Wind
V from Figure 26.5-1 for your risk category (ASCE 7 Hazard Tool). Kzt = 1.0 away from hills and escarpments (§26.8). Ke from Table 26.9-1; 1.0 is always permitted.
Building
The engine picks the figure from these: Part 1 (h ≤ 60 ft) uses Figure 30.3-1 for walls and the roof figure for your shape and slope. Automated today: walls, and flat or gable roofs with θ ≤ 7° (Figure 30.3-2A). Other roofs and taller buildings are named, not guessed.
Components
A is the effective wind area of §26.2 for the stud, fastener, panel or window you are checking: the span times an effective width that need not be less than one third of the span. GCp is read off the figure at that area, between its breakpoints on a log scale.
Results
Which figure, and why
Velocity pressure ASCE 7-22 §26.10
Zones
Design pressures p = qh·Kd·[(GCp) − (GCpi)]
Positive acts toward the surface, negative away from it (suction). Each component is designed for both its maximum positive and maximum negative pressure (Figure 30.3-1 Note 4).
All four envelope cases per zone
Engine trace
Formula chain, as the engine reports it
Run a calculation to see the chain.
How it works
- The height and the enclosure pick the part of Chapter 30; the roof shape and slope pick the roof figure. The page says which, and why, above the numbers.
- Kh = 2.41(h/zg)2/α (Table 26.10-1 note 1, constants from Table 26.11-1); qh = 0.00256·Kh·Kzt·Ke·V² (Eq. 26.10-1). The eave height is used when θ ≤ 10°.
- The zone width a and the roof zones come from the figure notes and diagrams; GCp is read off the figure at your effective wind area, with the notes applied (walls reduced 10% when θ ≤ 10°; the parapet rule of Figure 30.3-2A note 5).
- GCpi from Table 26.13-1, Kd = 0.85 from Table 26.6-1, and each zone's four envelope cases p = qh·Kd·[(GCp) − (GCpi)] (Eq. 30.3-1).
The same compiled engine runs in the StructuralClaw desktop app.