ADOPTS WITH AMENDMENTS:

International Residential Code 2018 (IRC 2018)

Part I — Administrative

Part II — Definitions

Part III — Building Planning and Construction

Part IV — Energy Conservation

Part V — Mechanical

Part VI — Fuel Gas

Part VII — Plumbing

Part VIII — Electrical

Part IX — Referenced Standards

Heads up: There are no amended sections in this chapter.

The provisions of this chapter shall control the design and construction of the foundation and foundation spaces for buildings. In addition to the provisions of this chapter, the design and construction of foundations in flood hazard areas as established by Table R301.2(1) shall meet the provisions of Section R322. Wood foundations shall be designed and installed in accordance with AWC PWF.

Exception: The provisions of this chapter shall be permitted to be used for wood foundations only in the following situations:

  1. In buildings that have no more than two floors and a roof.
  2. Where interior basement and foundation walls are constructed at intervals not exceeding 50 feet (15 240 mm).
  3. Buildings and structures located within the High-Velocity Hurricane Zone shall comply with the provisions of Chapter 44 and, as applicable, Section R322 in flood hazard areas.

Wood foundations in Seismic Design Category D0, D1 or D2 shall be designed in accordance with accepted engineering practice.

TABLE R401.1

FOUNDATION UPLIFT LIGHT STEEL & WOOD FRAME BUILDINGS IN EXPOSURE B (plf)5, 6

Roof
Angle
Bldg Width Minimum
Building Length
Vasd as determined in accordance with Section R301.2.1.3 / Velocity Pressure
100 110 120 130 140 150
15 18 22 26 30 34
45 3 Stories3 20 12 173 276 389 512 644 787
25 14 73 165 265 374 492 618
30 19 0 81 174 275 384 502
35 25 17 48 104 200 305 417
40 35 33 69 109 152 240 349
2 Stories2 20 12 64 126 195 270 350 437
25 15 17 66 129 198 272 352
30 22 38 62 90 146 217 294
35 35 56 86 118 154 192 252
40 40 74 108 146 186 230 277
1 Story1 20 12 33 46 61 94 132 173
25 22 57 75 96 118 142 167
30 18 79 103 129 157 187 219
35 16 100 128 159 192 229 267
40 16 120 152 188 226 268 312
30 3 Stories3 20 12 92 177 271 373 483 601
25 17 0 63 143 230 324 425
30 25 0 23 52 125 209 300
35 35 13 44 78 115 154 206
40 40 28 64 102 145 190 239
2 Stories2 20 13 1 50 103 162 224 292
25 23 16 35 57 84 139 199
30 30 36 60 87 116 148 181
35 35 54 83 115 150 187 227
40 36 71 104 141 181 224 270
1 Story1 20 20 32 46 60 76 93 112
25 15 56 74 95 117 140 166
30 13 78 102 127 155 185 217
35 14 99 127 157 190 226 264
40 16 118 150 185 223 264 308
20 3 Stories3 20 12 113 203 301 408 523 647
25 14 45 130 222 322 431 547
30 17 4 85 177 277 385 501
35 19 20 58 154 257 369 489
40 21 35 72 141 249 367 493
2 Stories2 20 12 43 100 163 231 304 384
25 13 22 79 143 214 289 371
30 15 42 72 141 217 298 386
35 15 61 92 150 232 321 417
40 16 78 114 164 254 352 457
1 Story1 20 12 38 57 94 135 179 226
25 12 62 82 122 171 223 280
30 12 85 110 154 212 275 342
35 14 107 136 190 257 330 409
40 16 126 160 227 304 388 478

TABLE R401.1—continued

FOUNDATION UPLIFT LIGHT STEEL & WOOD FRAME BUILDINGS IN EXPOSURE C (plf)5, 6

Roof
Angle
Bldg Width Minimum
Building Length4
Vasd as determined in accordance with Section R301.2.1.3 / Velocity Pressure
100 110 120 130 140 150
21 26 31 36 42 48
45 3 Stories3 20 12 370 515 673 845 1031 1231
25 13 249 377 518 670 836 1013
30 17 159 278 408 550 703 867
35 21 89 203 328 463 610 767
40 26 102 153 262 394 537 691
2 Stories2 20 12 184 271 368 472 585 706
25 13 119 200 288 385 489 601
30 18 85 147 233 326 426 533
35 24 113 155 200 284 383 489
40 36 139 187 240 297 358 457
1 Story1 20 12 58 95 140 189 243 300
25 16 92 118 147 178 224 281
30 19 124 157 193 233 275 321
35 17 154 193 236 283 334 388
40 16 182 227 277 331 389 452
30 3 Stories3 20 12 256 376 507 650 804 970
25 15 130 232 344 466 598 740
30 21 47 127 228 337 455 582
35 31 72 116 163 241 351 469
40 40 96 146 200 259 323 392
2 Stories2 20 12 95 163 238 320 408 502
25 18 53 85 151 223 301 385
30 30 83 117 154 195 239 304
35 35 110 150 195 244 296 353
40 37 135 182 233 289 350 415
1 Story1 20 20 58 76 97 119 143 169
25 16 91 117 145 176 210 245
30 13 123 156 191 230 272 317
35 14 152 191 234 280 330 384
40 16 179 224 273 327 384 446
20 3 Stories3 20 12 285 411 549 698 860 1034
25 13 207 325 455 595 748 911
30 15 162 280 409 549 701 863
35 17 138 260 393 538 695 863
40 18 124 252 392 545 709 886
2 Stories2 20 12 152 233 320 416 519 630
25 12 133 215 306 404 511 625
30 13 130 219 316 422 536 658
35 14 138 235 341 456 581 715
40 16 150 257 373 500 636 783
1 Story1 20 12 88 136 188 245 307 373
25 12 114 172 235 303 377 457
30 12 146 214 288 370 457 552
35 14 180 259 346 441 543 653
40 16 215 306 406 515 632 758

Notes:

  1. Based on 1st floor height = 10 ft. or 11 ft. floor to floor in multistory.
  2. Based on 2nd floor height = 8 ft. or 9 ft. floor to floor in multistory.
  3. Based on 3rd floor height = 8 ft.
  4. Building length shall be equal to or greater than that shown in tables.
  5. Roof and floor framing shall span in the same direction.
  6. Includes provision for 2 foot roof overhang.
Foundations shall be capable of resisting all loads from roof uplift and building overturn. Foundation uplift for light-frame wood or steel buildings shall be calculated or determined from Table R401.1. Masonry buildings within the dimensional scope of Table R401.1 shall be assumed to be of adequate weight so as not to require uplift resistance greater than that provided by the structure and any normal foundation. Foundation construction shall also be capable of accommodating all gravity loads in accordance with Section R301 and of transmitting the resulting loads to the supporting soil. Fill soils that support footings and foundations shall be designed, installed and tested in accordance with accepted engineering practice. Gravel fill used as footings for wood and precast concrete foundations shall comply with Section R403.

R401.3 Drainage

ILLUSTRATION

Surface drainage shall be diverted to a storm sewer conveyance or other approved point of collection that does not create a hazard. Lots shall be graded to drain surface water away from foundation walls. The grade shall fall a minimum of 6 inches (152 mm) within the first 10 feet (3048 mm).

Exception: Where lot lines, walls, slopes or other physical barriers prohibit 6 inches (152 mm) of fall within 10 feet (3048 mm), drains or swales shall be constructed to ensure drainage away from the structure. Impervious surfaces within 10 feet (3048 mm) of the building foundation shall be sloped a minimum of 2 percent away from the building.

Where quantifiable data created by accepted soil science methodologies indicate expansive, compressible, shifting or other questionable soil characteristics are likely to be present, the building official shall determine whether to require a soil test to determine the soil's characteristics at a particular location. This test shall be done by an approved agency using an approved method.

In lieu of a complete geotechnical evaluation, the load-bearing values in Table R401.4.1 shall be assumed.

TABLE R401.4.1

PRESUMPTIVE LOAD-BEARING VALUES OF FOUNDATION MATERIALSa

CLASS OF MATERIAL LOAD-BEARING
PRESSURE
(pounds per square foot)
Crystalline bedrock 12,000
Sedimentary and foliated rock 4,000
Sandy gravel and/or gravel (GW and GP) 3,000
Sand, silty sand, clayey sand, silty gravel
and clayey gravel (SW, SP, SM, SC, GM
and GC)
2,000
Clay, sandy, silty clay, clayey silt, silt and
sandy siltclay (CL, ML, MH and CH)
1,500b

For SI: 1 pound per square foot = 0.0479 kPa.

  1. Where soil tests are required by Section R401.4, the allowable bearing capacities of the soil shall be part of the recommendations.
  2. Where the building official determines that in-place soils with an allowable bearing capacity of less than 1,500 psf are likely to be present at the site, the allowable bearing capacity shall be determined by a soils investigation.
Instead of a complete geotechnical evaluation, where top or subsoils are compressible or shifting, they shall be removed to a depth and width sufficient to ensure stable moisture content in each active zone and shall not be used as fill or stabilized within each active zone by chemical, dewatering or presaturation.
Wood foundation systems shall be designed and installed in accordance with the provisions of this code.
Fasteners used below grade to attach plywood to the exterior side of exterior basement or crawl-space wall studs, or fasteners used in knee wall construction, shall be of Type 304 or 316 stainless steel. Fasteners used above grade to attach plywood and all lumber-to-lumber fasteners except those used in knee wall construction shall be of Type 304 or 316 stainless steel, silicon bronze, copper, hot-dipped galvanized (zinc coated) steel nails, or hot-tumbled galvanized (zinc coated) steel nails. Electro-galvanized steel nails and galvanized (zinc coated) steel staples shall not be permitted.
All lumber and plywood shall be pressure-preservative treated and dried after treatment in accordance with AWPA U1 (Commodity Specification A, Special Requirement 4.2) and shall bear the label of an accredited agency. Where lumber and/or plywood is cut or drilled after treatment, the treated surface shall be field treated with copper naphthenate, the concentration of which shall contain a minimum of 2-percent copper metal, by repeated brushing, dipping or soaking until the wood absorbs no more preservative.

