Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11C - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial › Section 51-11C-610221 - Tables A102.2.4 - Steel truss framed ceiling U[o] values

Current through Register Vol. 24-14, July 15, 2024
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.
bCeiling sheathing
							 installed between bottom chord and drywall.
Statutory Authority:
				  RCW
				  19.27A.020,
				  19.27A.025 and
				  chapters
				  19.27 and
				  34.05 RCW. 13-04-056, §
				  51-11C-610221, filed 2/1/13, effective
				  7/1/13.