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 walls and partitions for buildings.

Exception: Buildings and structures located within the High-Velocity Hurricane Zone shall comply with the provisions of Chapter 44.

Wall construction shall be capable of accommodating all loads imposed in accordance with Section R301 and of transmitting the resulting loads to the supporting structural elements.
Compressible floor-covering materials that compress more than 1/32 inch (0.8 mm) when subjected to 50 pounds (23 kg) applied over 1 inch square (645 mm) of material and are greater than 1/8 inch (3.2 mm) in thickness in the uncompressed state shall not extend beneath walls, partitions or columns, which are fastened to the floor.
Wood and wood-based products used for load-supporting purposes shall conform to the applicable provisions of this section.
Sawn lumber shall be identified by a grade mark of an accredited lumber grading or inspection agency and have design values certified by an accreditation body that complies with DOC PS 20. In lieu of a grade mark, a certification of inspection issued by a lumber grading or inspection agency meeting the requirements of this section shall be accepted.
Approved end-jointed lumber identified by a grade mark conforming to Section R602.1 shall be permitted to be used interchangeably with solid-sawn members of the same species and grade. End-jointed lumber used in an assembly required elsewhere in this code to have a fire-resistance rating shall have the designation "Heat Resistant Adhesive" or "HRA" included in its grade mark.
Glued-laminated timbers shall be manufactured and identified as required in ANSI A190.1, ANSI 117 and ASTM D3737.
Structural log members shall comply with the provisions of ICC 400.
Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D5456.
Cross-laminated timber shall be manufactured and identified as required by ANSI/APA PRG 320.
Engineered wood rim boards shall conform to ANSI/APA PRR 410 or shall be evaluated in accordance with ASTM D7672. Structural capacities shall be in accordance with either ANSI/APA PRR 410 or established in accordance with ASTM D7672. Rim boards conforming to ANSI/APA PRR 410 shall be marked in accordance with that standard.
Wood structural panel sheathing shall conform to DOC PS 1, DOC PS 2 or, when manufactured in Canada, CSA O437 or CSA O325. Panels shall be identified for grade, bond classification, and performance category by a grade mark or certificate of inspection issued by an approved agency.
Particleboard shall conform to ANSI A208.1. Particleboard shall be identified by the grade mark or certificate of inspection issued by an approved agency.
Fiberboard shall conform to ASTM C208. Fiberboard sheathing, where used structurally, shall be identified by an approved agency as conforming to ASTM C208.
Structural insulated panels shall be manufactured and identified in accordance with ANSI/APA PRS 610.1.

Studs shall be a minimum No. 3, standard or stud grade lumber.

Exception: Bearing studs not supporting floors and nonbearing studs shall be permitted to be utility grade lumber, provided the studs are spaced in accordance with Section R602.3.

Exterior walls of woodframe construction shall be designed in accordance with Section R301.2.1.1 or ANSI AWC NDS.

Table R602.3(1) Fastening Schedule.

Reserved.

Figure R602.3(1) Typical Wall, Floor and Roof Framing.

Reserved.

Table R602.3(2) Alternate Attachments to Table R602.3(1).

Reserved.

Figure R602.3(2) Framing Details.

Reserved.

Table R602.3(3) Requirements for Wood Structural Panel Wall Sheathing Used to Resist Wind Pressures.

Reserved.

Table R602.3(4) Allowable Spans for Particleboard Wall Sheathing.

Reserved.

Table R602.3(5) Size, Height and Spacing of Wood Studs.

Reserved.

Reserved.

Table R602.3.2 Single Top-Plate Splice Connection Details.

Reserved.

Reserved.

Figure R602.6(1) Notching and Bored Hole Limitations for Exterior Walls and Bearing Walls.

Reserved.

Figure R602.6(2) Notching and Bored Hole Limitations for Interior Nonbearing Walls.

Reserved.

Reserved.

Figure R602.6.1 Top Plate Framing to Accommodate Piping.

Reserved.

Reserved.

Table R602.7(1) Girder Spans and Header Spans for Exterior Bearing Walls.

Reserved.

Table R602.7(2) Girder Spans and Header Spans for Interior Bearing Walls.

Reserved.

Table R602.7(3) Girder and Header Spans for Open Porches.

Reserved.

Reserved.

Figure R602.7.1(1) Single Member Header in Exterior Bearing Wall.

Reserved.