R402.2 Concrete

ILLUSTRATION

Concrete shall have a minimum specified compressive strength of f 'c, as shown in Table R402.2. Concrete subject to moderate or severe weathering as indicated in Table R301.2(1) shall be air entrained as specified in Table R402.2. The maximum weight of fly ash, other pozzolans, silica fume, slag or blended cements that is included in concrete mixtures for garage floor slabs and for exterior porches, carport slabs and steps that will be exposed to deicing chemicals shall not exceed the percentages of the total weight of cementitious materials specified in Section 19.3.3.4 of ACI 318. Materials used to produce concrete and testing thereof shall comply with the applicable standards listed in Chapters 19 and 20 of ACI 318 or ACI 332.

TABLE R402.2

MINIMUM SPECIFIED COMPRESSIVE STRENGTH OF CONCRETE

TYPE OR LOCATION OF CONCRETE CONSTRUCTION MINIMUM SPECIFIED COMPRESSIVE STRENGTHa (f'c)
Weathering Potentialb
Negligible Moderate Severe
Basement walls, foundations and other concrete not exposed to the weather 2,500 2,500 2,500c
Basement slabs and interior slabs on grade, except garage floor slabs 2,500 2,500 2,500c
Basement walls, foundation walls, exterior walls and other vertical concrete
work exposed to the weather
2,500 3,000d 3,000d
Porches, carport slabs and steps exposed to the weather, and garage floor
slabs
2,500 3,000d, e, f 3,500d, e, f

For SI: 1 pound per square inch = 6.895 kPa.

  1. Strength at 28 days psi.
  2. See Table R301.2(1) for weathering potential.
  3. Concrete in these locations that is subject to freezing and thawing during construction shall be air-entrained concrete in accordance with Footnote d.
  4. Concrete shall be air-entrained. Total air content (percent by volume of concrete) shall be not less than 5 percent or more than 7 percent.
  5. See Section R402.2 for maximum cementitious materials content.
  6. For garage floors with a steel-troweled finish, reduction of the total air content (percent by volume of concrete) to not less than 3 percent is permitted if the specified compressive strength of the concrete is increased to not less than 4,000 psi.
Materials for concrete shall comply with the requirements of Section R608.5.1.
Precast concrete foundations shall be designed in accordance with Section R404.5 and shall be installed in accordance with the provisions of this code and the manufacturer's instructions.

Materials used to produce precast concrete foundations shall meet the following requirements.

  1. All concrete used in the manufacture of precast concrete foundations shall have a minimum compressive strength of 5,000 psi (34 470 kPa) at 28 days. Concrete exposed to a freezing and thawing environment shall be air entrained with a minimum total air content of 5 percent.
  2. Structural reinforcing steel shall meet the requirements of ASTM A615, A706 or A996. The minimum yield strength of reinforcing steel shall be 40,000 psi (Grade 40) (276 MPa). Steel reinforcement for precast concrete foundation walls shall have a minimum concrete cover of 3/4 inch (19.1 mm).
  3. Panel-to-panel connections shall be made with Grade II steel fasteners.
  4. The use of nonstructural fibers shall conform to ASTM C1116.
  5. Grout used for bedding precast foundations placed upon concrete footings shall meet ASTM C1107.
Masonry systems shall be designed and installed in accordance with this chapter and shall have a minimum specified compressive strength of 1,500 psi (10.3 MPa).

Section R403 Footings

ILLUSTRATION

R403.1 General

ILLUSTRATION

All exterior walls shall be supported on continuous solid or fully grouted masonry or concrete footings, crushed stone footings, wood foundations, or other approved structural systems which shall be of sufficient design to accommodate all loads according to Section R301 and to transmit the resulting loads to the soil within the limitations as determined from the character of the soil. Footings shall be supported on undisturbed natural soils or engineered fill. Concrete footing shall be designed and constructed in accordance with the provisions of Section R403 or in accordance with ACI 332.

TABLE R403.1(1)

MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS FOR LIGHT-FRAME CONSTRUCTION (inches)a, b

SNOW LOAD
OR ROOF LIVE
LOAD
STORY AND TYPE
OF STRUCTURE WITH
LIGHT FRAME
LOAD-BEARING VALUE OF SOIL
(psf)
1500 2000 2500 3000 3500 4000
20 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 22 × 6 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
3 story—slab-on-grade 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—plus basement 25 × 8 19 × 6 15 × 6 13 × 6 12 × 6 12 × 6
30 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 23 × 6 17 × 6 14 × 6 12 × 6 12 × 6 12 × 6
3 story—slab-on-grade 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—plus basement 26 × 8 20 × 6 16 × 6 13 × 6 12 × 6 12 × 6
50 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 21 × 6 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 25 × 7 19 × 6 15 × 6 12 × 6 12 × 6 12 × 6
3 story—slab-on-grade 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 22 × 6 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6
3 story—plus basement 28 × 9 21 × 6 17 × 6 14 × 6 12 × 6 12 × 6
70 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 18 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 24 × 7 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 21 × 6 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 27 × 9 20 × 6 16 × 6 14 × 6 12 × 6 12 × 6
3 story—slab-on-grade 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 25 × 7 18 × 6 15 × 6 12 × 6 12 × 6 12 × 6
3 story—plus basement 30 × 10 23 × 6 18 × 6 15 × 6 13 × 6 12 × 6

For SI: 1 inch = 25.4 mm, 1 plf = 14.6 N/m, 1 pound per square foot = 47.9 N/m2.

  1. Interpolation allowed. Extrapolation is not allowed.
  2. Based on 32-foot-wide house with load-bearing center wall that carries half of the tributary attic, and floor framing. For every 2 feet of adjustment to the width of the house, add or subtract 2 inches of footing width and 1 inch of footing thickness (but not less than 6 inches thick).

TABLE R403.1(2)

MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS FOR LIGHT-FRAME CONSTRUCTION WITH BRICK VENEER (inches)a, b

SNOW LOAD
OR ROOF LIVE
LOAD
STORY AND TYPE OF
STRUCTURE
WITH BRICK VENEER
LOAD-BEARING VALUE OF SOIL
(psf)
1500 2000 2500 3000 3500 4000
20 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 21 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 26 × 8 20 × 6 16 × 6 13 × 6 12 × 6 12 × 6
3 story—slab-on-grade 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 26 × 8 19 × 6 15 × 6 13 × 6 12 × 6 12 × 6
3 story—plus basement 32 × 11 24 × 7 19 × 6 16 × 6 14 × 6 12 × 6
30 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 22 × 6 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 22 × 6 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 27 × 9 21 × 6 16 × 6 14 × 6 12 × 6 12 × 6
3 story—slab-on-grade 21 × 6 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 27 × 8 20 × 6 16 × 6 13 × 6 12 × 6 12 × 6
3 story—plus basement 33 × 11 24 × 7 20 × 6 16 × 6 14 × 6 12 × 6
50 psf 1 story—slab-on-grade 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 24 × 7 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6
2 story—slab-on-grade 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 24 × 7 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6
2 story—plus basement 29 × 10 22 × 6 18 × 6 15 × 6 13 × 6 12 × 6
3 story—slab-on-grade 27 × 7 18 × 6 13 × 6 12 × 6 12 × 6 12 × 6
3 story—with crawl space 29 × 9 22 × 6 17 × 6 14 × 6 12 × 6 12 × 6
3 story—plus basement 35 × 12 26 × 8 21 × 6 17 × 6 15 × 6 13 × 6
70 psf 1 story—slab-on-grade 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 26 × 8 20 × 6 16× 6 13 × 6 12 × 6 12 × 6
2 story—slab-on grade 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 26 × 8 19 × 6 15× 6 13 × 6 12 × 6 12 × 6
2 story—plus basement 32 × 11 24 × 7 19 × 6 16 × 6 14 × 6 12 × 6
3 story—slab-on-grade 26 × 8 19 × 6 15 × 6 13 × 6 12 × 6 12 × 6
3 story—with crawl space 31 × 11 23 × 7 19 × 6 16 × 6 13 × 6 12 × 6
3 story—plus basement 37 × 13 28 × 9 22 × 6 18 × 6 16 × 6 14 × 6

For SI: 1 inch = 25.4 mm, 1 plf = 14.6 N/m, 1 pound per square foot = 47.9 N/m2.

  1. Interpolation allowed. Extrapolation is not allowed.
  2. Based on 32-foot-wide house with load-bearing center wall that carries half of the tributary attic, and floor framing. For every 2 feet of adjustment to the width of the house, add or subtract 2 inches of footing width and 1 inch of footing thickness (but not less than 6 inches thick).

