R802.11 Roof Tie-Down
RAFTER OR TRUSS UPLIFT CONNECTION FORCES FROM WIND (ASD) (POUNDS PER CONNECTION)a, b, c, d, e, f, g, h
RAFTER OR TRUSS SPACING | ROOF SPAN (feet) | EXPOSURE B | |||||||||
Ultimate Design Wind Speed VULT (mph) | |||||||||||
110 | 115 | 120 | 130 | 140 | |||||||
Roof Pitch | Roof Pitch | Roof Pitch | Roof Pitch | Roof Pitch | |||||||
< 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | ||
12" o.c. | 12 | 48 | 43 | 59 | 53 | 70 | 64 | 95 | 88 | 122 | 113 |
18 | 59 | 52 | 74 | 66 | 89 | 81 | 122 | 112 | 157 | 146 | |
24 | 71 | 62 | 89 | 79 | 108 | 98 | 149 | 137 | 192 | 178 | |
28 | 79 | 69 | 99 | 88 | 121 | 109 | 167 | 153 | 216 | 200 | |
32 | 86 | 75 | 109 | 97 | 134 | 120 | 185 | 170 | 240 | 222 | |
36 | 94 | 82 | 120 | 106 | 146 | 132 | 203 | 186 | 264 | 244 | |
42 | 106 | 92 | 135 | 120 | 166 | 149 | 230 | 211 | 300 | 278 | |
48 | 118 | 102 | 151 | 134 | 185 | 166 | 258 | 236 | 336 | 311 | |
16" o.c. | 12 | 64 | 57 | 78 | 70 | 93 | 85 | 126 | 117 | 162 | 150 |
18 | 78 | 69 | 98 | 88 | 118 | 108 | 162 | 149 | 209 | 194 | |
24 | 94 | 82 | 118 | 105 | 144 | 130 | 198 | 182 | 255 | 237 | |
28 | 105 | 92 | 132 | 117 | 161 | 145 | 222 | 203 | 287 | 266 | |
32 | 114 | 100 | 145 | 129 | 178 | 160 | 246 | 226 | 319 | 295 | |
36 | 125 | 109 | 160 | 141 | 194 | 176 | 270 | 247 | 351 | 325 | |
42 | 141 | 122 | 180 | 160 | 221 | 198 | 306 | 281 | 399 | 370 | |
48 | 157 | 136 | 201 | 178 | 246 | 221 | 343 | 314 | 447 | 414 | |
24" o.c. | 12 | 96 | 86 | 118 | 106 | 140 | 128 | 190 | 176 | 244 | 226 |
18 | 118 | 104 | 148 | 132 | 178 | 162 | 244 | 224 | 314 | 292 | |
24 | 142 | 124 | 178 | 158 | 216 | 196 | 298 | 274 | 384 | 356 | |
28 | 158 | 138 | 198 | 176 | 242 | 218 | 334 | 306 | 432 | 400 | |
32 | 172 | 150 | 218 | 194 | 268 | 240 | 370 | 340 | 480 | 444 | |
36 | 188 | 164 | 240 | 212 | 292 | 264 | 406 | 372 | 528 | 488 | |
42 | 212 | 184 | 270 | 240 | 332 | 298 | 460 | 422 | 600 | 556 | |
48 | 236 | 204 | 302 | 268 | 370 | 332 | 516 | 472 | 672 | 622 | |
RAFTER OR TRUSS SPACING | ROOF SPAN (feet) | EXPOSURE C | |||||||||
Ultimate Design Wind Speed VULT (mph) | |||||||||||
110 | 115 | 120 | 130 | 140 | |||||||
Roof Pitch | Roof Pitch | Roof Pitch | Roof Pitch | Roof Pitch | |||||||
< 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | < 5:12 | ≥ 5:12 | ||
12" o.c. | 12 | 95 | 88 | 110 | 102 | 126 | 118 | 161 | 151 | 198 | 186 |
18 | 121 | 111 | 141 | 131 | 163 | 151 | 208 | 195 | 257 | 242 | |
24 | 148 | 136 | 173 | 160 | 200 | 185 | 256 | 239 | 317 | 298 | |
28 | 166 | 152 | 195 | 179 | 225 | 208 | 289 | 269 | 358 | 335 | |
32 | 184 | 168 | 216 | 199 | 249 | 231 | 321 | 299 | 398 | 373 | |
36 | 202 | 185 | 237 | 219 | 274 | 254 | 353 | 329 | 438 | 411 | |
42 | 229 | 210 | 269 | 248 | 312 | 289 | 402 | 375 | 499 | 468 | |
48 | 256 | 234 | 302 | 278 | 349 | 323 | 450 | 420 | 560 | 524 | |
16" o.c. | 12 | 126 | 117 | 146 | 136 | 168 | 157 | 214 | 201 | 263 | 247 |
18 | 161 | 148 | 188 | 174 | 217 | 201 | 277 | 259 | 342 | 322 | |
24 | 197 | 181 | 230 | 213 | 266 | 246 | 340 | 318 | 422 | 396 | |
