This is an Archive of the ASCE7-05 Windload Program for Wall Components and Cladding

The program is officially decommissioned and removed December 2025. Please go to the newer codes: ASCE 7-22 Wind Load calculator

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To get started select and enter your project information.

Wind speed =

From Figure 6-1

Importance Factor I=

Defined from Table 6-1, page 77

Building Exposure =

Defined from 6.5.6, page 25

Internal Pressure Coefficient =

From Table 6-5, page 47

Roof Angle =

From Figure 6-11, page 55

Kzt =

Kzt default = 1.00

Refer to section 6.5.7.2 and figure 6-4 to determine the wind speed-up effect. See below for additional information about Kzt.

Kd =

Kd default = 0.85

Refer to Table 6-4, page 80

See below for additional information about the Kd factor.

 

Mean Roof Height = ft

Example 30'-6" is written as 30.5

 

Least Building width = ft

For determining Zone 5 dimension "a".

The following fields are optional and will show up on you printed page.

Project Name = optional

Company Name = optional

User Name = optional

E-mail = optional

 


A note about the Kzt factor: Kzt is a topographic effect factor to account for speed up over hills. Since I reside in Florida I use Kzt equals one and established that as the default value. Refer to your states Kzt values and adjust the value as required. I found a paper from the Florida International University stating few places in the state of Florida would warrant an escarpment factor greater than 1.0, therefore Kzt is unnecessary in the current endeavor. I found a great site showing the Kzt factors for Seattle, Washington from the Department of Planning and Development, their values range from 1.12 to 2. Refer to the links page for information.

A note about the Kd factor: Kd is a directionality factor. Over the years the Kd factor value has stirred up some controversy as to whether the value is 0.85 or should be one. I have set the default value to 0.85; if you are uncertain what value to use change the value to one for a worst case scenario. I found a good reference to this question at Engineering Express to support the Kd factor equals 0.85. Refer to the links page for information.

Please take a look at the MetalOpt.com material optimizer.
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