TABLE R403.1(3)

MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS WITH CAST-IN-PLACE CONCRETE OR FULLY GROUTED MASONRY WALL CONSTRUCTION (inches)a, b

SNOW LOAD
OR ROOF LIVE
LOAD
STORY AND TYPE
OF STRUCTURE WITH CMU
LOAD-BEARING VALUE OF SOIL
(psf)
1500 2000 2500 3000 3500 4000
20 psf 1 story—slab-on-grade 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 25 × 8 19 × 6 15 × 6 13 × 6 12 × 6 12 × 6
2 story—slab-on-grade 23 × 7 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 29 × 9 22 × 6 17 × 6 14 × 6 12 × 6 12 × 6
2 story—plus basement 35 × 12 26 × 8 21 × 6 17 × 6 15 × 6 13 × 6
3 story—slab-on-grade 32 × 11 24 × 7 19 × 6 16 × 6 14 × 6 12 × 6
3 story—with crawl space 38 × 14 28 × 9 23 × 6 19 × 6 16 × 6 14 × 6
3 story—plus basement 43 × 17 33 × 11 26 × 8 22 × 6 19 × 6 16 × 6
30 psf 1 story—slab-on-grade 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 26 × 8 20 × 6 16 × 6 13 × 6 12 × 6 12 × 6
2 story—slab-on-grade 24 × 7 18 × 6 15 × 6 12 × 6 12 × 6 12 × 6
2 story—with crawl space 30 × 10 22 × 6 18 × 6 15 × 6 13 × 6 12 × 6
2 story—plus basement 36 × 13 27 × 8 21 × 6 18 × 6 15 × 6 13 × 6
3 story—slab-on-grade 33 × 12 25 × 7 20 × 6 17 × 6 14 × 6 12 × 6
3 story—with crawl space 39 × 14 29 × 9 23 × 7 19 × 6 17 × 6 14 × 6
3 story—plus basement 44 × 17 33 × 12 27× 8 22 × 6 19 × 6 17 × 6
50 psf 1 story—slab-on-grade 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 22 × 6 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 28× 9 21 × 6 17 × 6 14 × 6 12 × 6 12 × 6
2 story—slab-on-grade 27 × 8 20 × 6 16 × 6 13 × 6 12 × 6 12 × 6
2 story—with crawl space 32 × 11 24 × 7 19 × 6 16 × 6 14 × 6 12 × 6
2 story—plus basement 38 × 14 28 × 9 23 × 6 19 × 6 16 × 6 14 × 6
3 story—slab-on-grade 35 × 13 27 × 8 21 × 6 18 × 6 15 × 6 13 × 6
3 story—with crawl space 41 × 15 31 × 10 24 × 7 20 × 6 17 × 6 15 × 6
3 story—plus basement 47 × 18 35 × 12 28 × 9 23 × 7 20 × 6 17 × 6
70 psf 1 story—slab-on-grade 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
1 story—with crawl space 25 × 7 18 × 6 15 × 6 12 × 6 12 × 6 12 × 6
1 story—plus basement 30 × 10 23 × 6 18 × 6 15 × 6 13 × 6 12 × 6
2 story—slab-on-grade 29 × 9 22 × 6 17 × 6 14 × 6 12 × 6 12 × 6
2 story—with crawl space 34 × 12 26 × 8 21 × 6 17 × 6 15 × 6 13 × 6
2 story—plus basement 40 × 15 30 × 10 24 × 7 20 × 6 17 × 6 15 × 6
3 story—slab-on-grade 38 × 14 28 × 9 23 × 6 19 × 6 16 × 6 14 × 6
3 story—with crawl space 43 × 16 32 × 11 26 × 8 21 × 6 18 × 6 16 × 6
3 story—plus basement 49 × 19 37 × 13 29 × 10 24 × 7 21 × 6 18 × 6

For SI: 1 inch = 25.4 mm, 1 plf = 14.6 N/m, 1 pound per square foot = 47.9 N/m2.

  1. Interpolation allowed. Extrapolation is not allowed.
  2. Based on 32-foot-wide house with load-bearing center wall that carries half of the tributary attic, and floor framing. For every 2 feet of adjustment to the width of the house add or subtract 2 inches of footing width and 1 inch of footing thickness (but not less than 6 inches thick).

FIGURE 403.1(1)

CONCRETE AND MASONRY FOUNDATION DETAILS

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mil = 0.0254.

FIGURE R403.1(2)

PERMANENT WOOD FOUNDATION BASEMENT WALL SECTION

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.

FIGURE R403.1(3)

PERMANENT WOOD FOUNDATION CRAWL SPACE SECTION

The minimum width, W, and thickness, T, for concrete footings shall be in accordance with Tables R403.1(1) through R403.1(3) and Figure R403.1(1) as applicable. Minimum sizes for concrete and masonry footings shall also be required to provide adequate resistance to uplift and overturn of the building as determined from Table R401.1 and Section R403.1.2 or as calculated using engineered design in accordance with the Florida Building Code, Building. The footing width shall be based on the load-bearing value of the soil in accordance with Table R401.4.1. Footing projections, P, shall be not less than 2 inches (51 mm) and shall not exceed the thickness of the footing. Footing thickness and projection for fireplaces shall be in accordance with Section R1001.2. The size of footings supporting piers and columns shall be based on the tributary load and allowable soil pressure in accordance with Table R401.4.1. Footings for wood foundations shall be in accordance with the details set forth in Section R403.2, and Figures R403.1(2) and R403.1(3).

Uplift resistance of common foundations are given in Table R403.1.2. Uplift resistance of these foundations may be increased by increasing the size of the concrete footing. When determining the modified uplift resistance the added weight shall be reduced by multiplying by a factor of 0.6. Other foundation systems shall be engineered in accordance with the Florida Building Code, Building.

TABLE R403.1.2

FOUNDATION UPLIFT (ASD) DESIGN DETAILS

FOOTING TYPE T
(inches)
W
(inches)
SLAB/WALL1 RESISTANCE
(plf)
NOTES
A Mono 20 12 6 502 3
Mono 20 16 6 585 3
B Mono Interior 20 12 13 796 3
Mono Interior 20 16 13 879 3
C 12" Stem/Joist 10 20 228 436 1, 2, 3
D Mono 20 12 6 502
Mono 20 16 6 585
E Mono Interior 20 12 13 796
Mono Interior 20 16 13 879
F Stem/Joist 10 20 208 2, 3
G Stem/Slab 10 20 6 460 3
H Stem/Slab 10 12 6 377 3
Stem/Slab 10 20 6 460 3

For SI: 1 inch = 25.4 mm.

  1. Tributary width of 31/2" slab or weight of stemwall and bond beam.
  2. First floor dead load multiplied by 0.6 may also be included.
  3. All footing dowel bars shall be same size as wall steel, shall have a standard 90-degree hook, and shall be embedded a minimum of 6 inches. Dowel bars shall lap vertical wall reinforcement a minimum of 25 inches.
Reserved.
Exterior footings shall be placed not less than 12 inches (305 mm) below the finished grade of ground surface. Where applicable, the depth of footings shall also conform to Section R403.1.4.1.

Except where otherwise protected from frost, foundation walls, piers and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods:

  1. Extended below the frost line specified in Table R301.2.(1).
  2. Constructed in accordance with Section R403.3.
  3. Constructed in accordance with ASCE 32.
  4. Erected on solid rock.

Exceptions:

  1. Protection of free-standing accessory structures with an area of 600 square feet (56 m2) or less, of light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.
  2. Protection of free-standing accessory structures with an area of 400 square feet (37 m2) or less, of other than light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.
  3. Decks not supported by a dwelling need not be provided with footings that extend below the frost line.

Footings shall not bear on frozen soil unless the frozen condition is permanent.

R403.1.5 Slope

ILLUSTRATION
The top surface of footings shall be level. The bottom surface of footings shall not have a slope exceeding one unit vertical in 10 units horizontal (10-percent slope). Footings shall be stepped where it is necessary to change the elevation of the top surface of the footings or where the slope of the bottom surface of the footings will exceed one unit vertical in 10 units horizontal (10-percent slope).

Wood sill plates and wood walls supported directly on continuous foundations shall be anchored to the foundation in accordance with this section.

Cold-formed steel framing shall be anchored directly to the foundation or fastened to wood sill plates in accordance with AISI S230. Wood sill plates supporting cold-formed steel framing shall be anchored to the foundation in accordance with this section.

Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation in accordance with the AWC WFCM. Sill plates and sole plates shall be protected against decay and termites where required by Sections R317 and R318.

In addition to the requirements of Section R403.1.6, the following requirements shall apply to wood light-frame structures in Seismic Design Categories D0, D1 and D2 and wood light-frame townhouses in Seismic Design Category C.

  1. Plate washers not less than 0.229 inch by 3 inches by 3 inches (5.8 mm by 76 mm by 76 mm) in size shall be provided for all anchor bolts over the full length of required braced wall lines except where approved anchor straps are used. Properly sized cut washers shall be permitted for anchor bolts in wall lines not containing braced wall panels. The hole in the plate washer is permitted to be diagonally slotted with a width of up to 3/16 inch (5 mm) larger than the bolt diameter and a slot length not to exceed 13/4 inches (44 mm), provided that a standard cut washer is placed between the plate washer and the nut.
  2. Interior braced wall plates shall have anchor bolts spaced at not more than 6 feet (1829 mm) on center and located within 12 inches (305 mm) of the ends of each plate section when supported on a continuous foundation.
  3. Interior bearing wall sole plates shall have anchor bolts spaced at not more than 6 feet (1829 mm) on center and located within 12 inches (305 mm) of the ends of each plate section when supported on a continuous foundation.
  4. The maximum anchor bolt spacing shall be 4 feet (1219 mm) for buildings over two stories in height.
  5. Stepped cripple walls shall comply with Section R602.3.
  6. Where continuous wood foundations in accordance with Section R404.2 are used, the force transfer shall have a capacity equal to or greater than the connections required by Item 1 of this section or the braced wall panel shall be connected to the wood foundations in accordance with the braced wall panel-to-floor fastening requirements of Section R602.3.
The placement of buildings and structures on or adjacent to slopes steeper than one unit vertical in three units horizontal (33.3-percent slope) shall conform to Sections R403.1.7.1 through R403.1.7.4.

In general, buildings below slopes shall be set a sufficient distance from the slope to provide protection from slope drainage, erosion and shallow failures. Except as provided in Section R403.1.7.4 and Figure R403.1.7.1, the following criteria will be assumed to provide this protection. Where the existing slope is steeper than one unit vertical in one unit horizontal (100-percent slope), the toe of the slope shall be assumed to be at the intersection of a horizontal plane drawn from the top of the foundation and a plane drawn tangent to the slope at an angle of 45 degrees (0.79 rad) to the horizontal. Where a retaining wall is constructed at the toe of the slope, the height of the slope shall be measured from the top of the wall to the top of the slope.

For SI: 1 foot = 304.8 mm.

