Lecture 11 – ASCE 7-22
CES 5585: Wind Engineering
Pedro L. Fernández-Cabán, Ph.D.
FAMU-FSU College of Engineering
Fall 2025
Process for Determining Wind Loads (ASCE/SEI 7-22)
Continue!
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Chapter 27 - Directional Procedure
Chapter 27 - Commentary
“The Directional Procedure of Chapter 27 applies to “regular-shaped buildings,” as
defined in Chapter 26 and its commentary. For low-rise buildings with non-rectangular
plan shapes, such as L, T, and U, with single- or multilevel roofs, and/or multiridge/hip/gable roof systems, it is reasonable for the designer to use Chapter 27
provisions and pressure coefficients, in conjunction with engineering judgment, unless
the Wind Tunnel Procedure of Chapter 31 is utilized. When utilizing engineering judgment
to apply the ASCE 7 external pressure coefficients to a low-rise nonrectangular building,
the designer should consider the advice of an engineer knowledgeable of wind
pressure distribution for the location and application of the external pressure
coefficients, as well as the guidance available in literature recognized by the applicable
building code.”
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Chapter 27 - Directional Procedure
Chapter 27 - Commentary
“Most building codes adopted in the United States specifically recognize high-wind
design standards, guides, and manuals that include guidance for low-rise buildings with
nonrectangular plan shapes, specifically, utilizing the so-called Inscribed Structure
Method and Separate Structures Method.”
• ICC 600-2014 Standard for Residential Construction in High-Wind Regions
• AISI S230-19 Standard for Cold-Formed Steel Framing
• Wood Frame Construction Manual
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Chapter 27 - Directional Procedure
Example 6.4: For the building shown below, sketch the wind pressure distribution for all building
surfaces using guidance from the directional procedure of ASCE/SEI 7-22.
Monoslope
1:5.3
Wind
15 ft
30 ft
50 ft
20 ft
ELEVATION
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Chapter 27 - Directional Procedure
Example 6.4: For the building shown below, sketch the wind pressure distribution for all building
surfaces using guidance from the directional procedure of ASCE/SEI 7-22.
Streamlines
Wind
ELEVATION
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Chapter 27 - Directional Procedure
Example 6.4: For the building shown below, sketch the wind pressure distribution for all building
surfaces using guidance from the directional procedure of ASCE/SEI 7-22.
Wind Pressure
Distribution
Wind
ELEVATION
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Chapter 27 - Directional Procedure
https://domeroof.com/
Domed Roofs
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Chapter 27 - Directional Procedure
Example 6.5: Compute the external pressure coefficient (at A, B and C) of a dome with a circular
base using the directional procedure of ASCE/SEI 7-22.
B
x
Wind
A
x
xB
Height to base of dome = 20 ft
B
Dome Rise = 10 ft
xC
x
Plan View
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Chapter 27 - Directional Procedure
Arched Roofs
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Chapter 27 - Directional Procedure
Arched Roofs
https://www.achrnews.com/articles/148033-applications-in-the-field-curved-roof-tops-florida-beachfront-home
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Chapter 27 - Directional Procedure
Example 6.6: Compute the external pressure coefficient of a dome with a circular base using the
directional procedure of ASCE/SEI 7-22.
Arched Roof
5 ft
Wind
10 ft
25 ft
ELEVATION
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Chapter 27 - Directional Procedure
Example 6.6: Compute the external pressure coefficient of a dome with a circular base using the
directional procedure of ASCE/SEI 7-22.
Wind Pressure
Distribution
(Roof)
Wind
ELEVATION
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Chapter 27 - Directional Procedure
Open Buildings
Open Buildings with Monoslope,
Pitched, or Troughed Free Roofs
(ASCE 7-22, 27.3-2)
Net pressure coefficient determined from:
https://www.the-sun.com/money/6668646/target-update-curbside-pickup/
•
•
•
•
Figure 27.3-4 – Monoslope roof
Figure 27.3-5 – Pitched roof
Figure 27.3-6 – Troughed Roof
Figure 27.3-7 – Along-ridge/valley wind load case
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Chapter 27 - Directional Procedure
Open Buildings – Monoslope
https://www.kbuildings.com/types-of-k-buildings/
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Chapter 27 - Directional Procedure
Open Buildings – Monoslope
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Chapter 27 - Directional Procedure
Open Buildings – Monoslope
Notes
1. CNW and CNL denote net pressures (contributions from top and bottom surfaces) for
windward and leeward half of roof surfaces, respectively.
2. Clear wind flow denotes relatively unobstructed wind flow with blockage less than or equal to
50%. Obstructed wind flow denotes objects below roof inhibiting wind flow (> 50% blockage).
3. For values of θ between 7.5 and 45 degrees, linear interpolation is permitted.
4. For free roofs with 0.05 ≤ h/L < 0.25 and θ < 5 degrees, use Figure 27.3-7.
5. Plus and minus signs signify pressures acting toward and away from the top roof surface,
respectively.
6. All load cases shown for each roof angle shall be investigated.
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Chapter 27 - Directional Procedure
Open Buildings – Pitched (Free) Roofs
ASCE/SEI 7-22
https://storables.com/articles/what-is-the-roof-of-a-porch-called/
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Chapter 27 - Directional Procedure
Open Buildings – Pitched (Free) Roofs
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Chapter 27 - Directional Procedure
Open Buildings – Troughed Free Roofs
ASCE/SEI 7-22
https://www.dlubal.com/en-US/support-and-learning/support/knowledge-base/001542
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Chapter 27 - Directional Procedure
Open Buildings – Troughed Free Roofs
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Chapter 27 - Directional Procedure
Wind Along-Ridge/Valley
(Open Buildings)
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