Bernoulli’s Principle and How High Winds Destroy Rooftops
We all remember the last series of hurricanes that blew through the Caribbean and hit the United States in the fall of 2017: Harvey, Irma, and Maria, among others. And, if you lived in those areas, you probably remember quite vividly the extent of the damage and the number of homes affected by such force of nature which was accompanied by storm surge and high winds.
However, once a structure has been wrecked, it’s very difficult to determine the exact sequence of events that lead to its destruction. Because a homeowner’s insurance policy might cover damages caused by wind and in other those provoked by water, it becomes necessary to be able to determine what natural phenomenon is responsible for which damage. In many of those cases, engineering and meteorological personnel had to be called in to file reports of exactly what happened to a particular structure that suffered damage during a hurricane.
Generally, wind damage tends to be most severe at the roof and upper walls of a structure, chiefly near leading edges where wind pressures are greatest. On the other hand, storm-surge damage tends to be most severe near the base of a structure due to the effects of rising water and its accompanying waves. When water rises quickly, homes become susceptible to floating off their foundations before water levels are able to equalize. These residences may move in one piece or may break apart. Walls can collapse and the whole roof structure may move away from its original resting place.
Yet, this type of damage is not the only one responsible for the destruction of roofs. What about high winds? You may think that, since water is roughly 800 times as dense as air, very little water speed is needed to exceed the pressures exerted by even a strong wind and therefore it is most likely that almost all damage and destruction is caused by water.
High Winds Do Destroy Rooftops
Windstorms are definitely a major source of hazard because when the velocity of the wind is great enough, the air pressure above the surface of the roof is lower than that underneath it. This causes the roof to blow off.
This happens as a result of the Bernoulli effect. The Bernoulli principle states that an increase in the speed of a fluid (or a gas, in this case) happens simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy. This principle is named after Daniel Bernoulli who explained it in great detail in 1738 in his book “Hydrodynamica.” Despite the fact that Bernoulli assumed that pressure decreases when the flow speed increases, it was Leonhard Euler who, in 1752, developed Bernoulli’s equation as we know it today. In short, the wind crossing the surface of a roof gives it lift. If the wind is high enough, part or all of the roof can be torn away.
Your Roofing Contractor In Portland Can Help Rebuild Or Restore Your Roof
You don’t need to have gone through a hurricane and have your roof blown off to require fixing or improving your roof in a city like Portland. In some cases, replacing or repairing a few shingles might be all that is needed to have your roof looking like new. Protect your home’s integrity and give your family the comfort they deserve by having your roof looked at by a roofing contractor in Portland.