FIGURE R403.1.7.1

FOUNDATION CLEARANCE FROM SLOPES

Footings on or adjacent to slope surfaces shall be founded in material with an embedment and setback from the slope surface sufficient to provide vertical and lateral support for the footing without detrimental settlement. Except as provided for in Section R403.1.7.4 and Figure R403.1.7.1, the following setback is deemed adequate to meet the criteria. Where the slope is steeper than one unit vertical in one unit horizontal (100-percent slope), the required setback shall be measured from an imaginary plane 45 degrees (0.79 rad) to the horizontal, projected upward from the toe of the slope.
On graded sites, the top of any exterior foundation shall extend above the elevation of the street gutter at point of discharge or the inlet of an approved drainage device a minimum of 12 inches (305 mm) plus 2 percent. Alternate elevations are permitted subject to the approval of the building official, provided it can be demonstrated that required drainage to the point of discharge and away from the structure is provided at all locations on the site.
Alternate setbacks and clearances are permitted, subject to the approval of the building official. The building official is permitted to require an investigation and recommendation of a qualified engineer to demonstrate that the intent of this section has been satisfied. Such an investigation shall include consideration of material, height of slope, slope gradient, load intensity and erosion characteristics of slope material.

Foundation and floor slabs for buildings located on expansive soils shall be designed in accordance with Section 1808.6 of the Florida Building Code, Building.

Exception: Slab-on-ground and other foundation systems which have performed adequately in soil conditions similar to those encountered at the building site are permitted subject to the approval of the building official.

Soils meeting all four of the following provisions shall be considered expansive, except that tests to show compliance with Items 1, 2 and 3 shall not be required if the test prescribed in Item 4 is conducted:

  1. Plasticity Index (PI) of 15 or greater, determined in accordance with ASTM D4318.
  2. More than 10 percent of the soil particles pass a No. 200 sieve (75 µm), determined in accordance with ASTM D422.
  3. More than 10 percent of the soil particles are less than 5 micrometers in size, determined in accordance with ASTM D422.
  4. Expansion Index greater than 20, determined in accordance with ASTM D4829.
Footings for wood foundations shall be in accordance with Figures R403.1(2) and R403.1(3). Gravel shall be washed and well graded. The maximum size stone shall not exceed 3/4 inch (19.1 mm). Gravel shall be free from organic, clayey or silty soils. Sand shall be coarse, not smaller than 1/16-inch (1.6 mm) grains and shall be free from organic, clayey or silty soils. Crushed stone shall have a maximum size of 1/2 inch (12.7 mm).

For buildings where the monthly mean temperature of the building is maintained at a minimum of 64°F (18°C), footings are not required to extend below the frost line when protected from frost by insulation in accordance with Figure R403.3(1) and Table R403.3(1). Foundations protected from frost in accordance with Figure R403.3(1) and Table R403.3(1) shall not be used for unheated spaces such as porches, utility rooms, garages and carports, and shall not be attached to basements or crawl spaces that are not maintained at a minimum monthly mean temperature of 64°F (18°C).

Materials used below grade for the purpose of insulating footings against frost shall be labeled as complying with ASTM C578.

For SI: 1 inch = 25.4 mm.

  1. See Table R403.3(1) for required dimensions and R-values for vertical and horizontal insulation and minimum footing depth.

FIGURE R403.3(1)

INSULATION PLACEMENT FOR FROST-PROTECTED FOOTINGS IN HEATED BUILDINGS

TABLE R403.3(1)

MINIMUM FOOTING DEPTH AND INSULATION REQUIREMENTS FOR FROST-PROTECTED FOOTINGS IN HEATED BUILDINGSa

AIR FREEZING
INDEX
(°F-days)b
MINIMUM FOOTING
DEPTH, D
(inches)
VERTICAL
INSULATION
R-VALUEc, d
HORIZONTAL INSULATION
R-VALUEc, e
HORIZONTAL INSULATION DIMENSIONS
PER FIGURE R403.3(1) (inches)
Along walls At corners A B C
1,500 or less 12 4.5 Not required Not required Not required Not required Not required
2,000 14 5.6 Not required Not required Not required Not required Not required
2,500 16 6.7 1.7 4.9 12 24 40
3,000 16 7.8 6.5 8.6 12 24 40
3,500 16 9.0 8.0 11.2 24 30 60
4,000 16 10.1 10.5 13.1 24 36 60

For SI: 1 inch = 25.4 mm, °C = [(°F) - 32]/1.8.

  1. Insulation requirements are for protection against frost damage in heated buildings. Greater values may be required to meet energy conservation standards.
  2. See Figure R403.3(2) or Table R403.3(2) for Air Freezing Index values.
  3. Insulation materials shall provide the stated minimum R-values under long-term exposure to moist, below-ground conditions in freezing climates. The following R-values shall be used to determine insulation thicknesses required for this application: Type II expanded polystyrene-2.4R per inch; Type IV extruded polystyrene-4.5R per inch; Type VI extruded polystyrene-4.5R per inch; Type IX expanded polystyrene-3.2R per inch; Type X extruded polystyrene-4.5R per inch.
  4. Vertical insulation shall be expanded polystyrene insulation or extruded polystyrene insulation.
  5. Horizontal insulation shall be expanded polystyrene insulation or extruded polystyrene insulation.

For SI: °C = [(°F) -32]/1.8.

Note: The air-freezing index is defined as cumulative degree days below 32°F. It is used as a measure of the combined magnitude and duration of air temperature below freezing. The index was computed over a 12-month period (July-June) for each of the 3,044 stations used in the above analysis. Dates from the 1951-80 period were fitted to a Weibull probability distribution to produce an estimate of the 100-year return period.

FIGURE R403.3(2)

AIR-FREEZING INDEX AN ESTIMATE OF THE 100-YEAR RETURN PERIOD

TABLE R403.3(2)

