Technical Specifications

P. 27
Allowable Roof Uniform Load Capacities
TABLE 15
–
LDF = 1.15
P3 Joist — PJI 40
Allowable uniform loads (PLF) Roof
Clear
Joist
Span
(ft�)
9-1/2” 11-7/8” 14” 16”
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%
6 323 351 374 407 374 407 374 407
7 278 302 322 336 322 336 322 336
8 244 265 282 295 282 295 282 295
9 217 236 251 262 251 262 251 262
10 196 213 227 237 227 237 227 237
11 178 194 206 215 206 215 206 215
12 153 166 189 198 189 198 189 198
13 130 142 174 183 175 183 175 183
14 113 122 150 163 163 170 163 170
15 98 107 131 143 152 158 152 158
16 86 94 115 125 142 149 142 149
17 77 83 102 111 134 140 134 140
18 68 74 91 99 120 130 127 132
19 61 61 67 82 89 108 117 118 125
20 52 56 60 74 81 97 106 107 116
21 45 50 55 67 73 88 96 97 105
22 39 46 50 61 67 81 88 88 96
23 34 42 46 56 61 74 80 81 88
24 30 39 41 52 56 68 74 74 81
25 27 36 36 46 48 52 62 68 69 75
26 32 32 41 44 48 58 63 63 69
27 29 29 37 41 44 53 54 58 59 64
28 26 26 33 38 41 48 50 54 55 60
29 30 35 39 43 47 51 51 56
30 27 33 36 39 43 47 48 52
31 31 32 35 41 44 45 49
32 29 29 32 38 42 42 46
33 27 27 29 36 39 39 43
34 27 34 36 37 37 40
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-
lec tion to L/180� Cathedral ceilings or
sheet rocked rafters may require stiffer
performance or additional design�
3� Values represent the most restric-
tive of simple span or multiple span
conditions�
4� Values are for P3 Joist spaced at 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 not required
except when the joist hangers do not
pro videlateral support for the top flange
of the P3 Joist� Web stiffeners are
required at birdsmouth cuts and when
required by hanger manufacturers for
properconnections�
JOIST SIZING
1� Select desired joist depth (column)�
2� Select desired span (row)�
3� Check BOTH Live Load and Total Load
columns�
4� If Live Load column is blank, Total Load
capacity governs