1-28
Wind Design
Page 8
FM Global Property L o s s Prevention Data Sheets
Table 3. Roof Field Area (Zone 1) Uplift Design Pressure, p, for Exposure B, Flat or Gable Roof, Q s 7°
(For 60 ft (18 m) < h < 90 ft (27 m), limited to h/w < 1); Enclosed
Building
p = 0.00256 K Kz, KrfV
2
I [(GC,J - (GC )]
2
pl
in pounds per ft
(psf)
2
Enclosed Building; Roof Zone 1 (Field Area), Effective Wind Area 1 to 10 ft ;
= 1.0; z = h; (GCJ = - 1.0 for h < 90 ft and (GC ) = - 1.4 for h 2 90 ft; (GC„J = 0.18
2
K
a
B
Basic Wind Speed, V, 3-sec gust,
Mean
Roof
Height
h(ft)
< 85
0-15
15
17
21
25
30
35
41
43
30
15
17
21
25
30
35
41
43
60
18
20
25
31
36
43
49
89
20
23
28
34
41
48
90
27
31
38
46
55
90
100
110
130
120
140
(mph)
145
160
170
185
47
53
60
71
47
53
60
71
53
57
65
73
86
55
60
64
72
82
97
64
74
80
86
97
110
130
134
Roof Field Area Uplift Design Pressure,
750
p, Exposure
B (psf)
100
28
32
39
47
56
66
77
82
88
100
113
200
34
39
48
58
80
93
100
107
163
39
43
53
65
91
105
112
121
122
137
138
300
69
77
155
183
400
42
47
58
70
84
98
114
122
131
149
168
199
500
45
50
62
75
89
105
121
130
139
158
179
212
V I [(GCJ
- (GCJ]
80
85
3.6
p = 0.000613
K, K
it
K
d
2
in kilopascals
(kPa)
Enclosed Building; Roof Zone 1 (Field Area), Effective Wind Area 0.1 to 0.9 m ;
= 1.0; z = h; (GCp) = - 1.0 for h< 27 m and (GCJ = - 1.4 for h>27 m; (GCJ = 0.18
2
K
a
Mean
Basic Wind Speed, V, 3-sec gust,
(m/s)
Roof
Height
h(m)
0-5
< 38
40
45
0.7
08
1.0
1.2
1.5
1.8
2.1
2.4
2.8
3.2
10
0.7
0.8
1.0
1.3
1.5
1.8
2.2
2.5
2.9
3.3
3.7
18
0.9
1.0
1,2
1.5
1.8
2.2
2.5
2.9
3.4
3.8
4.3
50
55
60
Roof Field Area Uplift Design Pressure,
65
70
p, Exposure
75
B (kPa)
20
0.9
1.0
1.3
1.6
1.9
2.2
2.6
3.0
3.5
4.0
4.5
27
1.0
1.1
1.4
1.7
2.0
2.4
2.9
3.3
1.3
1.5
1.8
2.3
2.7
3.3
3.8
4.4
4.3
5.8
4.9
27.4
3.8
5.1
30
1.3
1.5
1.9
2.3
2.8
3.4
3.9
4.6
5.2
6.0
6.7
65
60
1.6
1.8
2.3
2.8
3.4
4.1
4.8
5.6
6.4
7.3
8.2
90
1.8
2.0
2.6
3.2
3.9
4.6
5.4
6.3
7.2
8.2
9.2
120
2.0
2.2
2.8
3.5
4.2
5.0
5.9
6.8
7.8
8.9
10.0
150
2.1
2.4
3.0
3.7
4.5
5.3
6.2
7.2
8.3
9.4
10.7
Notes:
1. Interpolation is appropriate.
2. Pressure (p), is total net pressure (external and internal).
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