The Applied Technology Council (ATC) offers site-specific information that is used in our calculators to determine the wind velocity. For the best results, the address of the site may be used. To find your wind speed, follow the step-by-step guide below. Navigate to https://hazards.atcouncil.org/#/ Enter your address, zip code, or city and state in the search…Details
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…Details
ASCE 7 separates wind loading into three types: Main Wind Force Resisting System (MWFRS), Components and Cladding (C&C), and Other Structures and Building Appurtenances. MWFRS is defined as “(a)n assemblage of structural elements to provide support and stability for the overall structure.” Typically, members which receive loading from two surfaces are designed to resist MWFRS…Details
If you’d prefer to hear this in Spanish, use the video below. Si prefiere escuchar esto en español, utilice el siguiente vídeo.Details
The directionality factor (Kd) used in the ASCE 7 wind load provisions for components and cladding is a load reduction factor intended to take into account the less than 100% probability that the design event wind direction aligns with the worst case building aerodynamics. Per ASCE 7-10,Section 26.6, the Directionality Factor Kd is defined…Details
Per ASCE 7-10, buildings are composed of 5 different zones, depending on the wind loading they are subjected to. These zones are defined as follows: Zone 1: Has the lowest load; this zone accounts for approximately 80% of the roof surface, represented in the interior zones of the roof. Zone 2: Higher loading than Zone 1; this…Details
Per ASCE 7, the Mean Roof Height (h) is defined as the average of the roof eave height and the height to the highest point on the roof surface, except that, for roof angles of less than or equal to 10°, the mean roof height is permitted to be taken as the roof eave height. Visually, AAMA TIR A15-14…Details
Note: Updated March 2018 in response to 3 negative user feedback comments for more information. Please thumb this up! A canopy is a structure which provides overhead protection from the elements such as rain, snow, or sunlight. Canopies can be attached to a structure or they can be free standing with their own supports. They…Details
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…Details
A building is considered open if each wall is at least 80 percent open (ASCE 7-10, Section 26.2, “BUILDING, OPEN”). This condition is expressed for each wall by the equation Ao ≥ 0.8 Ag where Ao = total area of openings in a wall that receives positive external pressure, in ft2 (m2) Ag = the…Details
A building is considered “Partially Enclosed” if it complies with both of the following conditions (ASCE 7-10, Section 26.2, “BUILDING, PARTIALLY ENCLOSED”): the total area of openings in a wall that receives positive external pressure exceeds the sum of the areas of openings in the balance of the building envelope (walls and roof) by more…Details
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 (18.104.22.168 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…Details
From the 5th Edition of the Florida Building Code (2014) section 1603.1.4 and from section 1603.1.4. of the 2012 International Building Code, construction documents shall show the following: Ultimate design wind speed, Vult (3-second gust), miles per hour and nominal design wind speed (Vasd) as determined in accordance with code section 1609.3.1 Risk Category…Details
In the 5th Edition Florida Building Code (2014), missile level E is valid in and outside of the HVHZ (Broward and Dade Counties) when it came to essential facilities. Sure it is in section 1626.2.4 of the FBC which falls under HVHZ but section 422.214.171.124.1 refers to 1626. In previous codes it was in section 419…Details
About Exposure D Exposure ‘D’ is a multiplier when converting wind velocity to wind pressure that represents coastal areas. It’s used in many formulas in ASCE 7-10 for wind, a larger topic than we can cover here. Non coastal areas have Exposure categories B and C. Exposure D is a moving target from the coastline…Details
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…Details
Did the loading requirements change for rooftop structures for ASCE 7-10 and the 2014 Florida Building Code?
YES. The loading requirement of “Rooftop Structures” has been revised in ASCE 7-10. Essentially, buildings less than 60-ft still have the requirement that their wind load be multiplied by a GCr factor applied to the wind pressure that can be as high as 1.9. This has been in place since the 2007 version of the…Details
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…Details