PLASTIC LUMBER SPAN TABLE - JOIST MODE
UNIFORM LOAD LONG TERM CREEP (DEAD LOAD) L/360 TABLE
 
Modulus of Elasticity per ASTM - 3 minute test@ 72 Deg. F = 7030000 PSI
Modulus of Elasticity Creep Reduction Factor (10) year = 3
Temperature Adjustment Factor 90 DEG. F = 1.25
Creep and Temperature Adjusted Modulus of Elasticity = 187467 PSI
Deflection Limited to L/360 = 0.033 INCHES/FOOT
 
  

 

 
Nominal Size Rebar Actual Size       Board Only
Size Qty-Size Width Height I (In.ˆ4) Z (In.ˆ3) LBS  / FOOT
3 x 12 2 - 3/4" 2.4 11.3 288.6 51.1 10.2

L SPAN (FEET)
2 3 4 5 6 7 8 9 10 11 12

W - Allowable Uniform Load (LBS/FOOT)
9908 2929 1230 625 357 221 145 99 69 49 38
 
Notes:
 
1. Designers are to understand table limitations and apply them appropriately. Loads are assumed to be uniformly applied to a simple span condition.
2. Table Includes the weight of the beam in the allowable load values.
3. Table is based on adjusted modulus of elasticity based on long term creep and temprature.
4. All designs should be reviewed by a professional engineer.
5. Tables are generated from uniform loaded beam formula y = SWLˆ4/364EI
6. Example: In a pergola application can a 2 x 8 x 8' joist spaced 24" on center support the load of 2 x 4 boards placed on top of the 2 x 8 spaced 12" on center. The 2 x 4 boards weigh 2 lbs. / foot. The results in total loading on the 2 x 8 x 8' span is rated 7 lbs. / foot and load is 4 lbs. / foot. Application is OK for creep deflection of L/360.
 
STRUCTURAL PLASTIC LUMBER SPAN TABLE - JOIST MODE
UNIFORM LOAD LONG TERM CREEP (DEAD LOAD) L/240 TABLE
 
Modulus of Elasticity per ASTM D6108- 3 minute test@ 72 Deg. F = 306500 PSI
Modulus of Elasticity Creep Reduction Factor (10) year = 3
Temperature Adjustment Factor 72 DEG. F = 1
Creep and Temperature Adjusted Modulus of Elasticity = 102167 PSI
Deflection Limited to L/360 = 0.05 INCHES/FOOT

Nominal Size    Actual Size               Board Only

L SPAN (FEET)

W - Allowable Uniform Load (LBS/FOOT)
Size Width Height I (inˆ4) Z (inˆ3) LBS/ FOOt   2 3 4 5 6 7 8 9 10 11 12
5/4 x 4 1.1 3.5 3.9 2.2 1.4   110 32 12 6              
5/4 x 6 1.1 5.4 14.4 5.3 2.2   407 119 49 24 13            
5/4 x 8 1.1 7.3 35.7 9.8 3.0   1009 297 123 62 34 21 13        
2 x 2 1.5 1.5 0.4 0.6 0.8   11                    
2 x 3 1.5 2.5 2.0 1.6 1.4   54 15 6                
2 x 4 1.5 3.5 5.4 3.1 2.0   150 43 17 8              
2 x 6 1.5 5.4 19.7 7.3 3.0   556 162 67 33 18            
2 x 8 1.5 7.3 48.6 13.3 4.1   1376 405 168 84 47 28 17        
2 x 10 1.5 9.25 98.9 21.4 5.2   2802 827 346 174 99 60 39 26 17    
2 x 12 1.5 11.3 180.4 31.9 6.4   5112 1510 633 321 183 113 74 50 35 24 17
3 x 4 2.4 3.4 7.9 4.6 3.1   220 63 25 11              
3 x 6 2.4 5.5 33.3 12.1 5.0   939 275 113 55 30 17          
3 x 8 2.4 7.4 81.0 21.9 6.7   2293 675 281 141 79 47 29 19      
3 x 10 2.4 9.3 160.9 34.6 8.4   4557 1344 562 284 161 96 63 42 28    
3 x 12 2.4 11.3 288.6 51.1 10.2   8180 2416 1014 514 293 181 118 80 55 39 28
4 x 4 3.4 3.4 11.1 6.6 4.3   312 89 35 16              
4 x 6 3.4 5.4 44.6 16.5 6.9   1259 368 151 74 40 23          
4 x 8 3.4 7.5 119.5 31.9 9.6   3363 996 414 206 116 70 43 28      
4 x 10 3.4 9.375 233.5 49.8 12.0   6614 1951 816 412 233 143 92 61 41    
4 x 12 3.45 11.375 423.1 74.4 14.7   11994 3543 1456 754 430 265 173 117 81 57 41
5 x 5 4.4 3.85 20.9 10.9 6.4   587 170 66 32              
6 x 6 5.4 5.4 70.9 26.2 10.9   2000 585 240 118 64 36          
6 x 8 5.4 7.4 182.4 49.3 15.0   5160 1518 632 316 177 106 66 42      
6 x 12 5.4 11.3 649.3 114.9 22.9   18404 5437 2280 1156 560 407 265 179 125 88 62
8 x 8 7.3 7.3 236.7 64.8 20.0   6696 1970 820 410 229 137 85 54      
8 x 10 7.3 9.3 489.3 105.2 25.5   13861 4088 1710 863 489 296 192 127 86 56  
10 x 10 9.8 9.8 768.6 156.9 36.0   21178 6427 2691 1360 772 473 305 203 138 95 65
12 x 12 11.8 11.8 1615.6 273.3 52.2   45799 13533 5679 2882 1646 1017 664 451 315 223 160
Notes:
 
