BASIC LOAD ESTIMATING

APPENDIX N

BASIC LOAD ESTIMATING

10 -0

12 -0

A

A

9 -0

8 -0

B

B

NOOK

2 -0 1ST FLOOR

PLAN VIEW

2ND FLOOR

FRONT SPAN

REAR SPAN

BEAM IN FAMILY ROOM PRIMARY LEVEL

SECONDARY LEVEL

BEAM IN NOOK

SECTION A-A

For SI: 1 inch = 25.4, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.

ASSUMPTIONS:

Loads

Secondary floor level is 30# L.L. + 10# D.L. = 40#/sq. ft.

Attic level is 20# live load + 10# dead load = 30#/sq. ft.

Nook ceiling is 10# dead load

= 10#/sq. ft.

Wall load Studs @ 16", 1/2" gypsum

Roof load

= 8#/sq. ft.

SECTION B-B

2006 NORTH CAROLINA RESIDENTIAL CODE

343

BASIC LOAD ESTIMATES

EXAMPLE OF LOAD ESTIMATING LOAD ON BEAM IN FAMILY ROOM

Loads in Section A - A as follows:

Total Loads

2nd floor load =

frontspan 2

+

rearspan 2

?

2nd floor

(deadload +

load)

=

LOAD / linear foot

=

120

+

12 2

?

40

=

11 ? 40 = 440#/1ft.

2nd floor = 440#/1ft.

Interior wall load = 8#/sq. ft. ? 8ft. (Ceiling height) = 64#/1ft.

Interior wall = 64#/1ft.

Attic load =

frontspan 2

+

rearspan 2

?

attic (deadload + live load)

=

= 120

+

12 2

?

30

= 11 ? 30 = 330#/linear ft.

Attic = 330#/1ft.

Roof load: No roof load is transmitted to the beam in the family room. Roof = 0 Total Load on Beam in Family Room = 834#/1ft.

Beam span in family room is 9 feet and total estimated load is 834#/linear foot:

By using Table No. N-1, the required beam is 4 @ 2" ? 12" Southern pine

OR

By using Table No. N-2, the required minimum flitch beam is 2 @ 2" ? 8" with 1/2" ? 7"steel plate bolted with 1/2" bolts spaced at 2' o.c.. EXAMPLE OF LOAD ESTIMATING ON BEAM IN NOOK AREA

Loads in Section B - B as follows

Total Loads

2nd floor load = joistspan ? 2nd floor (deadload + live load) = 12 ? 40 = 240#/1ft.

2

2

Wall load = 64#/1ft.

Wall load = 64#/1ft.

Attic floor load = joistspan ? Attic (deadload + live load) = 12 ? 30 = 180#/1ft.

2

2

Roof load = (rafter span + overhang) ? Roof (live load + dead load) =

= (12 + 1) ? 30 = 390#/1 ft.

Roof load = 390#/1 ft.

nook span

nook span

Nook roof load =

? roof load (live + dead) +

? ceiling dead load =

2

2

= 2 ? 30 + 2 ? 10 = 40#/1ft.

2

2

Nook = 40#/1ft.

Beam span in nook is 8 feet and total estimated load is 914#/linear foot.

Total Load on Beam in Nook = 914#/1 ft.

By using Table No. N-1, the required beam is 4 @ 2" ? 12 ? Southern pine, or 4 @ 2" ? 12" Spruce-pine-fir OR By using Table No. N-2, the required minimum flitch is 2 @ 2" ? 8" with 3/8" ? 7" steel plate bolted with 1/2" bolts spaced at 2" o.c.

For SI: 1 inch = 25.4, 1 foot = 304.8 mm.

344

2006 NORTH CAROLINA RESIDENTIAL CODE

BASIC LOAD ESTIMATES

TABLE N-1 WOOD BEAMS AND GIRDERS (19%) #2 GRADE, ALLOWABLE LOADS IN POUNDS PER LINEAR FOOT SIMPLE SPAN, DEFLECTION = L/360, LOAD DURATION FACTOR 1.0, ADEQUATE

BEARING AND LATERAL SUPPORT MUST BE PROVIDED

2 8 (11/2 71/4) SPECIES SPAN2

SPRUCE-PINE-FIR1 NUMBER OF MEMBERS

SOUTHERN PINE NUMBER OF MEMBERS

(feet)

2

3

4

2

3

4

3

1133

1700

2266

1457

2186

2914

4

727

1091

1454

935

1403

1870

5

535

803

1070

688

1032

1376

6

424

636

848

538

807

1076

7

350

525

700

400

600

800

8

270

405

540

309

464

618

9

215

323

430

246

369

492

10

175

263

350

200

300

400

12

107

161

214

123

185

246

14

68

102

136

78

117

156

2 10 (11/2 91/4) SPECIES SPAN2 (feet) 3 4 5 6 7 8 9 10 12 14

2 1776 1054 749 581 475 401 321 261 183 135

SPRUCE-PINE-FIR1 NUMBER OF MEMBERS

3 2664 1581 1124 872 713 602 482 392 275 203

4 3552 2108 1498 1162 950 802 642 522 366 270

2 2283 1355 963 747 570 440 350 285 200 147

SOUTHERN PINE NUMBER OF MEMBERS

3 3425 2033 1445 1121 855 660 525 428 300 221

4 4566 2710 1926 1494 1140 880 700 570 400 294

2 12 (11/2 111/4) SPECIES SPAN2 (feet) 3 4 5 6 7 8 9 10 12 14

2 2800 1482 1008 764 615 514 431 351 246 182

SPRUCE-PINE-FIR1 NUMBER OF MEMBERS

3 4200 2223 1512 1146 923 771 647 527 369 273

4 5600 2964 2016 1528 1230 1028 862 702 492 364

For SI: 1 foot = 304.8 mm. 1. Spruce-Pine-Fir not Spruce-pine-fir (Southern) is used in this table. 2. Span in clear span - effective span for bending and deflection is clear span plus 3 inch.

