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Wind Load Report - Garage Conversion to ADU

1. Site & Building Data

Roof Type: Gable  
Wind Speed (ult): 110 mph
Exposure Category: C  
Enclosure Class: Enclosed  
Building Width (W): 20 ft.
Building Length (L): 24 ft.
Eave Height (he): 8 ft.
Foundation Height (hf): 0 ft.
Roof Pitch: 4 /12
Eave Overhang (OHe): 1.3 ft.
Gable Overhang (OHg): 1.3 ft.

2. Parameters & Coefficients

Topographic Factor (Kzt): 1.0
Directionality Factor (Kd): .85
Roof Angle (θ): 18.43 deg.
Mean Roof Height (h): 9.67 ft.
Ridge Height (hr): 11.33 ft.
Pos. Internal Pressure (+GCpi): +0.18  
Neg. Internal Pressure (-GCpi): -0.18  
Velocity Pressure Exp. Coeff. (Kh): 0.85 @ z=h
Velocity Pressure (qh): 22.35 psf
End Zone Width (a): 3.00 ft.
Zone 2/2E Dist.: 10.00 ft.

3. Design Assumptions and Notes

Code Standard: ASCE 7-10
Geometry: Regular-Shaped Bldg.
Height Class: Low-Rise Building
Notes:

4. Design Loads

Top Chord Dead Load: 7 psf
Bottom Chord Dead Load: 10 psf
Truss/Rafter Spacing: 24 in. o/c

4. Design Wind Pressures: MWFRS Envelope Procedure


Load Case A: Transverse Direction
Surface GCpf Design Pressure (psf)
(w/ +GCpi) (w/ -GCpi)
1 0.52 7.52 15.57
2 -0.69 -19.45 -11.40
3 -0.47 -14.49 -6.45
4 -0.42 -13.31 -5.26
1E 0.78 13.41 21.46
2E -1.07 -27.94 -19.89
3E -0.67 -19.07 -11.03
4E -0.62 -17.84 -9.79
2OH -0.69 -15.42
2EOH -1.07 -23.92
3OH -0.47 -10.47
3EOH -0.67 -15.05
2OH+W -0.69/-0.7 -31.07
2EOH+W -1.07/-0.7 -39.56
a) (+) and (-) signs signify wind pressures acting toward & away from surfaces.
b) External Pressure Coefficients linearly interpolated from Fig. 28.4-1 ASCE 7-10.
c) Design building for all wind directions, 4 load patterns per load case.
d) Total horizontal shear shall not be less than that by neglecting roof wind forces.
e) Min. wind load for enclosed or partially enclosed bldg.: 16 psf wall, 8 psf roof.
f) Design pressures are for strength design, multiply by 0.6 for ASD.
Wind Loads 1944 Delaware Ave West Sac. 40706
Engineer Name ENGINEERING COMPANY INC.
Street Address City, CA 99999
ph. (800) 000-0000    www.website.com
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Load Case B: Longitudinal Direction
Surface GCpf Design Pressure (psf)
(w/ +GCpi) (w/ -GCpi)
1 -0.45 -14.08 -6.03
2 -0.69 -19.45 -11.40
3 -0.37 -12.29 -4.25
4 -0.45 -14.08 -6.03
5 0.40 4.92 12.96
6 -0.29 -10.50 -2.46
1E -0.48 -14.75 -6.71
2E -1.07 -27.94 -19.89
3E -0.53 -15.87 -7.82
4E -0.48 -14.75 -6.71
5E 0.61 9.61 17.66
6E -0.43 -13.63 -5.59
2OH -0.69 -15.42
2EOH -1.07 -23.92
3OH -0.37 -8.27
3EOH -0.53 -11.85
2EOH+W -1.07/-0.7 -39.56
3EOH+W -0.53/-0.7 -27.49
a) (+) and (-) signs signify wind pressures acting toward & away from surfaces.
b) External Pressure Coefficients linearly interpolated from Fig. 28.4-1 ASCE 7-10.
c) Design building for all wind directions, 4 load patterns per load case.
d) Total horizontal shear shall not be less than that by neglecting roof wind forces.
e) Min. wind load for enclosed or partially enclosed bldg.: 16 psf wall, 8 psf roof.
f) Design pressures are for strength design, multiply by 0.6 for ASD.


Torsional Load Cases
Surface Load Case GCpf Design Pressure (psf)
(w/ +GCpi) (w/ -GCpi)
1T A - 1.88 3.89
2T A - -4.86 -2.85
3T A - -3.62 -1.61
4T A - -3.33 -1.32
5T B - 1.23 3.24
6T B - -2.63 -0.61
a) (+) and (-) signs signify wind pressures acting toward & away from surfaces.
b) Pressures designated with a "T" are 25% of full design wind pressures.
c) Torsional loading shall apply to all 8 load patterns using the figures shown.
d) Design pressures are for strength design, multiply by 0.6 for ASD.
e) Torsional Design Exceptions: One story bldg. with h ≤ 30 ft,
   Two stories or less framed with light frame construction,
   Two stories or less with flexible diaphragms.
Wind Loads 1944 Delaware Ave West Sac. 40706
Engineer Name ENGINEERING COMPANY INC.
Street Address City, CA 99999
ph. (800) 000-0000    www.website.com
-
7/6/2024 2
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5. Wind Load Calculations


