In article ,
"Vaughn" wrote:

[snip]
Here in Florida, 90+% of the homes are built to the strict S. Florida
building code which (I believe) is based on surviving a 120 MPH wind, which is
only a mid-sized Category 3 hurricane. With a Category 4 hurricane you can
expect "...extensive curtainwall failures with some complete roof structure
failures on small residences". I believe a rough rule of thumb is that
damage
doubles for each additional 10 MPH wind speed. A class five hurricane has a
minimum wind speed of 155 MPH! You do the math.

Aerodynamic forces (lift and drag) vary as the square of wind speed, so
going from 120 mph to 150 mph raises the forces by a factor of
(150/120)^2= 1.56 to one.

Ref: http://www.av8n.com/how/htm/4forces.html

Joe Gwinn