AIR-FREEZING INDEX FOR U.S. LOCATIONS BY COUNTY

STATE AIR-FREEZING INDEX
1500 or less 2000 2500 3000 3500 4000
Alabama All counties
Alaska Ketchikan
Gateway,
Prince of Wales-
Outer Ketchikan
(CA), Sitka,
Wrangell-
Petersburg (CA)
Aleutians West (CA),
Haines, Juneau,
Skagway-Hoonah-
Angoon (CA), Yakutat
All counties
not listed
Arizona All counties
Arkansas All counties
California All counties
not listed
Nevada, Sierra
Colorado All counties
not listed
Archuleta, Custer,
Fremont, Huerfano,
Las Animas, Ouray,
Pitkin, San Miguel
Clear Creek, Conejos,
Costilla, Dolores, Eagle,
La Plata, Park, Routt,
San Juan, Summit
Alamosa, Grand,
Jackson, Larimer,
Moffat,
Rio Blanco,
Rio Grande
Chaffee, Gunnison,
Lake, Saguache
Hinsdale,
Mineral
Connecticut All counties
not listed
Hartford,
Litchfield
Delaware All counties
District of
Columbia
All counties
Florida All counties
Georgia All counties
Hawaii All counties
Idaho All counties
not listed
Adams, Bannock, Blaine,
Clearwater, Idaho,
Lincoln, Oneida, Power,
Valley, Washington
Bingham,
Bonneville, Camas,
Caribou, Elmore,
Franklin, Jefferson,
Madison, Teton
Bear Lake, Butte,
Custer, Fremont,
Lemhi
Clark
Illinois All counties
not listed
Boone, Bureau, Cook,
Dekalb, DuPage, Fulton,
Grundy, Henderson,
Henry, Iroquois,
Jo Daviess, Kane,
Kankakee, Kendall,
Knox, La Salle, Lake,
Lee, Livingston,
Marshall, Mason,
McHenry, McLean,
Mercer, Peoria, Putnam,
Rock Island,
Stark, Tazewell, Warren,
Whiteside, Will,
Woodford
Carroll, Ogle,
Stephenson,
Winnebago
Indiana All counties
not listed
Allen, Benton, Cass,
Fountain, Fulton,
Howard, Jasper,
Kosciusko, La Porte,
Lake, Marshall, Miami,
Newton, Porter, Pulaski,
Starke, Steuben, Tippecanoe,
Tipton, Wabash,
Warren, White
Iowa Appanoose,
Davis,
Fremont, Lee,
Van Buren
All counties
not listed
Allamakee, Black
Hawk, Boone, Bremer,
Buchanan, Buena Vista,
Butler, Calhoun,
Cerro Gordo, Cherokee,
Chickasaw, Clay,
Clayton, Delaware,
Dubuque, Fayette,
Floyd, Franklin,
Grundy, Hamilton,
Hancock, Hardin,
Humboldt, Ida,
Jackson, Jasper, Jones,
Linn, Marshall,
Palo Alto, Plymouth,
Pocahontas, Poweshiek,
Sac, Sioux, Story,
Tama, Webster,
Winnebago, Woodbury,
Worth, Wright
Dickinson,
Emmet, Howard,
Kossuth, Lyon,
Mitchell,
O'Brien, Osceola,
Winneshiek
Kansas All counties
Kentucky All counties
Louisiana All counties
Maine York Knox, Lincoln,
Sagadahoc
Androscoggin,
Cumberland, Hancock,
Kennebec, Waldo,
Washington
Aroostook,
Franklin, Oxford,
Penobscot,
Piscataquis,
Somerset
Maryland All counties
Massachusetts All counties
not listed
Berkshire, Franklin,
Hampden,
Worcester
Michigan Berrien,
Branch, Cass,
Kalamazoo,
Macomb, Ottawa,
St. Clair,
St. Joseph
All counties
not listed
Alger, Charlevoix,
Cheboygan, Chippewa,
Crawford, Delta,
Emmet, Iosco,
Kalkaska, Lake, Luce,
Mackinac, Menominee,
Missaukee,
Montmorency,
Ogemaw, Osceola,
Otsego, Roscommon,
Schoolcraft, Wexford
Baraga,
Dickinson, Iron,
Keweenaw,
Marquette
Gogebic,
Houghton,
Ontonagon
Minnesota Houston, Winona All counties
not listed
Aitkin,
Big Stone,
Carlton,
Crow Wing,
Douglas, Itasca,
Kanabec, Lake,
Morrison, Pine,
Pope, Stearns,
Stevens, Swift,
Todd, Wadena
Becker,
Beltrami, Cass,
Clay, Clearwater,
Grant, Hubbard,
Kittson,
Koochiching,
Lake of the Woods,
Mahnomen,
Marshall, Norman,
Otter Tail,
Pennington, Polk,
Red Lake, Roseau,
St. Louis, Traverse,
Wilkin
Mississippi All counties
Missouri All counties
not listed
Atchison, Mercer,
Nodaway, Putnam
Montana Mineral Broadwater,
Golden Valley,
Granite, Lake,
Lincoln,
Missoula,
Ravalli, Sanders,
Sweet Grass
Big Horn, Carbon,
Jefferson,
Judith Basin,
Lewis and Clark,
Meagher,
Musselshell,
Powder River,
Powell, Silver Bow,
Stillwater,
Westland
Carter, Cascade,
Deer Lodge,
Falcon, Fergus,
Flathead, Gallanting,
Glacier, Madison,
Park, Petroleum,
Ponder, Rosebud,
Teton, Treasure,
Yellowstone
Beaverhead,
Blaine,
Chouteau, Custer,
Dawson, Garfield,
Liberty, McCone,
Prairie, Toole,
Wibaux
Daniels, Hill,
Phillips, Richland,
Roosevelt,
Sheridan, Valley
Nebraska Adams, Banner,
Chase, Cheyenne,
Clay, Deuel, Dundy,
Fillmore, Franklin,
Frontier, Furnas,
Gage, Garden,
Gosper, Harlan,
Hayes, Hitchcock,
Jefferson, Kimball,
Morrill, Nemaha,
Nuckolls, Pawnee,
Perkins, Phelps,
Red Willow,
Richardson, Saline,
Scotts Bluff, Seward,
Thayer, Webster
All counties
not listed
Boyd, Burt, Cedar,
Cuming, Dakota,
Dixon, Dodge,
Knox, Thurston
Nevada All counties
not listed
Elko, Eureka,
Nye, Washoe,
White Pine
New
Hampshire
All counties
not listed
Carroll, Coos,
Grafton
New Jersey All counties
New Mexico All counties
not listed
Rio Arriba Colfax, Mora, Taos
New York Albany, Bronx,
Cayuga, Columbia,
Cortland, Dutchess,
Genessee, Kings,
Livingston, Monroe,
Nassau, New York,
Niagara, Onondaga,
Ontario, Orange,
Orleans, Putnam,
Queens, Richmond,
Rockland, Seneca,
Suffolk, Wayne,
Westchester, Yates
All counties
not listed
Clinton, Essex,
Franklin, Hamilton,
Herkimer,
Jefferson, Lewis,
St. Lawrence,
Warren
North
Carolina
All counties
North
Dakota
Billings,
Bowman
Adams, Dickey,
Golden Valley,
Hettinger, LaMoure,
Oliver, Ransom,
Sargent, Sioux,
Slope, Stark
All counties
not listed
Ohio All counties not
listed
Ashland, Crawford,
Defiance, Holmes,
Huron, Knox,
Licking, Morrow,
Paulding, Putnam,
Richland, Seneca,
Williams
Oklahoma All counties
Oregon All counties
not listed
Baker, Crook, Grant,
Harney
Pennsylvania All counties
not listed
Berks, Blair,
Bradford, Cambria,
Cameron, Centre,
Clarion, Clearfield,
Clinton, Crawford,
Elk, Forest,
Huntingdon,
Indiana, Jefferson,
Lackawanna,
Lycoming, McKean,
Pike, Potter,
Susquehanna, Tioga,
Venango, Warren,
Wayne, Wyoming
Rhode Island All counties
South
Carolina
All counties
South Dakota Bennett, Custer,
Fall River,
Lawrence, Mellette,
Shannon, Todd,
Tripp
Bon Homme,
Charles Mix,
Davison, Douglas,
Gregory, Jackson,
Jones, Lyman
All counties
not listed
Beadle, Brookings,
Brown, Campbell,
Codington, Corson,
Day, Deuel,
Edmunds, Faulk,
Grant, Hamlin,
Kingsbury,
Marshall,
McPherson,
Perkins, Roberts,
Spink, Walworth
Tennessee All counties
Texas All counties
Utah All counties
not listed
Box Elder,
Morgan, Weber
Garfield, Salt Lake,
Summit
Carbon, Daggett,
Duchesne, Rich,
Sanpete, Uintah,
Wasatch
Vermont Bennington,
Grand Isle,
Rutland, Windham
Addison,
Chittenden,
Franklin, Orange,
Washington,
Windsor
Caledonia, Essex,
Lamoille, Orleans
Virginia All counties
Washington All counties
not listed
Chelan, Douglas,
Ferry, Okanogan
West
Virginia
All counties
Wisconsin Kenosha,
Kewaunee, Racine,
Sheboygan,
Walworth
All counties
not listed
Ashland, Barron,
Burnett, Chippewa,
Clark, Dunn,
Eau Claire,
Florence, Forest,
Iron, Jackson,
La Crosse,
Langlade,
Marathon, Monroe,
Pepin, Polk,
Portage, Price, Rust,
St. Croix, Taylor,
Trempealeau,
Vilas, Wood
Bayfield, Douglas,
Lincoln, Oneida,
Sawyer, Washburn
Wyoming Goshen, Platte Converse, Crook,
Laramie, Niobrara
Campbell, Carbon,
Hot Springs,
Johnson, Natrona,
Sheridan, Uinta,
Weston
Albany, Big Horn,
Park, Washakie
Fremont, Teton Lincoln,
Sublette,
Sweetwater

For SI: 1 inch = 25.4 mm.

  1. See Table R403.3(1) for required dimensions and R-values for vertical and horizontal insulation.

FIGURE R403.3(3)

INSULATION PLACEMENT FOR FROST-PROTECTED FOOTINGS ADJACENT TO UNHEATED SLAB-ON-GROUND STRUCTURE

FIGURE R403.3(4)

INSULATION PLACEMENT FOR FROST-PROTECTED FOOTINGS ADJACENT TO HEATED STRUCTURE

Foundations that adjoin frost-protected shallow foundations shall be protected from frost in accordance with Section R403.1.4.
Vertical wall insulation and horizontal insulation of frost-protected shallow foundations that adjoin a slab-on-ground foundation that does not have a monthly mean temperature maintained at a minimum of 64°F (18°C) shall be in accordance with Figure R403.3(3) and Table R403.3(1). Vertical wall insulation shall extend between the frost-protected shallow foundation and the adjoining slab foundation. Required horizontal insulation shall be continuous under the adjoining slab foundation and through any foundation walls adjoining the frost- protected shallow foundation. Where insulation passes through a foundation wall, it shall be either of a type complying with this section and having bearing capacity equal to or greater than the structural loads imposed by the building, or the building shall be designed and constructed using beams, lintels, cantilevers or other means of transferring building loads such that the structural loads of the building do not bear on the insulation.

Where a frost-protected shallow foundation abuts a structure that has a monthly mean temperature maintained at a minimum of 64°F (18°C), horizontal insulation and vertical wall insulation shall not be required between the frost-protected shallow foundation and the adjoining structure. Where the frost-protected shallow foundation abuts the heated structure, the horizontal insulation and vertical wall insulation shall extend along the adjoining foundation in accordance with Figure R403.3(4) a distance of not less than Dimension A in Table R403.3(1).

Exception: Where the frost-protected shallow foundation abuts the heated structure to form an inside corner, vertical insulation extending along the adjoining foundation is not required.

Horizontal insulation placed less than 12 inches (305 mm) below the ground surface or that portion of horizontal insulation extending outward more than 24 inches (610 mm) from the foundation edge shall be protected against damage by use of a concrete slab or asphalt paving on the ground surface directly above the insulation or by cementitious board, plywood rated for below-ground use, or other approved materials placed below ground, directly above the top surface of the insulation.
Final grade shall be sloped in accordance with Section R401.3. In other than Group I Soils, as detailed in Table R405.1, gravel or crushed stone beneath horizontal insulation below ground shall drain to daylight or into an approved sewer system.
The use of foam plastic in areas of "very heavy" termite infestation probability shall be in accordance with Section R318.4.

Footings for precast concrete foundations shall comply with Section R403.4.

TABLE R403.4

MINIMUM DEPTH OF CRUSHED STONE FOOTINGSa (D), (inches)

NUMBER
OF
STORIES
UNIFORM
WALL
LOAD
LOAD-BEARING VALUE OF SOIL (psf)
1500 2000 3000 4000
MH, CH, CL, ML SC, GC, SM, GM, SP, SW GP, GW
Wall width (inches) Wall width (inches) Wall width (inches) Wall width (inches)
6 8 10 12 6 8 10 12 6 8 10 12 6 8 10 12
Conventional light-frame construction
1-story 1100 plf 6 4 4 4 6 4 4 4 6 4 4 4 6 4 4 4
2-story 1800 plf 8 6 4 4 6 4 4 4 6 4 4 4 6 4 4 4
3-story 2900 plf 16 14 12 10 10 8 6 6 6 4 4 4 6 4 4 4
4-inch brick veneer over light-frame or 8-inch hollow concrete masonry
1-story 1500 plf 6 4 4 4 6 4 4 4 6 4 4 4 6 4 4 4
2-story 2700 plf 14 12 10 8 10 8 6 4 6 4 4 4 6 4 4 4
3-story 4000 plf 22 22 20 18 16 14 12 10 10 8 6 4 6 4 4 4
8-inch solid or fully grouted masonry
1-story 2000 plf 10 8 6 4 6 4 4 4 6 4 4 4 6 4 4 4
2-story 3600 plf 20 18 16 16 14 12 10 8 8 6 4 4 6 4 4 4
3-story 5300 plf 32 30 28 26 22 22 20 18 14 12 10 8 10 8 6 4

For SI: 1 inch = 25.4 mm, 1 plf = 14.6 N/m, 1 pound per square foot = 47.9 N/m2.