2 3600 1906 1296 982 783 604 481 392 274 203

SOUTHERN PINE NUMBER OF MEMBERS

3 5400 2859 1944 1473 1175 906 722 588 411 305

4 7200 3812 2592 1964 1566 1208 962 784 548 406

2006 NORTH CAROLINA RESIDENTIAL CODE

345

BASIC LOAD ESTIMATES

2 - 2 x 6 1

2 - 2 x 8 1

2 - 2 x 10 1

2 - 2 x 12 1

PLATE PLATE PLATE

PLATE

TABLE N-2 FLITCH PLATE BEAMS-DESIGN VALUES AND ASSUMPTIONS

Steel-

Fb = 24000(psi)

Wood-

Fb = 1200(psi)

Deflection-

1/360 of Span

(Top of Beam Laterally Supported)

Bm Wgt(lbs/ft) Span (ft) 6.00

Plate

E = 29000000(psi) E = 2900000(psi)

8

/1 4

x

5

756

ALLOWABLE LOAD (pounds/ft)

10

13

/3 8

x

5

/1 2

x

5

965

1175

7.00

555

709

863

8.00

411*

520*

638*

9.00

289*

365*

442*

10.00

210*

266*

322*

11.00

158*

200*

242*

12.00

122*

154*

187*

*Denotes Load Controlled by Deflection

Bm Wgt(lbs/ft) Span (ft)

Plate

11

/1 4

x

7

ALLOWABLE LOAD (pounds/ft)

14

17

/3 8

x

7

/1 2

x

7

6.00

1406

1818

2229

7.00

1033

1335

1637

8.00

791

1022

1254

9.00

625

808

991

10.00

506

654

802

11.00

400*

516*

631*

12.00

308*

397*

486*

13.00

243*

312*

382*

14.00

194*

250*

306*

15.00

158*

203*

249*

16.00

130*

168*

205*

*Denotes Load Controlled by Deflection

Bm Wgt(lbs/ft) Span(ft) 6.00

Plate

14

/1 4

x

9

2310

ALLOWABLE LOAD (pounds/ft)

18

22

/3 8

x

9

/1 2

x

9

2990

3669

7.00

1697

2197

2696

8.00

1299

1682

2064

9.00

1027

1329

1631

10.00

832

1076

1321

11.00

687

890

1092

12.00

576

747

917

13.00

492

637

782

14.00

409*

528*

647*

15.00

332*

429*

526*

16.00

274*

353*

433*

17.00

228*

295*

361*

18.00

192*

248*

304*

19.00

164*

211*

259*

20.00

140*

181*

222*

*Denotes Load Controlled by Deflection

Bm Wgt(lbs/ft) Span (ft)

Plate

18

/1 4

x

11

ALLOWABLE LOAD (pounds/ft)

22

27

/3 8

x

11

/1 2

x

11

6.00

3437

4452

5468

7.00

2525

3271

4017

8.00

1933

2504

3076

9.00

1528

1979

2430

10.00

1237

1603

1968

11.00

1023

1325

1627

12.00

859

1113

1367

13.00

732

948

1165

14.00

631

818

1004

15.00

550

712

875

16.00

483

626

769

17.00

414*

535*

657*

18.00

349*

451*

553*

19.00

297*

384*

470*

20.00

254*

329*

403*

21.00

220*

284*

348*

22.00

191*

247*

303*

23.00

167*

216*

265*

24.00

147*

190*

233*

*Denotes Load Controlled by Deflection

15

/5 8

x

5

1385

1018

739*

519*

378*

284*

219*

20

/5 8

x 7

2640

1939

1485

1173

950

746*

575*

452*

362*

294*

243*

26

/5 8

x 9

4349

3195

2446

1933

1566

1294

1087

926

765*

622*

513*

427*

360*

306*

263*

32

/5 8

x 11

6483

4763

3647

2881

2334

1929

1621

1381

1191

1037

912

778*

655*

557*

478*

413*

359*

314*

276*

17

/3 4

x

5

1595

1172

848*

596*

434*

326*

251*

23

/3 4

x

7

3051

2242

1716

1356

1098

862*

664*

522*

418*

340*

280*

30

/3 4

x

9

5029

3695

2829

2235

1810

1496

1257

1071

884*

719*

592*

494*

416*

354*

301*

36

/3 4

x

11

7498

5509

4218

3333

2699

2231

1875

1597

1377

1200

1054

899

757

644

552

477

415

363*

320

21 1 x 5 2014 1480 1067* 749* 546* 410* 316*

29 1 x 7 3873 2846 2179 1722 1394 1092* 841* 662* 530* 431* 355*

37 1 x 9 6388 4693 3593 2839 2300 1901 1597 1361 1122* 912* 752* 627* 528* 449* 385*

46 1 x 11 9529 7001 5360 4235 3430 2835 2382 2030 1750 1525 1340 1142* 962* 818* 701* 606* 527* 461* 406*

346

2006 NORTH CAROLINA RESIDENTIAL CODE

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download