Figure R602.7.1(2) Alternative Single Member Header Without Cripple.

Reserved.

Reserved.

Figure R602.7.2 Rim Board Header Construction.

Reserved.

Reserved.

Table R602.7.3 Maximum Spans for Wood Structural Panel Box Headers.

Reserved.

Figure R602.7.3 Typical Wood Structural Panel Box Header Construction.

Reserved.

Reserved.

Table R602.7.5 Minimum Number of Full Height Studs at Each End of Headers in Exterior Walls.

Reserved.

R602.10 Wall Bracing

ILLUSTRATION
Reserved.

Reserved.

Figure R602.10.1.1 Braced Wall Lines.

Reserved.

Reserved.

Table R602.10.1.3 Braced Wall Line Spacing.

Reserved.

Reserved.

Table R602.10.3(1) Bracing Requirements Based on Wind Speed.

Reserved.

Table R602.10.3(2) Wind Adjustment Factors to the Required Length of Wall Bracing.

Reserved.

Table R602.10.3(3) Bracing Requirements Based on Seismic Design Category.

Reserved.

Table R602.10.3(4) Seismic Adjustment Factors to the Required Length of Wall Bracing.

Reserved.

Reserved.

Table R602.10.5 Minimum Length of Braced Wall Panels.

Reserved.

Figure R602.10.5 Braced Wall Panels with Continuous Sheathing.

Reserved.

Reserved.

Table R602.10.5.2 Partial Credit for Braced Wall Panels Less Than 48 Inches in Actual Length.

Reserved.

Reserved.

Table R602.10.6.1 Minimum Hold-Down Forces for Method ABW Braced Wall Panels.

Reserved.

Figure R602.10.6.1 Method ABW—Alternate Braced Wall Panel.

Reserved.

Reserved.

Figure R602.10.6.2 Method PFH—Portal Frame with Hold-Downs.

Reserved.

Reserved.

Figure R602.10.6.4 Method CS-PF—Continuously Sheathed Portal Frame Panel Construction.

Reserved.

Table R602.10.6.4 Tension Strap Capacity for Resisting Wind Pressures Perpendicular to Methods PFH, PFG and CS-PF Braced Wall Panels.

Reserved.

Reserved.

Table R602.10.6.5 Method BV-WSP Wall Bracing Requirements.

Reserved.

Figure R602.10.6.5 Method BV-WSP—Wall Bracing for Dwellings with Stone and Masonry Veneer in Seismic Design Categories D0, D1 and D2.

Reserved.

Reserved.

Figure R602.10.7 End Conditions for Braced Wall Lines with Continuous Sheathing.

Reserved.

Reserved.

Figure R602.10.8(1) Braced Wall Panel Connection When Perpendicular to Floor/Ceiling Framing.

Reserved.

Figure R602.10.8(2) Braced Wall Panel Connection When Parallel to Floor/Ceiling Framing.

Reserved.

Reserved.

Figure R602.10.8.2(1) Braced Wall Panel Connection to Perpendicular Rafters.

Reserved.

Figure R602.10.8.2(2) Braced Wall Panel Connection Option to Perpendicular Rafters or Roof Trusses.

Reserved.

Figure R602.10.8.2(3) Braced Wall Panel Connection Option to Perpendicular Rafters or Roof Trusses.

Reserved.

Reserved.

Figure R602.12.1 Rectangle Circumscribing an Enclosed Building.

Reserved.

Reserved.

Table R602.12.4 Minimum Number of Bracing Units on Each Side of the Circumscribed Rectangle.

Reserved.

Reserved.

Figure R602.12.5 Bracing Unit Distribution.

Reserved.

In accordance with Section R301.2.1.1, the design of cold-formed steel wall framing shall be in accordance with AISI S230, Standard for Cold-Formed Steel Framing—Prescriptive Method For One- and Two-Family Dwellings.
Wood structural panels shall conform to DOC PS 1, DOC PS 2 or ANSI/APA PRP 210, CSA O437 or CSA O325. Panels shall be identified by a grade mark or certificate of inspection issued by an approved agency.
The maximum allowable spans for wood structural panel wall sheathing shall not exceed the values set forth in Section R602.3.
Wood structural panel wall sheathing shall be attached to framing in accordance with Section R602.3.
Particleboard shall conform to ANSI A208.1 and shall be so identified by a grade mark or certificate of inspection issued by an approved agency.
Masonry construction shall be designed and constructed in accordance with the provisions of this section and Section R301.2.1.1, TMS 402, TMS 403 or TMS 404.
When the empirical design provisions of Appendix A of TMS 402, the provisions of TMS 403, or the provisions of this section are used to design masonry, 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.
Concrete masonry units shall conform to the following standards: ASTM C55 for concrete brick; ASTM C73 for calcium silicate face brick; ASTM C90 for load-bearing concrete masonry units; ASTM C744 for prefaced concrete and calcium silicate masonry units; or ASTM C1634 for concrete facing brick.