  1. Linear interpolation of stone depth between wall widths is permitted within each Load-Bearing Value of Soil (psf).

FIGURE R403.4(1)

BASEMENT OR CRAWL SPACE WITH PRECAST FOUNDATION WALL BEARING ON CRUSHED STONE

FIGURE R403.4(2)

BASEMENT OR CRAWL SPACE WITH PRECAST FOUNDATION WALL ON SPREAD FOOTING

Clean crushed stone shall be free from organic, clayey or silty soils. Crushed stone shall be angular in nature and meet ASTM C33, with the maximum size stone not to exceed 1/2 inch (12.7 mm) and the minimum stone size not to be smaller than 1/16 inch (1.6 mm). Crushed stone footings for precast foundations shall be installed in accordance with Figure R403.4(1) and Table R403.4. Crushed stone footings shall be consolidated using a vibratory plate in a maximum of 8-inch (203 mm) lifts. Crushed stone footings shall be limited to Seismic Design Categories A, B and C.
Concrete footings shall be installed in accordance with Section R403.1 and Figure R403.4(2).
Concrete foundation walls shall be selected and constructed in accordance with the provisions of Section R404.1.3. Masonry foundation walls shall be selected and constructed in accordance with the provisions of Section R404.1.2.

Concrete or masonry foundation walls shall be designed in accordance with accepted engineering practice where either of the following conditions exists:

  1. Walls are subject to hydrostatic pressure from ground water.
  2. Walls supporting more than 48 inches (1219 mm) of unbalanced backfill that do not have permanent lateral support at the top or bottom.

TABLE R404.1.1(1)

PLAIN MASONRY FOUNDATION WALLSf

MAXIMUM WALL HEIGHT
(feet)
MAXIMUM
UNBALANCED
BACKFILL HEIGHTc
(feet)
PLAIN MASONRYa MINIMUM NOMINAL WALL THICKNESS (inches)
Soil classesb
GW, GP, SW
and SP
GM, GC, SM,
SM-SC and ML
SC, MH, ML-CL
and inorganic CL
5 4 6 solidd or 8 6 solidd or 8 6 solidd or 8
5 6 solidd or 8 8 10
6 4 6 solidd or 8 6 solidd or 8 6 solidd or 8
5 6 solidd or 8 8 10
6 8 10 12
7 4 6 solidd or 8 8 8
5 6 solidd or 8 10 10
6 10 12 10 solidd
7 12 10 solidd 12 solidd
8 4 6 solidd or 8 6 solidd or 8 8
5 6 solidd or 8 10 12
6 10 12 12 solidd
7 12 12 solidd Footnote e
8 10 groutd 12 groutd Footnote e
9 4 6 groutd or 8 solidd or 12 6 groutd or 8 solidd 8 groutd or 10 solidd
5 6 groutd or 10 solidd 8 groutd or 12 solidd 8 groutd
6 8 groutd or 12 solidd 10 groutd 10 groutd
7 10 groutd 10 groutd 12 grout
8 10 groutd 12 grout Footnote e
9 12 grout Footnote e Footnote e

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 Pa.

  1. Mortar shall be Type M or S and masonry shall be laid in running bond. Ungrouted hollow masonry units are permitted except where otherwise indicated.
  2. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  3. Unbalanced backfill height is the difference in height between the exterior finish ground level and the lower of the top of the concrete footing that supports the foundation wall or the interior finish ground level. Where an interior concrete slab-on-grade is provided and is in contact with the interior surface of the foundation wall, measurement of the unbalanced backfill height from the exterior finish ground level to the top of the interior concrete slab is permitted.
  4. Solid indicates solid masonry unit; grout indicates grouted hollow units.
  5. Wall construction shall be in accordance with either Table R404.1.1(2), Table R404.1.1(3), Table R404.1.1(4), or a design shall be provided.
  6. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.1(2)

8-INCH MASONRY FOUNDATION WALLS WITH REINFORCING WHERE d ≥ 5 INCHESa, c, f

WALL HEIGHT HEIGHT OF
UNBALANCED
BACKFILLe
MINIMUM VERTICAL REINFORCEMENT AND SPACING (INCHES)b, c
Soil classes and lateral soil loadd (psf per foot below grade)
GW, GP, SW and SP soils
30
GM, GC, SM, SM-SC and ML soils
45
SC, ML-CL and inorganic CL soils
60
6 feet 8 inches 4 feet (or less) #4 at 48 #4 at 48 #4 at 48
5 feet #4 at 48 #4 at 48 #4 at 48
6 feet 8 inches #4 at 48 #5 at 48 #6 at 48
7 feet 4 inches 4 feet (or less) #4 at 48 #4 at 48 #4 at 48
5 feet #4 at 48 #4 at 48 #4 at 48
6 feet #4 at 48 #5 at 48 #5 at 48
7 feet 4 inches #5 at 48 #6 at 48 #6 at 40
8 feet 4 feet (or less) #4 at 48 #4 at 48 #4 at 48
5 feet #4 at 48 #4 at 48 #4 at 48
6 feet #4 at 48 #5 at 48 #5 at 48
7 feet #5 at 48 #6 at 48 #6 at 40
8 feet #5 at 48 #6 at 48 #6 at 32
8 feet 8 inches 4 feet (or less) #4 at 48 #4 at 48 #4 at 48
5 feet #4 at 48 #4 at 48 #5 at 48
6 feet #4 at 48 #5 at 48 #6 at 48
7 feet #5 at 48 #6 at 48 #6 at 40
8 feet 8 inches #6 at 48 #6 at 32 #6 at 24
9 feet 4 inches 4 feet (or less) #4 at 48 #4 at 48 #4 at 48
5 feet #4 at 48 #4 at 48 #5 at 48
6 feet #4 at 48 #5 at 48 #6 at 48
7 feet #5 at 48 #6 at 48 #6 at 40
8 feet #6 at 48 #6 at 40 #6 at 24
9 feet 4 inches #6 at 40 #6 at 24 #6 at 16
10 feet 4 feet (or less) #4 at 48 #4 at 48 #4 at 48
5 feet #4 at 48 #4 at 48 #5 at 48
6 feet #4 at 48 #5 at 48 #6 at 48
7 feet #5 at 48 #6 at 48 #6 at 32
8 feet #6 at 48 #6 at 32 #6 at 24
9 feet #6 at 40 #6 at 24 #6 at 16
10 feet #6 at 32 #6 at 16 #6 at 16

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157 kPa/mm.

  1. Mortar shall be Type M or S and masonry shall be laid in running bond.
  2. Alternative reinforcing bar sizes and spacings having an equivalent cross-sectional area of reinforcement per lineal foot of wall shall be permitted provided the spacing of the reinforcement does not exceed 72 inches in Seismic Design Categories A, B and C, and 48 inches in Seismic Design Categories D0, D1 and D2.
  3. Vertical reinforcement shall be Grade 60 minimum. The distance, d, from the face of the soil side of the wall to the center of vertical reinforcement shall be not less than 5 inches.
  4. Soil classes are in accordance with the Unified Soil Classification System and design lateral soil loads are for moist conditions without hydrostatic pressure. Refer to Table R405.1.
  5. Unbalanced backfill height is the difference in height between the exterior finish ground level and the lower of the top of the concrete footing that supports the foundation wall or the interior finish ground level. Where an interior concrete slab-on-grade is provided and is in contact with the interior surface of the foundation wall, measurement of the unbalanced backfill height from the exterior finish ground level to the top of the interior concrete slab is permitted.
  6. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.1(3)

10-INCH MASONRY FOUNDATION WALLS WITH REINFORCING WHERE d ≥ 6.75 INCHESa, c, f

WALL HEIGHT HEIGHT OF
UNBALANCED
BACKFILLe
MINIMUM VERTICAL REINFORCEMENT AND SPACING (INCHES)b, c
Soil classes and later soil loadd (psf per foot below grade)
GW, GP, SW and SP soils
30
GM, GC, SM, SM-SC and ML soils
45
SC, ML-CL and inorganic CL soils
60
6 feet 8 inches 4 feet (or less) #4 at 56 #4 at 56 #4 at 56
5 feet #4 at 56 #4 at 56 #4 at 56
6 feet 8 inches #4 at 56 #5 at 56 #5 at 56
7 feet 4 inches 4 feet (or less) #4 at 56 #4 at 56 #4 at 56
5 feet #4 at 56 #4 at 56 #4 at 56
6 feet #4 at 56 #4 at 56 #5 at 56
7 feet 4 inches #4 at 56 #5 at 56 #6 at 56
8 feet 4 feet (or less) #4 at 56 #4 at 56 #4 at 56
5 feet #4 at 56 #4 at 56 #4 at 56
6 feet #4 at 56 #4 at 56 #5 at 56
7 feet #4 at 56 #5 at 56 #6 at 56
8 feet #5 at 56 #6 at 56 #6 at 48
8 feet 8 inches 4 feet (or less) #4 at 56 #4 at 56 #4 at 56
5 feet #4 at 56 #4 at 56 #4 at 56
6 feet #4 at 56 #4 at 56 #5 at 56
7 feet #4 at 56 #5 at 56 #6 at 56
8 feet 8 inches #5 at 56 #6 at 48 #6 at 32
9 feet 4 inches 4 feet (or less) #4 at 56 #4 at 56 #4 at 56
5 feet #4 at 56 #4 at 56 #4 at 56
6 feet #4 at 56 #5 at 56 #5 at 56
7 feet #4 at 56 #5 at 56 #6 at 56
8 feet #5 at 56 #6 at 56 #6 at 40
9 feet 4 inches #6 at 56 #6 at 40 #6 at 24
10 feet 4 feet (or less) #4 at 56 #4 at 56 #4 at 56
5 feet #4 at 56 #4 at 56 #4 at 56
6 feet #4 at 56 #5 at 56 #5 at 56
7 feet #5 at 56 #6 at 56 #6 at 48
8 feet #5 at 56 #6 at 48 #6 at 40
9 feet #6 at 56 #6 at 40 #6 at 24
10 feet #6 at 48 #6 at 32 #6 at 24

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157 kPa/mm.

