Technical Specifications

P. 32
Allowable Roof Uniform Load Capacities (continued)
TABLE 18 B
–
LDF = 1.15
P3 Joist — PJI 90 with Web Stiffeners
Allowable uniform loads (PLF) Roof
Clear
Joist
Span
(ft�)
18” 20” 22” 24”
Live
Load
Total
Load
Live
Load
Total
Load
Live
Load
Total
Load
Live
Load
Total
Load
Defl�
L/240
Snow
115%
Non-
Snow
125%
Defl�
L/240
Snow
115%
Non-
Snow
125%
Defl�
L/240
Snow
115%
Non-
Snow
125%
Defl�
L/240
Snow
115%
Non-
Snow
125%
20 182 198 182 198 182 198 182 198
21 173 188 173 188 173 188 173 188
22 165 180 165 180 165 180 165 180
23 158 172 158 172 158 172 158 172
24 151 165 151 165 151 165 151 165
25 145 158 145 158 145 158 145 158
26 140 152 140 152 140 152 140 152
27 135 146 135 146 135 146 135 146
28 130 141 130 141 130 141 130 141
29 125 136 125 136 125 136 125 136
30 121 132 121 132 121 132 121 132
31 117 127 117 127 117 127 117 127
32 111 114 123 114 123 114 123 114 123
33 101 110 120 110 120 110 120 110 120
34 93 107 116 107 116 107 116 107 116
35 85 101 113 104 113 104 113 104 113
36 78 95 104 99 101 110 101 110 101 110
37 72 90 96 91 98 107 98 107 98 107
38 66 86 89 84 95 103 96 104 69 104
39 61 81 82 78 90 98 93 101 93 101
40 57 76 76 72 86 93 89 91 99 91 99
41 53 71 71 67 81 89 83 89 96 89 96
42 49 66 66 62 78 83 77 85 92 87 94
43 46 61 61 58 74 77 72 81 88 85 92
44 43 57 57 54 71 72 67 77 84 81 83 90
45 40 53 53 51 67 67 62 74 81 76 80 87
46 37 50 50 47 63 63 58 71 77 71 77 84
47 35 47 47 44 59 59 55 68 73 66 74 80
48 33 44 44 42 56 56 51 65 69 62 71 77
49 31 41 41 39 52 52 48 62 64 59 68 74
50 29 39 39 37 49 49 46 60 61 55 65 71
NOTES
1� Roof joists or rafters must be sloped
a minimum of 1/4” in 12”�
2� Live Load column limits deflection
to L/240� Total Load column limits def-
lection to L/180
3� Values represent the most restric-
tive of simple span or multiple span
conditions�
4� Values are for P3 Joist spaced a
maximum of 24” on center�
5� Table assumes a minimum end bearing
length of 1-3/4” and a minimum interior
bearing length of 3-1/2”�
6� Web stiffeners are required at each
support.
7� Tabulated values are clear span as
measured between the face of the
supports�
JOIST SIZING
1� Select desired span (row)�
2� Select Joist depth (column) to satisfy
both Live Load and Dead Load capacity�
3� If Live Load column is blank, Total Load
capacity controls