PDFWAC 51-11C-610221

Tables A102.2.4—Steel truss framed ceiling Uo values.

Table A102.2.4(1)
Steel Trussa Framed Ceiling Uo
Cavity
 
 
 
 
 
Truss Span (ft)
 
 
 
 
 
R-value
12
14
16
18
20
22
24
26
28
30
32
34
36
19
0.1075
0.0991
0.0928
0.0878
0.0839
0.0807
0.0780
0.0757
0.0737
0.0720
0.0706
0.0693
0.0681
30
0.0907
0.0823
0.0760
0.0710
0.0671
0.0638
0.0612
0.0589
0.0569
0.0552
0.0538
0.0525
0.0513
38
0.0844
0.0759
0.0696
0.0647
0.0607
0.0575
0.0548
0.0525
0.0506
0.0489
0.0474
0.0461
0.0449
49
0.0789
0.0704
0.0641
0.0592
0.0552
0.0520
0.0493
0.0470
0.0451
0.0434
0.0419
0.0406
0.0395
Table A102.2.4(2)
Steel Trussa Framed Ceiling Uo with R-3 Sheathing
Cavity
 
 
 
 
 
Truss Span (ft)
 
 
 
 
 
R-value
12
14
16
18
20
22
24
26
28
30
32
34
36
19
0.0809
0.0763
0.0728
0.0701
0.0679
0.0661
0.0647
0.0634
0.0623
0.0614
0.0606
0.0599
0.0592
30
0.0641
0.0595
0.0560
0.0533
0.0511
0.0493
0.0478
0.0466
0.0455
0.0446
0.0438
0.0431
0.0424
38
0.0577
0.0531
0.0496
0.0469
0.0447
0.0430
0.0415
0.0402
0.0392
0.0382
0.0374
0.0367
0.0361
49
0.0523
0.0476
0.0441
0.0414
0.0393
0.0375
0.0360
0.0348
0.0337
0.0328
0.0319
0.0312
0.0306
Table A102.2.4(3)
Steel Trussa Framed Ceiling Uo with R-5 Sheathing
Cavity
 
 
 
 
 
Truss Span (ft)
 
 
 
 
 
R-value
12
14
16
18
20
22
24
26
28
30
32
34
36
19
0.0732
0.0697
0.0670
0.0649
0.0633
0.0619
0.0608
0.0598
0.0590
0.0583
0.0577
0.0571
0.0567
30
0.0564
0.0529
0.0502
0.0481
0.0465
0.0451
0.0440
0.0430
0.0422
0.0415
0.0409
0.0403
0.0399
38
0.0501
0.0465
0.0438
0.0418
0.0401
0.0388
0.0376
0.0367
0.0359
0.0351
0.0345
0.0340
0.0335
49
0.0446
0.0410
0.0384
0.0363
0.0346
0.0333
0.0322
0.0312
0.0304
0.0297
0.0291
0.0285
0.0280
Table A102.2.4(4)
Steel Trussa Framed Ceiling Uo with R-10 Sheathing
Cavity
 
 
 
 
 
Truss Span (ft)
 
 
 
 
 
R-value
12
14
16
18
20
22
24
26
28
30
32
34
36
19
0.0626
0.0606
0.0590
0.0578
0.0569
0.0561
0.0555
0.0549
0.0545
0.0541
0.0537
0.0534
0.0531
30
0.0458
0.0437
0.0422
0.0410
0.0401
0.0393
0.0387
0.0381
0.0377
0.0373
0.0369
0.0366
0.0363
38
0.0394
0.0374
0.0359
0.0347
0.0337
0.0330
0.0323
0.0318
0.0313
0.0309
0.0305
0.0302
0.0299
49
0.0339
0.0319
0.0304
0.0292
0.0283
0.0275
0.0268
0.0263
0.0258
0.0254
0.0251
0.0247
0.0245
Table A102.2.4(5)
Steel Trussa Framed Ceiling Uo with R-15 Sheathing
Cavity
 
 
 
 
 
Truss Span (ft)
 
 
 
 
 
R-value
12
14
16
18
20
22
24
26
28
30
32
34
36
19
0.0561
0.0550
0.0541
0.0535
0.0530
0.0526
0.0522
0.0519
0.0517
0.0515
0.0513
0.0511
0.0509
30
0.0393
0.0382
0.0373
0.0367
0.0362
0.0358
0.0354
0.0351
0.0349
0.0347
0.0345
0.0343
0.0341
38
0.0329
0.0318
0.0310
0.0303
0.0298
0.0294
0.0291
0.0288
0.0285
0.0283
0.0281
0.0279
0.0278
49
0.0274
0.0263
0.0255
0.0249
0.0244
0.0239
0.0236
0.0233
0.0230
0.0228
0.0226
0.0225
0.0223
 
Footnotes for Tables A102.2.4(1) through A102.2.4(5)
a
Assembly values based on 24 inch on center truss spacing; 11 Truss member connections penetrating insulation (4 at the eaves, 7 in the interior space); 1/2 inch drywall ceiling; all truss members are 2x4 "C" channels with a solid web.
b
Ceiling sheathing installed between bottom chord and drywall.
[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-610221, filed 2/1/13, effective 7/1/13.]