  1. Mortar shall be Type M or S and masonry shall be laid in running bond.
  2. Alternative reinforcing bar sizes and spacings having an equivalent cross-sectional area of reinforcement per lineal foot of wall shall be permitted provided the spacing of the reinforcement does not exceed 72 inches in Seismic Design Categories A, B and C, and 48 inches in Seismic Design Categories D0, D1 and D2.
  3. Vertical reinforcement shall be Grade 60 minimum. The distance, d, from the face of the soil side of the wall to the center of vertical reinforcement shall be not less than 6.75 inches.
  4. Soil classes are in accordance with the Unified Soil Classification System and design lateral soil loads are for moist conditions without hydrostatic pressure. Refer to Table R405.1.
  5. Unbalanced backfill height is the difference in height between the exterior finish ground level and the lower of the top of the concrete footing that supports the foundation wall or the interior finish ground level. Where an interior concrete slab-on-grade is provided and is in contact with the interior surface of the foundation wall, measurement of the unbalanced backfill height from the exterior finish ground level to the top of the interior concrete slab is permitted.
  6. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.1(4)

12-INCH MASONRY FOUNDATION WALLS WITH REINFORCING WHERE d ≥ 8.75 INCHESa, c, f

WALL HEIGHT HEIGHT OF
UNBALANCED
BACKFILLe
MINIMUM VERTICAL REINFORCEMENT AND SPACING (INCHES)b, c
Soil classes and lateral soil loadd (psf per foot below grade)
GW, GP, SW and SP soils
30
GM, GC, SM, SM-SC and ML soils
45
SC, ML-CL and inorganic CL soils
60
6 feet 8 inches 4 feet (or less) #4 at 72 #4 at 72 #4 at 72
5 feet #4 at 72 #4 at 72 #4 at 72
6 feet 8 inches #4 at 72 #4 at 72 #5 at 72
7 feet 4 inches 4 feet (or less) #4 at 72 #4 at 72 #4 at 72
5 feet #4 at 72 #4 at 72 #4 at 72
6 feet #4 at 72 #4 at 72 #5 at 72
7 feet 4 inches #4 at 72 #5 at 72 #6 at 72
8 feet 4 feet (or less) #4 at 72 #4 at 72 #4 at 72
5 feet #4 at 72 #4 at 72 #4 at 72
6 feet #4 at 72 #4 at 72 #5 at 72
7 feet #4 at 72 #5 at 72 #6 at 72
8 feet #5 at 72 #6 at 72 #6 at 64
8 feet 8 inches 4 feet (or less) #4 at 72 #4 at 72 #4 at 72
5 feet #4 at 72 #4 at 72 #4 at 72
6 feet #4 at 72 #4 at 72 #5 at 72
7 feet #4 at 72 #5 at 72 #6 at 72
8 feet 8 inches #5 at 72 #7 at 72 #6 at 48
9 feet 4 inches 4 feet (or less) #4 at 72 #4 at 72 #4 at 72
5 feet #4 at 72 #4 at 72 #4 at 72
6 feet #4 at 72 #5 at 72 #5 at 72
7 feet #4 at 72 #5 at 72 #6 at 72
8 feet #5 at 72 #6 at 72 #6 at 56
9 feet 4 inches #6 at 72 #6 at 48 #6 at 40
10 feet 4 feet (or less) #4 at 72 #4 at 72 #4 at 72
5 feet #4 at 72 #4 at 72 #4 at 72
6 feet #4 at 72 #5 at 72 #5 at 72
7 feet #4 at 72 #6 at 72 #6 at 72
8 feet #5 at 72 #6 at 72 #6 at 48
9 feet #6 at 72 #6 at 56 #6 at 40
10 feet #6 at 64 #6 at 40 #6 at 32

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157 kPa/mm.

  1. Mortar shall be Type M or S and masonry shall be laid in running bond.
  2. Alternative reinforcing bar sizes and spacings having an equivalent cross-sectional area of reinforcement per lineal foot of wall shall be permitted provided the spacing of the reinforcement does not exceed 72 inches in Seismic Design Categories A, B and C, and 48 inches in Seismic Design Categories D0, D1 and D2.
  3. Vertical reinforcement shall be Grade 60 minimum. The distance, d, from the face of the soil side of the wall to the center of vertical reinforcement shall be not less than 8.75 inches.
  4. Soil classes are in accordance with the Unified Soil Classification System and design lateral soil loads are for moist conditions without hydrostatic pressure. Refer to Table R405.1.
  5. Unbalanced backfill height is the difference in height between the exterior finish ground level and the lower of the top of the concrete footing that supports the foundation wall or the interior finish ground levels. Where an interior concrete slab-on-grade is provided and in contact with the interior surface of the foundation wall, measurement of the unbalanced backfill height is permitted to be measured from the exterior finish ground level to the top of the interior concrete slab is permitted.
  6. The use of this table shall be prohibited for soil classifications not shown.

Masonry foundation walls shall be designed and constructed in accordance with the provisions of this section or in accordance with the provisions of TMS 402/ACI 530/ASCE 5. When TMS 402/ACI 530/ASCE 5 or the provisions of this section are used to design masonry foundation walls, project drawings, typical details and specifications are not required to bear the seal of the architect or engineer responsible for design, unless otherwise required by the state law of the jurisdiction having authority.

TABLE R404.1.2(1)

MINIMUM HORIZONTAL REINFORCEMENT FOR CONCRETE BASEMENT WALLSa, b

MAXIMUM UNSUPPORTED
HEIGHT OF BASEMENT WALL
(feet)
LOCATION OF HORIZONTAL REINFORCEMENT
≤ 8 One No. 4 bar within 12 inches of the top of the wall story and one No. 4 bar near mid-height of the wall story.
> 8 One No. 4 bar within 12 inches of the top of the wall story and one No. 4 bar near third points in the wall story.

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa.

  1. Horizontal reinforcement requirements are for reinforcing bars with a minimum yield strength of 40,000 psi and concrete with a minimum concrete compressive strength of 2,500 psi.
  2. See Section R404.1.3.2 for minimum reinforcement required for foundation walls supporting above-grade concrete walls.

TABLE R404.1.2(2)

MINIMUM VERTICAL REINFORCEMENT FOR 6-INCH NOMINAL FLAT CONCRETE BASEMENT WALLSb, c, d, e, g, h, i, j, k

MAXIMUM UNSUPPORTED
WALL HEIGHT
(feet)
MAXIMUM UNBALANCED
BACKFILL HEIGHTf
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
8 4 NR NR NR
5 NR 6 @ 39 6 @ 48
6 5 @ 39 6 @ 48 6 @ 35
7 6 @ 48 6 @ 34 6 @ 25
8 6 @ 39 6 @ 25 6 @ 18
9 4 NR NR NR
5 NR 5 @ 37 6 @ 48
6 5 @ 36 6 @ 44 6 @ 32
7 6 @ 47 6 @ 30 6 @ 22
8 6 @ 34 6 @ 22 6 @ 16
9 6 @ 27 6 @ 17 DR
10 4 NR NR NR
5 NR 5 @ 35 6 @ 48
6 6 @ 48 6 @ 41 6 @ 30
7 6 @ 43 6 @ 28 6 @ 20
8 6 @ 31 6 @ 20 DR
9 6 @ 24 6 @ 15 DR
10 6 @ 19 DR DR

For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.

NR = Not required.

  1. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  2. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi concrete with a minimum specified compressive strength of 2,500 psi and vertical reinforcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  3. Vertical reinforcement with a yield strength of less than 60,000 psi and/or bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.2(9).
  4. Deflection criterion is L/240, where L is the height of the basement wall in inches.
  5. Interpolation is not permitted.
  6. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  7. NR indicates no vertical wall reinforcement is required, except for 6-inch-nominal walls formed with stay-in-place forming systems in which case vertical reinforcement shall be No. 4@48 inches on center.
  8. See Section R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  9. See Table R608.3 for tolerance from nominal thickness permitted for flat walls.
  10. DR means design is required in accordance with the applicable building code, or where there is no code, in accordance with ACI 318.
  11. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.2(3)

MINIMUM VERTICAL REINFORCEMENT FOR 8-INCH (203 mm) NOMINAL FLAT CONCRETE BASEMENT WALLSb, c, d, e, f, h, i, j

MAXIMUM UNSUPPORTED
WALL HEIGHT
(feet)
MAXIMUM UNBALANCED
BACKFILL HEIGHTg
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
8 4 NR NR NR
5 NR NR NR
6 NR NR 6 @ 37
7 NR 6 @ 36 6 @ 35
8 6 @ 41 6 @ 35 6 @ 26
9 4 NR NR NR
5 NR NR NR
6 NR NR 6 @ 35
7 NR 6 @ 35 6 @ 32
8 6 @ 36 6 @ 32 6 @ 23
9 6 @ 35 6 @ 25 6 @ 18
10 4 NR NR NR
5 NR NR NR
6 NR NR 6 @ 35
7 NR 6 @ 35 6 @ 29
8 6 @ 35 6 @ 29 6 @ 21
9 6 @ 34 6 @ 22 6 @ 16
10 6 @ 27 6 @ 17 6 @ 13

For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.

NR = Not required.

