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Wind Load Report - Patio Addition

1. Site & Building Data

Roof Type: Gable  
Wind Speed (ult): 110 mph
Exposure Category: C  
Enclosure Class: Partially Enclosed  
Building Width (W): 28 ft.
Building Length (L): 31.5 ft.
Eave Height (he): 8 ft.
Foundation Height (hf): 0 ft.
Roof Pitch: 5 /12
Eave Overhang (OHe): 0 ft.
Gable Overhang (OHg): 0 ft.

2. Parameters & Coefficients

Topographic Factor (Kzt): 1.0
Directionality Factor (Kd): .85
Roof Angle (θ): 22.62 deg.
Mean Roof Height (h): 10.92 ft.
Ridge Height (hr): 13.83 ft.
Pos. Internal Pressure (+GCpi): +0.55  
Neg. Internal Pressure (-GCpi): -0.55  
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.: 14.00 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 0.54 -0.27 24.31
2 -0.45 -22.44 2.14
3 -0.47 -22.73 1.86
4 -0.41 -21.55 3.03
1E 0.77 4.94 29.53
2E -0.72 -28.36 -3.78
3E -0.65 -26.78 -2.19
4E -0.60 -25.66 -1.07
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 7608 Live Oak 40411
N. Wilkerson MEDEEK ENGINEERING INC.
3050 State Route 109 Copalis Beach, WA 98535
ph. (425) 420-5715    www.medeek.com 		-
5/22/2024 1
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Load Case B: Longitudinal Direction
Surface GCpf Design Pressure (psf)
(w/ +GCpi) (w/ -GCpi)
1 -0.45 -22.35 2.24
2 -0.69 -27.71 -3.13
3 -0.37 -20.56 4.02
4 -0.45 -22.35 2.24
5 0.40 -3.35 21.23
6 -0.29 -18.77 5.81
1E -0.48 -23.02 1.56
2E -1.07 -36.21 -11.62
3E -0.53 -24.14 0.45
4E -0.48 -23.02 1.56
5E 0.61 1.34 25.93
6E -0.43 -21.90 2.68
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 - -0.07 6.08
2T A - -5.61 0.54
3T A - -5.68 0.46
4T A - -5.39 0.76
5T B - -0.84 5.31
6T B - -4.69 1.45
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 7608 Live Oak 40411
N. Wilkerson MEDEEK ENGINEERING INC.
3050 State Route 109 Copalis Beach, WA 98535
ph. (425) 420-5715    www.medeek.com 		-
5/22/2024 2
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5. Wind Load Calculations


1.) Lateral Loads - Transverse Direction:


Lateral Loads on Roof Diaphragm with Positive Internal Pressure
31.5 ft.
6.00 ft.
25.50 ft.
61.6 plf
51.7 plf
11.9 plf
-0.7 plf
906 lbs
829 lbs
93.7 plf
79.5 plf
99.3 plf
78.6 plf
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 1743 -8 0 1735 906 829
Negative Internal Pressure 1743 -8 0 1735 906 829
Roof Pressure = 0 1743 0 0 1743 926 817
Min. Pressures (8 psf, 16 psf) 1210 882 0 2092 1046 1046
a) Bottom half of wall neglected in tributary area calculations.
b) Strength design values multiplied by 0.6 to obtain ASD values.
Wind Loads 7608 Live Oak 40411
N. Wilkerson MEDEEK ENGINEERING INC.
3050 State Route 109 Copalis Beach, WA 98535
ph. (425) 420-5715    www.medeek.com 		-
5/22/2024 3
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2.) Lateral Loads - Longitudinal Direction:


Lateral Loads on Roof Diaphragm with Positive Internal Pressure
28 ft.
3.00 ft.
25.00 ft.
52.6 plf
45.1 plf
3.2 plf
-8.0 plf
26.2 lbs
127.2 lbs
233.3 lbs
377.8 lbs
957 lbs
900 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 1093 764 0 1857 957 900
Negative Internal Pressure 1093 764 0 1857 957 900
Roof Pressure = 0 1093 764 0 1857 957 900
Min. Pressures (8 psf, 16 psf) 1075 784 0 1859 930 930
a) Bottom half of wall neglected in tributary area calculations.
b) Strength design values multiplied by 0.6 to obtain ASD values.
Wind Loads 7608 Live Oak 40411
N. Wilkerson MEDEEK ENGINEERING INC.
3050 State Route 109 Copalis Beach, WA 98535
ph. (425) 420-5715    www.medeek.com 		-
5/22/2024 4
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3.) Roof Truss Reactions:


Roof Truss/Rafter Reactions: Transverse End Zone
174 lbs
161 lbs
Max. Horz. ① = 84 lbs
Max. Uplift ① = 262 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 -2 759 168 83 85
Transverse End Zone 11 926 336 174 161
Longitudinal Int. Zone 50 811 220 140 80
Longitudinal End Zone 84 1014 423 262 161
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 7608 Live Oak 40411
N. Wilkerson MEDEEK ENGINEERING INC.
3050 State Route 109 Copalis Beach, WA 98535
ph. (425) 420-5715    www.medeek.com 		-
5/22/2024 5