Clay or shale masonry units shall conform to the following standards: ASTM C34 for structural clay load-bearing wall tile; ASTM C56 for structural clay nonload-bearing wall tile; ASTM C62 for building brick (solid masonry units made from clay or shale); ASTM C1088 for solid units of thin veneer brick; ASTM C126 for ceramic-glazed structural clay facing tile, facing brick and solid masonry units; ASTM C212 for structural clay facing tile; ASTM C216 for facing brick (solid masonry units made from clay or shale); ASTM C652 for hollow brick (hollow masonry units made from clay or shale); or ASTM C1405 for glazed brick (single-fired solid brick units).

Exception: Structural clay tile for nonstructural use in fireproofing of structural members and in wall furring shall not be required to meet the compressive strength specifications. The fire-resistance rating shall be determined in accordance with ASTM E119 or UL 263 and shall comply with the requirements of Section R302.

AAC masonry units shall conform to ASTM C1691 and ASTM C1693 for the strength class specified.
Stone masonry units shall conform to the following standards: ASTM C503 for marble building stone (exterior); ASTM C568 for limestone building stone; ASTM C615 for granite building stone; ASTM C616 for sandstone building stone; or ASTM C629 for slate building stone.
Architectural cast stone shall conform to ASTM C1364.
Adhered manufactured stone masonry veneer units shall conform to ASTM C1670.
Second hand masonry units shall not be reused unless they conform to the requirements of new units. The units shall be of whole, sound materials and free from cracks and other defects that will interfere with proper laying or use. Old mortar shall be cleaned from the unit before reuse.

Except for mortars listed in Sections R606.2.9, R606.2.10 and R606.2.11, mortar for use in masonry construction shall meet the proportion specifications of Table R606.2.8 or the property specifications of ASTM C270. The type of mortar shall be in accordance with Sections R606.2.8.1, R606.2.8.2 and R606.2.8.3.

TABLE R606.2.8

MORTAR PROPORTIONSa, b

PROPORTIONS BY VOLUME (cementitious materials)
MORTAR TYPE Portland cement or
blended cement
Mortar cement Masonry cement Hydrated limec or
lime putty
Aggregate ratio
(measured in damp,
loose conditions)
M S N M S N
Cement-lime M 1 1/4 Not less than 21/4 and
not more than 3 times
the sum of separate
volumes of lime, if
used, and cement
S 1 over 1/4 to 1/2
N 1 over 1/2 to 11/4
O 1 over 11/4 to 21/2
Mortar cement M 1 1
M 1
S 1/2 1
S 1
N 1
O 1
Masonry cement M 1 1
M 1
S 1/2 1
S 1
N 1
O 1

For SI: 1 cubic foot = 0.0283 m3, 1 pound = 0.454 kg.

  1. For the purpose of these specifications, the weight of 1 cubic foot of the respective materials shall be considered to be as follows:

    Portland Cement94 poundsMasonry CementWeight printed on bag
    Mortar CementWeight printed on bagHydrated Lime40 pounds
    Lime Putty (Quicklime)80 poundsSand, damp and loose80 pounds of dry sand
  2. Two air-entraining materials shall not be combined in mortar.
  3. Hydrated lime conforming to the requirements of ASTM C207.
Mortar for masonry foundation walls constructed as set forth in Tables R404.1.1(1) through R404.1.1(4) shall be Type M or S mortar.
Mortar for masonry serving as the lateral force-resisting system in Seismic Design Categories A, B and C shall be Type M, S or N mortar.
Mortar for masonry serving as the lateral-force-resisting system in Seismic Design Categories D0, D1 and D2 shall be Type M or S Portland cement-lime or mortar cement mortar.
Surface-bonding mortar shall comply with ASTM C887. Surface bonding of concrete masonry units shall comply with ASTM C946.
Thin-bed mortar for AAC masonry shall comply with Article 2.1 C.1 of TMS 602. Mortar used for the leveling courses of AAC masonry shall comply with Article 2.1 C.2 of TMS 602.
Mortar for use with adhered masonry veneer shall conform to ASTM C270 Type S or Type N or shall comply with ANSI A118.4 for latex-modified portland cement mortar.

