Wind damage really sucks – literally – in a hurricane
Remember Lisanby v USAA? What I remember most is the engineering professor saying he’d flunk a student that looked at the pictures and didn’t know the wind caused the first floor damage.
The Lisanby home was damaged by the wind loading to the house…the roof was subjected to uplift from the wind and the interior of the house to a “tunneling effect.
Automatic F for me although I’d seen enough of Katrina’s damage not to doubt. However, after my research today I might skate by with a D – but I think I’d pass (barely).
Winds flowing over exterior surfaces create suction, pulling walls and roof outward. Loss of windows or doors allows wind to enter and increases outward pressure.
Wind affects different homes in different ways, depending on their design, location and neighboring structures…With or without the help of wind-blown objects, the wind can break through a garage door, window or door on the windward side of the house and move inside, causing uplift forces to more than double. In fact, these powerful forces, which are illustrated below, can literally lift the roof right off the house….
Among other things, the wind can collapse windows and doors, rip off roof sheathing (decking) and destroy gable end walls. Overhanging eaves and rakes, extended awnings, open porches and other features that tend to trap air beneath them are particularly susceptible to damage.
In other words, wind blows but it sucks, too. Wind suction turns your umbrella upside down and pushes your sailboat across the water. In one of the videos we recently received and posted, you could see the impact of wind on a flat roof.
As this patent application explains, what we were seeing was the wind sucking the roof off although it seemed as if the pieces were just being blow away.
Windstorm related losses average several billion dollars annually. Roof covering failure, in particular, is a widespread type of damage observed after hurricanes. Once an area of the roof is damaged, building and home interiors are exposed to further damage from inclement weather.
The focus of concern, here, is the damage caused to flat top or shallow pitched roofs of buildings due to high winds associated with a storm regardless of the particular meteorological designation of the storm. High winds cause unwanted roof suctions that can severely damage or completely destroy the roof as well as the building structure.
So, the answer my friend isn’t blowing in the wind – it’s sucking – and then the water comes and washes all the evidence away. The song definetly sounds better the other way – it just won’t hold up in court.