable end walls

Once the critical areas are addressed and improved, there are several additional considerations to further reduce the potential for damage:

• Additional areas to be considered

o aluminum structures

o surrounding area

Roof Coverings: Roof covering damage is observed in 95+ percent of all homes that suffer significant damage and loss.

Roof Sheathing: Wind can pull sheathing off roofs when the sheathing is not nailed to high wind standards.

Windows and Glass Doors: When gust wind speeds climb above 120 mph, about one third of homes without window protection, suffer broken glass to at least one window.

Entry Doors: When gust wind speeds climb above 120 mph, older (not current code approved) double entry doors may burst open, allowing wind and water to enter the home.

Garage Doors: Garage doors that are not designed for current pressure and/or impact requirements frequently fail as gust wind speeds climb above 120 mph.

Anchorage of Roof Structure: Homes that lose the entire roof frequently don’t have hurricane straps holding down the roof structure and almost always have a window or a door that is broken open on the windward side of the home, which has allowed wind pressures to increase significantly inside the house.

Soffits: Vinyl and aluminum soffits are frequently installed so poorly that they are not able to resist positive and negative (suction) pressures created when gust wind speeds exceed about 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 house.

Attic Ventilation: Ridge vents, off ridge vents and gable end vents can let a lot of water into the attic which can lead to the collapse of ceilings in homes that otherwise look fine from the outside.

Gable End Walls: Gable end walls over 4-feet tall at the peak are a frequent area where damage is concentrated. The roof sheathing may be lifted off at the gable end, opening up the attic to wind and rain. The bottom of the gable wall 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, houses built in areas where the high wind building code provisions developed in the early 1990’s have not been adopted and followed, have gable end walls that are not properly anchored to the top of the wall below and the wall has not been properly braced. If this wall and/or gable end is pulled away from the house by the wind, it will open up the entire end of a house.

Additional Areas to be considered

Porch Roofs: Most porches and overhangs are poorly anchored and can get torn off the house, causing damage that extends well into the house. In many cases this will result in catastrophic damage to the house. The uplift forces on these wing-like roofs can be tremendous compared to the ability of their supporting posts, and especially the connections to the posts, to hold them down. Don’t be deceived by seeing straps or other connectors. They are frequently undersized and should be checked for adequacy.

Aluminum Structures: Aluminum structures such as carports and pool enclosures are often inadequately anchored, braced and connected. They are often the first structures to be blown down and then blow into a house.

Surroundings: While nearby buildings may help break up the wind by acting as shields, they can also channel the wind so that it becomes more intense in some areas. Furthermore, other buildings can be a source of debris that is picked up by the wind and hurled at windows and doors. As long as trees are still standing, they can have an overall calming effect by slowing down the wind near the ground. However, they can also be a source of trouble by shedding branches which become windborne debris and if they are too close they can fall on the house. Tall pine trees are one of the most dangerous sources of tree damage as they have often sliced through roofs and walls. However, the fact that an oak tree has survived for a century or more is no guarantee that it will not fall on the house. It has been seen many, many times.