Grout shall consist of cementitious material and aggregate in accordance with ASTM C476 or the proportion specifications of Table R606.2.12. Type M or Type S mortar to which sufficient water has been added to produce pouring consistency shall be permitted to be used as grout.

TABLE R606.2.12

GROUT PROPORTIONS BY VOLUME FOR MASONRY CONSTRUCTION

TYPE PORTLAND CEMENT
OR BLENDED CEMENT
SLAG CEMENT
HYDRATED LIME
OR LIME PUTTY
AGGREGATE MEASURED IN A DAMP, LOOSE CONDITION
Fine Coarse
Fine 1 0 to 1/10
21/4 to 3 times the sum of the volume of
the cementitious materials
Coarse 1 0 to 1/10
21/4 to 3 times the sum of the volume of
the cementitious materials
1 to 2 times the sum of the volumes
of the cementitious materials
Metal reinforcement and accessories shall conform to Article 2.4 of TMS 602. Where provided in exterior walls, joint reinforcement shall be a minimum No. 9-gauge ladder-type stainless steel, hot dipped galvanized, or epoxy coated in accordance with TMS 602 Section 2.4E1, 2.4F1b or 2.4F2a as appropriate.

Unless otherwise required or indicated on the project drawings, head and bed joints shall be 3/8 inch (9.5 mm) thick, except that the thickness of the bed joint of the starting course placed over foundations shall be not less than 1/4 inch (6.4 mm) and not more than 3/4 inch (19.1 mm). Mortar joint thickness for load-bearing masonry shall be within the following tolerances from the specified dimensions:

  1. Bed joint: + 1/8 inch (3.2 mm).
  2. Head joint: - 1/4 inch (6.4 mm), + 3/8 inch (9.5 mm).
  3. Collar joints: - 1/4 inch (6.4 mm), + 3/8 inch (9.5 mm).
Masonry rough openings may vary in the cross section dimension or elevation dimension specified on the approved plans from - 1/4 inch (6.4 mm) to + 1/2 inch (12.7 mm). For exterior window and door installation provisions, see Section R609.3.
The mortar shall be sufficiently plastic and units shall be placed with sufficient pressure to extrude mortar from the joint and produce a tight joint. Deep furrowing of bed joints that produces voids shall not be permitted. Any units disturbed to the extent that initial bond is broken after initial placement shall be removed and relaid in fresh mortar. Surfaces to be in contact with mortar shall be clean and free of deleterious materials.
Solid masonry units shall be laid with full head and bed joints and all interior vertical joints that are designed to receive mortar shall be filled.
For hollow masonry units, head and bed joints shall be filled solidly with mortar for a distance in from the face of the unit not less than the thickness of the face shell.

The installation of wall ties shall be as follows:

  1. The ends of wall ties shall be embedded in mortar joints. Wall ties shall have not less than 5/8-inch (15.9 mm) mortar coverage from the exposed face.
  2. Wall ties shall not be bent after being embedded in grout or mortar.
  3. For solid masonry units, solid grouted hollow units, or hollow units in anchored masonry veneer, wall ties shall be embedded in mortar bed not less than 11/2 inches (38 mm).
  4. For hollow masonry units in other than anchored masonry veneer, wall ties shall engage outer face shells by not less than 1/2 inch (13 mm).
Bars shall be completely embedded in mortar or grout. Joint reinforcement embedded in horizontal mortar joints shall not have less than 5/8-inch (15.9 mm) mortar coverage from the exposed face. Other reinforcement shall have a minimum coverage of one bar diameter over all bars, but not less than 3/4 inch (19 mm), except where exposed to weather or soil, in which case the minimum coverage shall be 2 inches (51 mm).

Minimum corrosion protection of joint reinforcement, anchor ties and wire fabric for use in masonry wall construction shall conform to Table R606.3.4.1.