28 | 221 | 202 | 259 | 238 | 299 | 277 | 384 | 358 | 476 | 446 | |
32 | 245 | 223 | 287 | 265 | 331 | 307 | 427 | 398 | 529 | 496 | |
36 | 269 | 246 | 315 | 291 | 364 | 338 | 469 | 438 | 583 | 547 | |
42 | 305 | 279 | 358 | 330 | 415 | 384 | 535 | 499 | 664 | 622 | |
48 | 340 | 311 | 402 | 370 | 464 | 430 | 599 | 559 | 745 | 697 | |
24" o.c. | 12 | 190 | 176 | 220 | 204 | 252 | 236 | 322 | 302 | 396 | 372 |
18 | 242 | 222 | 282 | 262 | 326 | 302 | 416 | 390 | 514 | 484 | |
24 | 296 | 272 | 346 | 320 | 400 | 370 | 512 | 478 | 634 | 596 | |
28 | 332 | 304 | 390 | 358 | 450 | 416 | 578 | 538 | 716 | 670 | |
32 | 368 | 336 | 432 | 398 | 498 | 462 | 642 | 598 | 796 | 746 | |
36 | 404 | 370 | 474 | 438 | 548 | 508 | 706 | 658 | 876 | 822 | |
42 | 458 | 420 | 538 | 496 | 624 | 578 | 804 | 750 | 998 | 936 | |
48 | 512 | 468 | 604 | 556 | 698 | 646 | 900 | 840 | 1120 | 1048 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound = 0.454 kg, 1 pound per square foot = 47.9 N/m2, 1 pound per linear foot = 14.6 N/m.
- The uplift connection forces are based on a maximum 33-foot mean roof height and Wind Exposure Category B or C. For Exposure D, the uplift connection force shall be selected from the Exposure C portion of the table using the next highest tabulated ultimate design wind speed. The adjustment coefficients in Table R301.2(3) shall not be used to multiply the tabulated forces for Exposures C and D or for other mean roof heights.
- The uplift connection forces include an allowance for roof and ceiling assembly dead load of 15 psf.
- The tabulated uplift connection forces are limited to a maximum roof overhang of 24 inches.
- The tabulated uplift connection forces shall be permitted to be multiplied by 0.75 for connections not located within 8 feet of building corners.
- For buildings with hip roofs with 5:12 and greater pitch, the tabulated uplift connection forces shall be permitted to be multiplied by 0.70. This reduction shall not be combined with any other reduction in tabulated forces.
- For wall-to-wall and wall-to-foundation connections, the uplift connection force shall be permitted to be reduced by 60 plf for each full wall above.
- Linear interpolation between tabulated roof spans and wind speeds shall be permitted.
- The tabulated forces for a 12-inch on-center spacing shall be permitted to be used to determine the uplift load in pounds per linear foot.
Roof assemblies shall have uplift resistance in accordance with Sections R802.11.1.1 and R802.11.1.2.
Where the uplift force does not exceed 200 pounds (90.8 kg), rafters and trusses spaced not more than 24 inches (610 mm) on center shall be permitted to be attached to their supporting wall assemblies in accordance with Table R602.3(1).
Where the basic wind speed does not exceed 115 mph, the wind exposure category is B, the roof pitch is 5:12 (42-percent slope) or greater, and the roof span is 32 feet (9754 mm) or less, rafters and trusses spaced not more than 24 inches (610 mm) on center shall be permitted to be attached to their supporting wall assemblies in accordance with Table R602.3(1).