  1. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  2. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi, concrete with a minimum specified compressive strength of 2,500 psi and vertical reinforcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  3. Vertical reinforcement with a yield strength of less than 60,000 psi and/or bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.2(9).
  4. NR indicates no vertical reinforcement is required.
  5. Deflection criterion is L/240, where L is the height of the basement wall in inches.
  6. Interpolation is not permitted.
  7. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  8. See Section R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  9. See Table R608.3 for tolerance from nominal thickness permitted for flat walls.
  10. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.2(4)

MINIMUM VERTICAL REINFORCEMENT FOR 10-INCH NOMINAL FLAT CONCRETE BASEMENT WALLSb, c, d, e, f, h, i, j

MAXIMUM UNSUPPORTED
WALL HEIGHT
(feet)
MAXIMUM UNBALANCED
BACKFILL HEIGHTg
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
8 4 NR NR NR
5 NR NR NR
6 NR NR NR
7 NR NR NR
8 6 @ 48 6 @ 35 6 @ 28
9 4 NR NR NR
5 NR NR NR
6 NR NR NR
7 NR NR 6 @ 31
8 NR 6 @ 31 6 @ 28
9 6 @ 37 6 @ 28 6 @ 24
10 4 NR NR NR
5 NR NR NR
6 NR NR NR
7 NR NR 6 @ 28
8 NR 6 @ 28 6 @ 28
9 6 @ 33 6 @ 28 6 @ 21
10 6 @ 28 6 @ 23 6 @ 17

For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.

NR = Not required.

  1. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  2. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi concrete with a minimum specified compressive strength of 2,500 psi and vertical reinforcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  3. Vertical reinforcement with a yield strength of less than 60,000 psi and/or bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.2(9).
  4. NR indicates no vertical reinforcement is required.
  5. Deflection criterion is L/240, where L is the height of the basement wall in inches.
  6. Interpolation is not permitted.
  7. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  8. See Section R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  9. See Table R608.3 for tolerance from nominal thickness permitted for flat walls.
  10. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.2(5)

MINIMUM VERTICAL WALL REINFORCEMENT FOR 6-INCH WAFFLE-GRID BASEMENT WALLSb, c, d, e, g, h, i, j

MAXIMUM UNSUPPORTED
WALL HEIGHT
(feet)
MAXIMUM UNBALANCED
BACKFILL HEIGHTf
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
8 4 4 @ 48 4 @ 46 6 @ 39
5 4 @ 45 5 @ 46 6 @ 47
6 5 @ 45 6 @ 40 DR
7 6 @ 44 DR DR
8 6 @ 32 DR DR
9 4 4 @ 48 4 @ 46 4 @ 37
5 4 @ 42 5 @ 43 6 @ 44
6 5 @ 41 6 @ 37 DR
7 6 @ 39 DR DR
> 8 DRi DR DR
10 4 4 @ 48 4 @ 46 4 @ 35
5 4 @ 40 5 @ 40 6 @ 41
6 5 @ 38 6 @ 34 DR
7 6 @ 36 DR DR
> 8 DR DR DR

For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.

  1. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  2. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi concrete with a minimum specified compressive strength of 2,500 psi and vertical reinforcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  3. Maximum spacings shown are the values calculated for the specified bar size. Where the bar used is Grade 60 and the size specified in the table, the actual spacing in the wall shall not exceed a whole-number multiple of 12 inches (i.e., 12, 24, 36 and 48) that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield strength of less than 60,000 psi and/or bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.2(9).
  4. Deflection criterion is L/240, where L is the height of the basement wall in inches.
  5. Interpolation is not permitted.
  6. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  7. See Section R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  8. See Table R608.3 for thicknesses and dimensions of waffle-grid walls.
  9. DR means design is required in accordance with the applicable building code, or where there is no code, in accordance with ACI 318.
  10. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.2(6)

MINIMUM VERTICAL REINFORCEMENT FOR 8-INCH WAFFLE-GRID BASEMENT WALLSb, c, d, e, f, h, i, j, k

MAXIMUM UNSUPPORTED
WALL HEIGHT
(feet)
MAXIMUM UNBALANCED
BACKFILL HEIGHTg
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
8 4 NR NR NR
5 NR 5 @ 48 5 @ 46
6 5 @ 48 5 @ 43 6 @ 45
7 5 @ 46 6 @ 43 6 @ 31
8 6 @ 48 6 @ 32 6 @ 23
9 4 NR NR NR
5 NR 5 @ 47 5 @ 46
6 5 @ 46 5 @ 39 6 @ 41
7 5 @ 42 6 @ 38 6 @ 28
8 6 @ 44 6 @ 28 6 @ 20
9 6 @ 34 6 @ 21 DR
10 4 NR NR NR
5 NR 5 @ 46 5 @ 44
6 5 @ 46 5 @ 37 6 @ 38
7 5 @ 38 6 @ 35 6 @ 25
8 6 @ 39 6 @ 25 DR
9 6 @ 30 DR DR
10 6 @ 24 DR DR

For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.

NR = Not required.

  1. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  2. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi concrete with a minimum specified compressive strength of 2,500 psi and vertical reinforcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  3. Maximum spacings shown are the values calculated for the specified bar size. Where the bar used is Grade 60 (420 MPa) and the size specified in the table, the actual spacing in the wall shall not exceed a whole-number multiple of 12 inches (i.e., 12, 24, 36 and 48) that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield strength of less than 60,000 psi and/or bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.2(9).
  4. NR indicates no vertical reinforcement is required.
  5. Deflection criterion is L/240, where L is the height of the basement wall in inches.
  6. Interpolation shall not be permitted.
  7. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  8. See Section R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  9. See Table R608.3 for thicknesses and dimensions of waffle-grid walls.
  10. DR means design is required in accordance with the applicable building code, or where there is no code, in accordance with ACI 318.
  11. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.2(7)

MINIMUM VERTICAL REINFORCEMENT FOR 6-INCH (152 mm) SCREEN-GRID BASEMENT WALLSb, c, d, e, g, h, i, j

MAXIMUM UNSUPPORTED
WALL HEIGHT
(feet)
MAXIMUM UNBALANCED
BACKFILL HEIGHTf
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
8 4 4 @ 48 4 @ 48 5 @ 43
5 4 @ 48 5 @ 48 5 @ 37
6 5 @ 48 6 @ 45 6 @ 32
7 6 @ 48 DR DR
8 6 @ 36 DR DR
9 4 4 @ 48 4 @ 48 4 @ 41
5 4 @ 48 5 @ 48 6 @ 48
6 5 @ 45 6 @ 41 DR
7 6 @ 43 DR DR
> 8 DR DR DR
10 4 4 @ 48 4 @ 48 4 @ 39
5 4 @ 44 5 @ 44 6 @ 46
6 5 @ 42 6 @ 38 DR
7 6 @ 40 DR DR
> 8 DR DR DR

For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.

  1. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R405.1.
  2. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi, concrete with a minimum specified compressive strength of 2,500 psi and vertical reinforcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  3. Maximum spacings shown are the values calculated for the specified bar size. Where the bar used is Grade 60 and the size specified in the table, the actual spacing in the wall shall not exceed a whole-number multiple of 12 inches (i.e., 12, 24, 36 and 48) that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield strength of less than 60,000 psi and/or bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.2(9).
  4. Deflection criterion is L/240, where L is the height of the basement wall in inches.
  5. Interpolation is not permitted.
  6. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  7. See Sections R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  8. See Table R608.3 for thicknesses and dimensions of screen-grid walls.
  9. DR means design is required in accordance with the applicable building code, or where there is no code, in accordance with ACI 318.
  10. The use of this table shall be prohibited for soil classifications not shown.

TABLE R404.1.2(8)

MINIMUM VERTICAL REINFORCEMENT FOR 6-, 8-, 10- AND 12-INCH NOMINAL FLAT BASEMENT WALLSb, c, d, e, f, h, i, k, n, o

MAXIMUM
WALL
HEIGHT
(feet)
MAXIMUM
UNBALANCED
BACKFILL
HEIGHTg
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)
Soil classesa and design lateral soil (psf per foot of depth)
GW, GP, SW, SP
30
GM, GC, SM, SM-SC and ML
45
SC, ML-CL and inorganic CL
60
Minimum nominal wall thickness (inches)
6 8 10 12 6 8 10 12 6 8 10 12
5 4 NR NR NR NR NR NR NR NR NR NR NR NR
5 NR NR NR NR NR NR NR NR NR NR NR NR
6 4 NR NR NR NR NR NR NR NR NR NR NR NR
5 NR NR NR NR NR NRl NR NR 4 @ 35 NRl NR NR
6 NR NR NR NR 5 @ 48 NR NR NR 5 @ 36 NR NR NR
7 4 NR NR NR NR NR NR NR NR NR NR NR NR
5 NR NR NR NR NR NR NR NR 5 @ 47 NR NR NR
6 NR NR NR NR 5 @ 42 NR NR NR 6 @ 43 5 @ 48 NRl NR
7 5 @ 46 NR NR NR 6 @ 42 5 @ 46 NRl NR 6 @ 34 6 @ 48 NR NR
8 4 NR NR NR NR NR NR NR NR NR NR NR NR
5 NR NR NR NR 4 @ 38 NRl NR NR 5 @ 43 NR NR NR
6 4 @ 37 NRl NR NR 5 @ 37 NR NR NR 6 @ 37 5 @ 43 NRl NR
7 5 @ 40 NR NR NR 6 @ 37 5 @ 41 NRl NR 6 @ 34 6 @ 43 NR NR
8 6 @ 43 5 @ 47 NRl NR 6 @ 34 6 @ 43 NR NR 6 @ 27 6 @ 32 6 @ 44 NR
9 4 NR NR NR NR NR NR NR NR NR NR NR NR
5 NR NR NR NR 4 @ 35 NRl NR NR 5 @ 40 NR NR NR
6 4 @ 34 NRl NR NR 6 @ 48 NR NR NR 6 @ 36 6 @ 39 NRl NR
7 5 @ 36 NR NR NR 6 @ 34 5 @ 37 NR NR 6 @ 33 6 @ 38 5 @ 37 NRl
8 6 @ 38 5 @ 41 NRl NR 6 @ 33 6 @ 38 5 @ 37 NRl 6 @ 24 6 @ 29 6 @ 39 4 @ 48m
9 6 @ 34 6 @ 46 NR NR 6 @ 26 6 @ 30 6 @ 41 NR 6 @ 19