helps you with your entries. This information is provided on each program for quick and

easy reference, but can also be found in the ASCE 7 book; in Chapter 6).

1. Wind Velocity: The number entered in this cell is to have the units

    in miles per hour (mph). This is the velocity zone

    location that your building is located, according to

    the ASCE 7 Basic Wind Speed Map. The map is

    provided with the purchase of your programs.

2. Building Category: Make your selection from the pull-down list. The

    options are provided in the description given on the

    program (place cursor over the top of the

    description.) If you need more information on

    Building Categories, please reference Table 1-1 in

    the ASCE 7 book.

3. Importance Factor: The value is automatically calculated for you, based

    on your “Building Category” entry. You can view

    the values of the Importance Factor from the

    “Building Category” description; when placing your

    cursor over the top of the description.

4. Exposure: From the pull-down list you have three (3) choices.

    Exposures B, C, & D. (Exposure A was eliminated

    after ASCE 7-98). Make your selections based on

    the information that is provided is the description.

    (The description provided is the same description

    you will find in ASCE 7).

5. Internal Pressure: Make your selection from the pull-down list

    provided. You have three (3) choices. 1) Partially

    Enclosed, 2) Enclosed Building, 3) Open Building.

     a. Partially Enclosed: This type of building has

         walls under the roof, but also has at least one

         side that is exposed or open to the outside.

     b. Enclosed: This is the most common. This type

         of building has no openings exposed to the

         outside. The walls enclose the entire building

         under the roof.

     c. Open Building: This type of structure has no

         walls under the roof, and is completely exposed

         to the outside. This would basically be a roof

         that is only supported by post, pillars or similar

         supports.

6. Height Above Ground: This is also know as the value “z”. This value is for

    elevated buildings, for the simple fact that the value

    of “z” is the dimension from the ground to the

    bottom of your building. So if your building is at

    ground level, this value would be zero (0).

7. Standard Wall Height: This value is the dimension measured from the

    ground to the eave height (or where the lower

    portion of your roof meets the side-wall) of your

    building.

8. Mean Roof Height: This also known as the value “h”. This value is the

    dimension measured from grade to the average of

    the roof eave height and the highest point on the

    roof surface, except that eave height shall be used

    for the roof angle if it is less than or equal to 10

    degrees.

    Remember: When h > 60 ft., your roof angle must

    be less than or equal to 10 degrees; according to the

    ASCE 7.

    Flat Roofs: This will be the actual building height

    value.

9. Building Width: This value is the width dimension of your building;

    in feet.

10. Building Length: This value is the length dimension of your building;

      in feet.

11. Roof Slope: This is the value of “x” over twelve; or x/12. You

      need to enter a value from 0-12 (Zero (0) is flat, and

      twelve (12) is 45 degrees).

12. Roof Angle: This value is automatically calculated and entered

      for you. It displays the angle of your roof based on

      the value of “x” entered for your roof’s slope.

13. Edge Strip: This value is also known as the value of “a”. This

      value is automatically calculated based off of the

      building information you entered. The Edge Strip

      value (“a”), is used to determine the dimensions of

      zone five (5) for your wall sections, and zone (3) for

      your roof sections.

14. End Zone: This value is the total Edge Strip value along one

      side of your wall. This value is also automatically

      calculated for you, based off of the building

      information you entered in. It is basically the value

      of “a” multiplied by two (2).

All the “Building Information” is entered, next is to find the wind loads for the roof,

door(s), and window(s).

Below is a diagram that shows the garage that we are finding wind loads for. As you can

see the numbers below show the zones for the garage.

Note:

1. Zones 1, 2, & 3 are always applied to the roof.

     a. Zone 3: are the edge or corner sections; always equal to the value of “a”.

     b. Zone 2: are the perimeter sections; minus the Zone 3 (edge/corner) areas.

     c. Zone 1: are the interior sections. Basically the interior area left over after

         subtracting the areas of the Zone 3, and Zone 2.

2. Zones 4 & 5 are always applied to the walls.

     a. Zone 5: are the corner sections; always equal to the value of “a”.

     b. Zone 4: are the interior sections; or the area remaining after subtracting the

         Zone 5 sections.

3. Remember: The Value of “a” is always applied to the roof and wall corners.

4. Remember: Any door or window dimension that falls within the area of “a”

    (edge/corner = Zone 5) section must have the Zone 5 applied to it.

5. Remember: Any opening dimension that falls with the area of “a” (edge/corner =

    Zone 3) on the roof (such as a sky-light) must have the Zone 3 applied to it.

Finding Roof Wind Loads: