Wind Load Calculator for Signs, Fences and Solar Mounts

Velocity pressure is $q_0 = 0.613 V_{ref}^2$, with 0.613 kg/m³ equal to half the assumed air density. The pressure exposure profile is $K(z)=K_{ref}[\max(z,z_{min})/z_{ref}]^{2\alpha}$. Other pressure factors are multiplied once. Sign and solar pressure is uniform at the top edge; fences use 101-point trapezoidal integration of this power-law profile, including its constant lower segment. The fence resultant height is the pressure-weighted first moment divided by pressure area.

Net force is $F_N=qGC_fA_{ref}$. Tabler (2003), printed pp. 187–189 (attached pp. 225–227), defines porous area by the outline, including holes, and provides $C_f=1.4(1-P^2)$ for coarse, long fences with $P>0.3$. Its coefficients use mean squared velocity over the face, which is why fences use profile integration. The solid-fence example is 1.22. The sign example 1.76 comes from the 2020 Paine Field B-01 calculation, using 2015 IBC. Suárez et al. (2022), Section 3.3, reports an approximate mean normal coefficient magnitude 3.0 at +35° for its particular single-panel configuration. These examples require replacement where their geometry, flow or averaging conventions do not apply.

For solar tilt $\beta$, $H=F_N\sin\beta$, $Z=\pm F_N\cos\beta$. Gross panel area is used, with no extra projected-area multiplier. A conservative base-moment envelope is $M=H z_{cp}+|Z|e$; contributions are added without credit for cancellation. Loads and moment divide equally among the specified posts.

The lateral soil screen rearranges the nonconstrained embedded-post equation published in ICC's January 2008 public errata, printed p. 77 (PDF p. 79): $d=0.5A[1+\sqrt{1+4.36h/A}]$, $A=2.34H/(S_1D)$. With bearing gradient $k=p_{soil}/z_{soil}$ and $S_1=k d/3$ and $h=M/H$, its division-free form is $U=2.34(Hd+1.09M)/(S_1Dd^2)$. Loads in this expression are multiplied by the chosen allowable-basis wind multiplier. $D_{req}=UD$ is the model diameter at the supplied depth. The algebra and power-law integration are derived here; no standard tables are reproduced.

The Paine Field B-01 example reports an 8.957 ft moment arm even though its 13 ft top and 5.67 ft face imply a geometric-center height of 10.165 ft. Its pressure and force are used as references; its inconsistent moment is not reproduced. The footing screen is checked separately against Andrew (2012), pp.3–5, using his explicit 200 psf/ft gradient.

Rigid, rectangular, isolated faces and one wind cross-section. Wind coefficients are magnitudes of net force normal to the face; tangential drag is omitted. Fence examples are long, ground-contact barriers; a custom coefficient is needed for elevated fences or other fabrics. Air density is fixed at 1.226 kg/m³. The illustrative exponent 0.14 and 5 m profile floor are user assumptions, not named code exposures.

The sign default is a 2 m × 1.2 m face with 1 m clearance, 40 m/s reference wind and two posts. Coefficients, gust factor and pressure factors must share compatible speed, area and averaging conventions. A peak coefficient or peak pressure may require G = 1 to avoid counting gust effects twice.

The solar example is a mean-force research value, not a validated peak-load design coefficient. Changing tilt does not update it. Equal post sharing ignores stiffness differences and torsion. The envelope includes vertical-force eccentricity but excludes separate aerodynamic pitching moments. No credit is taken for dead weight against uplift. The entered allowable pressure at a known depth defines a linear lateral bearing gradient (default 30 kPa at 1 m); soil pressure grows linearly with depth; the post and footing behave rigidly, with no lateral restraint at ground level and competent soil surrounding the embedded portion.

Preliminary estimates only. This calculator is not a complete implementation of ASCE/SEI 7-22 or EN 1991-1-4:2005+A1:2010. Source examples use older rules (including 2015 IBC / ASCE 7 and FEMA's ASCE 7-05 example); they validate arithmetic, not current local compliance. Engineering basis reviewed 28 October 2026. Check against the standard in force and its national or local amendments.

The Tabler porous relation is restricted to open fraction greater than 0.30 and at most 0.95 here, for coarse, long fences; small mesh, screens, blockage by snow or foliage, and end effects need another coefficient. The solar example coefficient only represents its reported configuration and flow; replace it for a project. Reassess pressure factors if the power law is extrapolated above the reference height.

The footing screen is restricted to 0.1–3.6 m embedment and checks lateral bearing only. It does not verify uplift, vertical bearing, frost, scour, groundwater effects, settlement, deflection, post strength, reinforcement or connections. A utilization below one is not a foundation approval. Installation work belongs to a qualified person.