1. Designers are to understand table limitations and apply them appropriately. Loads are assumed to be uniformly applied to a simple span condition.
2. Table Includes the weight of the beam in the allowable load values.
3. Table is based on adjusted modulus of elasticity based on long term creep and temperature.
4. All designs should be reviewed by a professional engineer.
5. Tables are generated from uniform loaded beam formula y = 5WLˆ4/364EI
6. Example: In a pergola application can a 2 x 8 x 8' joist spaced 24" on center support the load of 2 x 4 boards placed on top of the 2 x 8 spaced 12" on center. The 2 x 4 boards weigh 2 lbs. / foot. The results in total loading on the 2 x 8  of 4 lbs. / foot span is rated 7 lbs. / foot and load is 4 lbs. / foot. Application is OK for creep deflection of L/240
 
STRUCTURAL PLASTIC LUMBER SPAN TABLE - JOIST MODE
UNIFORM LOAD LONG TERM CREEP (DEAD LOAD) L/360 TABLE
 
Modulus of Elasticity per ASTM - 3 minute test@ 72 Deg. F = 306500 PSI
Modulus of Elasticity Creep Reduction Factor (10) year = 3
Temperature Adjustment Factor 90 DEG. F = 1.25
Creep and Temperature Adjusted Modulus of Elasticity = 81733 PSI
Deflection Limited to L/360 = 0.033 INCHES/FOOT
 

Nominal Size    Actual Size               Board Only

L SPAN (FEET)

W - Allowable Uniform Load (LBS/FOOT)
Size Width Height I (inˆ4) Z (inˆ3) LBS/ FOOt   2 3 4 5 6 7 8 9 10 11 12
                                   
5/4 x 4 1.1 3.5 3.9 2.2 1.4   57 16 6 2              
5/4 x 6 1.1 5.4 14.4 5.3 2.2   214 62 25 12 6            
5/4 x 8 1.1 7.3 35.7 9.8 3.0   531 155 64 31 17 9 5        
2 x 2 1.5 1.5 0.4 0.6 0.8   5                    
2 x 3 1.5 2.5 2.0 1.6 1.4   28 7 2                
2 x 4 1.5 3.5 5.4 3.1 2.0   78 22 8 3              
2 x 6 1.5 5.4 19.7 7.3 3.0   292 84 34 16 8            
2 x 8 1.5 7.3 48.6 13.3 4.1   725 212 87 43 23 13 7        
2 x 10 1.5 9.25 98.9 21.4 5.2   1477 434 180 90 50 29 18 11 7    
2 x 12 1.5 11.3 180.4 31.9 6.4   2696 794 331 167 94 57 36 23 15 10 6
3 x 4 2.4 3.4 7.9 4.6 3.1   115 32 12 4              
3 x 6 2.4 5.5 33.3 12.1 5.0   494 143 57 27 14 7          
3 x 8 2.4 7.4 81.0 21.9 6.7   1208 353 145 71 38 22 12 7      
3 x 10 2.4 9.3 160.9 34.6 8.4   2402 706 293 146 81 48 29 18 11    
3 x 12 2.4 11.3 288.6 51.1 10.2   4314 1271 530 267 150 91 57 37 24 16 10
4 x 4 3.4 3.4 11.1 6.6 4.3   163 45 17 6              
4 x 6 3.4 5.4 44.6 16.5 6.9   662 191 77 36 18 9          
4 x 8 3.4 7.5 119.5 31.9 9.6   1782 521 214 105 57 32 18 10      
4 x 10 3.4 9.375 233.5 49.8 12.0   3486 1025 425 212 118 70 43 26 16    
4 x 12 3.45 11.375 423.1 74.4 14.7   6326 1864 787 391 220 133 84 55 36 23 15
5 x 5 4.4 3.85 20.9 10.9 6.4   307 87 33 14              
6 x 6 5.4 5.4 70.9 26.2 10.9   1051 304 122 57 28 14          
6 x 8 5.4 7.4 182.4 49.3 15.0   2717 795 327 160 86 49 28 15      
6 x 12 5.4 11.3 649.3 114.9 22.9   9707 2860 1193 600 337 204 129 84 55 36 22
8 x 8 7.3 7.3 236.7 64.8 20.0   3526 1031 423 207 111 63 35 19      
8 x 10 7.3 9.3 489.3 105.2 25.5   7307 2147 891 444 246 146 89 55 33 19  
10 x 10 9.8 9.8 768.6 156.9 36.0   11482 3377 1404 701 391 233 144 90 56 33 17
12 x 12 11.8 11.8 1615.6 273.3 52.2   24157 7121 2974 1497 844 512 326 213 144 93 60
Notes:
 
1. Designers are to understand table limitations and apply them appropriately. Loads are assumed to be uniformly applied to a simple span condition.
2. Table Includes the weight of the beam in the allowable load values.
3. Table is based on adjusted modulus of elasticity based on long term creep and temperature.
4. All designs should be reviewed by a professional engineer.
5. Tables are generated from uniform loaded beam formula y = 5WLˆ4/384EI
6. Example: In a pergola application can a 2 x 8 x 8' joist spaced 24" on center support the load of 2 x 4 boards placed on top of the 2 x 8 spaced 12" on center. The 2 x 4 boards weigh 2 lbs. / foot. The results in total loading on the 2 x 8  of 4 lbs. / foot span is rated 7 lbs. / foot and load is 4 lbs. / foot.  Using the chart a 2 x 8 at 8' span is rated at 7 lbs /foot and load is 4 lbs /foot.
Application is OK for creep deflection of L/360