Wind Speed vs. Wind Pressure Explained

Many who don’t understand how wind works will state a product is rated to a specific wind velocity which is false advertising and not true. “Rated to 180 MPH wind” is frequently seen in marketing materials which is a false and misleading statement that comes with many unwritten disclaimers.   The formula that converts wind velocity to…

How do I tell if my building is considered “enclosed”?

A building is considered “enclosed” if it does not comply with the requirements for open or partially enclosed buildings (ASCE 7-10, Section 26.2, “BUILDING, ENCLOSED”).   From the ASCE 7-05 Commentary   BUILDING, ENCLOSED, OPEN, PARTIALLY ENCLOSED: These definitions relate to the proper selection of internal pressure coefficients, GCpi . Building, open and building, partially enclosed are specifically…

How do I calculate the effective opening area on window or door products? – What opening area should be used for wind pressure determination on a multi-panel product?

The Building Codes in the US reference ASCE-7 for the design of the components and cladding of buildings (26.1.2.2 ASCE 7-(10)).  The theory of wind design goes that the smaller the area in consideration, the greater the probability that a maximum burst of wind will occur in that area over any 3 second period.  Wind…

ASTM E1996 Missile Levels and Definition

Missile Level E 6.2.1.1 Enhanced Protection (Essential Facilities): Buildings and other structures designated as essential facilities, including but not limited to hospitals, other health care facilities having emergency treatment facilities, jails and detention facilities, fire, rescue and police stations, and emergency vehicle garages, designated emergency shelters, communications centers and other facilities required for emergency response,…

The Recently Updated Saffir-Simpson Scale

First, it needs to be said that there is a complicated formula that converts wind velocity to wind pressure.  Many wind pressure values can exist from a single wind velocity which vary based on roof height, topography, terrain, even code version, and more.  See our wind speed to wind pressure calculators for different ASCE codes by…

What wind speed should I use for my project?

The answer to that question varies with location and type of building, but feel free to download the attachment listed below which is an exhaustive list of the wind speeds used in the general Florida locale and another general map for the country. Please be sure to verify with your local Building Department as these…

Should a professional utilize the ASD (“Allowable Stress Design”) method or the LRFD (“Load Resistance Factored Design”) method when calculating the required wind pressure for use with tested / approved systems?

Most all products are evaluated using the ASD method (unless noted otherwise). ASD method in, then ASD method out. Among the notable changes in ASCE 7-10, the wind speed map and the importance factor for wind loads have been replaced with three wind load maps based on difference and newly defined return periods and for…