1.) Lateral Loads - Transverse Direction:


Lateral Loads on Roof Diaphragm with Positive Internal Pressure
24 ft.
6.00 ft.
18.00 ft.
42.8 plf
31.9 plf
32.2 plf
18.0 plf
470 lbs
409 lbs
38.1 plf
29.0 plf
55.9 plf
38.9 plf
47.8 plf
30.8 plf
10.3 plf
8.1 plf
30.1 plf
20.9 plf
3.9 plf
2.7 plf
1.3 ft.
1.3 ft.
a) (-) signs signify wind lateral forces acting opposite to the direction of the arrows shown.
b) Strength design values multiplied by 0.6 to obtain ASD values.



Wind Base Shear (ASD)
Load Case A: Transverse Direction
Load Case Walls (lbs) Roof (lbs) Roof Overhangs (lbs) Total Lateral Load (lbs) R1 (lbs) R2 (lbs)
Positive Internal Pressure 1350 -285 -186 879 470 409
Negative Internal Pressure 1350 -285 -186 879 470 409
Roof Pressure = 0 1350 0 0 1350 731 619
Min. Pressures (8 psf, 16 psf) 922 384 97 1403 701 701
a) Bottom half of wall neglected in tributary area calculations.
b) Strength design values multiplied by 0.6 to obtain ASD values.
Wind Loads 1944 Delaware Ave West Sac. 40706
Engineer Name ENGINEERING COMPANY INC.
Street Address City, CA 99999
ph. (800) 000-0000    www.website.com
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7/6/2024 3
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2.) Lateral Loads - Longitudinal Direction:


Lateral Loads on Roof Diaphragm with Positive Internal Pressure
20 ft.
3.00 ft.
17.00 ft.
32.7 plf
25.2 plf
23.1 plf
11.8 plf
20.9 lbs
64.8 lbs
75.6 lbs
154.2 lbs
583 lbs
529 lbs
a) (-) signs signify wind lateral forces acting opposite to the direction of the arrows shown.
b) Strength design values multiplied by 0.6 to obtain ASD values.
c) Where the length of building (L) exceeds 4X the mean roof height (h), wind drag forces should additionally be considered.



Wind Base Shear (ASD)
Load Case B: Longitudinal Direction
Load Case Walls (lbs) Gable Ends (lbs) Roof (lbs) Total Lateral Load (lbs) RA (lbs) RB (lbs)
Positive Internal Pressure 797 315 0 1112 583 529
Negative Internal Pressure 797 315 0 1112 583 529
Roof Pressure = 0 797 315 0 1112 583 529
Min. Pressures (8 psf, 16 psf) 768 320 0 1088 544 544
a) Bottom half of wall neglected in tributary area calculations.
b) Strength design values multiplied by 0.6 to obtain ASD values.
Wind Loads 1944 Delaware Ave West Sac. 40706
Engineer Name ENGINEERING COMPANY INC.
Street Address City, CA 99999
ph. (800) 000-0000    www.website.com
-
7/6/2024 4
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3.) Roof Truss Reactions:


Roof Truss/Rafter Reactions: Transverse End Zone
152 lbs
58 lbs
Max. Horz. ① = 55 lbs
Max. Uplift ① = 152 lbs
a) Strength design values multiplied by 0.6 to obtain ASD values.
b) Windward loads may be positive or negative depending on pitch of roof.



Roof Truss/Rafter Reactions (ASD)
w/ Positive Internal Pressure
Load Case Horizontal Load (lbs) Gross Uplift (lbs) Net Uplift (lbs) U1 (lbs) U2 (lbs)
Transverse Int. Zone 31 472 32 48 -16
Transverse End Zone 48 649 209 152 58
Longitudinal Int. Zone 32 418 -22 16 -39
Longitudinal End Zone 55 581 141 117 24
a) Gross Uplift calculations do not include any counteracting roof dead loads.
b) Net Uplift calculations include counteracting roof dead loads multiplied by 0.6 per load case (7) ASCE 7-10.
c) Strength design values multiplied by 0.6 to obtain ASD values for wind loads.
d) Loads based on truss spacing calculated at 24" o/c.
e) Negative values for horizontal load indicate load acting in windward direction (tranverse load cases).
f) Negative values for uplift indicate net downward force (zero uplift).













*Disclaimer: The calculations produced herein are for initial design and estimating purposes only. The calculations and drawings presented do not constitute a fully engineered design. All of the potential load cases required to fully design an actual structure may not be provided by this calculator. For the design of an actual structure, a registered and licensed professional should be consulted as per IRC 2012 Sec. R802.10.2 and designed according to the minimum requirements of ASCE 7-10. The wind load calculations provided by this online tool are for educational and illustrative purposes only. Medeek Design assumes no liability or loss for any designs presented and does not guarantee fitness for use.
Wind Loads 1944 Delaware Ave West Sac. 40706
Engineer Name ENGINEERING COMPANY INC.
Street Address City, CA 99999
ph. (800) 000-0000    www.website.com
-
7/6/2024 5