TABLE R606.3.4.1

MINIMUM CORROSION PROTECTION

MASONRY METAL
ACCESSORY
STANDARD
Joint reinforcement, interior walls ASTM A641, Class 1
Wire ties or anchors in exterior walls
completely embedded in mortar or grout
ASTM A641, Class 3
Wire ties or anchors in exterior walls not
completely embedded in mortar or grout
ASTM A153, Class B-2
Joint reinforcement in exterior walls or
interior walls exposed to moist environment
ASTM A153, Class B-2
Sheet metal ties or anchors exposed to
weather
ASTM A153, Class B-2
Sheet metal ties or anchors completely
embedded in mortar or grout
ASTM A653, Coating
Designation G60
Stainless steel hardware for any exposure ASTM A167, Type 304

Grout shall be a plastic mix suitable for pumping without segregation of the constituents and shall be mixed thoroughly. Grout shall be placed by pumping or by an approved alternate method and shall be placed before any initial set occurs and not more than 11/2 hours after water has been added. Grout shall be consolidated by puddling or mechanical vibrating during placing and reconsolidated after excess moisture has been absorbed but before plasticity is lost. Grout shall not be pumped through aluminum pipes.

Maximum pour heights and the minimum dimensions of spaces provided for grout placement shall conform to Table R606.3.5.1. Grout shall be poured in lifts of 8-foot (2438 mm) maximum height. Where a total grout pour exceeds 8 feet (2438 mm) in height, the grout shall be placed in lifts not exceeding 64 inches (1626 mm) and special inspection during grouting shall be required. If the work is stopped for 1 hour or longer, the horizontal construction joints shall be formed by stopping all tiers at the same elevation and with the grout 1 inch (25 mm) below the top.

TABLE R606.3.5.1

GROUT SPACE DIMENSIONS AND POUR HEIGHTS

GROUT TYPE GROUT POUR MAXIMUM HEIGHT
(feet)
MINIMUM WIDTH OF
GROUT SPACESa, b
(inches)
MINIMUM GROUTb, c SPACE DIMENSIONS FOR
GROUTING CELLS OF HOLLOW UNITS
(inches × inches)
Fine 1 0.75 1.5 × 2
5 2 2 × 3
12 2.5 2.5 × 3
24 3 3 × 3
Coarse 1 1.5 1.5 × 3
5 2 2.5 × 3
12 2.5 3 × 3
24 3 3 × 4

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

  1. For grouting between masonry wythes.
  2. Grout space dimension is the clear dimension between any masonry protrusion and shall be increased by the horizontal projection of the diameters of the horizontal bars within the cross section of the grout space.
  3. Area of vertical reinforcement shall not exceed 6 percent of the area of the grout space.
Provisions shall be made for cleaning the space to be grouted. Mortar that projects more than 1/2 inch (12.7 mm) into the grout space and any other foreign matter shall be removed from the grout space prior to inspection and grouting. Where required by the building official, cleanouts shall be provided in the bottom course of masonry for each grout pour where the grout pour height exceeds 64 inches (1626 mm). In solid grouted masonry, cleanouts shall be spaced horizontally not more than 32 inches (813 mm) on center. The cleanouts shall be sealed before grouting and after inspection.

Requirements for grouted masonry construction shall be as follows:

  1. Masonry shall be built to preserve the unobstructed vertical continuity of the cells or spaces to be filled. In partially grouted construction, cross webs forming cells to be filled shall be full-bedded in mortar to prevent leakage of grout. Head and end joints shall be solidly filled with mortar for a distance in from the face of the wall or unit not less than the thickness of the longitudinal face shells.
  2. Vertical reinforcement shall be held in position at top and bottom and at intervals not exceeding 200 diameters of the reinforcement.
  3. Cells containing reinforcement shall be filled solidly with grout.
  4. The thickness of grout or mortar between masonry units and reinforcement shall be not less than 1/4 inch (6.4 mm), except that 1/4-inch (6.4 mm) bars shall be permitted to be laid in horizontal mortar joints not less than 1/2 inch (12.7 mm) thick, and steel wire reinforcement shall be permitted to be laid in horizontal mortar joints not less than twice the thickness of the wire diameter.
Grouted multiple-wythe masonry shall conform to all the requirements specified in Section R606.3.5 and the requirements of this section.
Where all interior vertical spaces are filled with grout in multiple-wythe construction, masonry headers shall not be permitted. Metal wall ties shall be used in accordance with Section R606.13.2 to prevent spreading of the wythes and to maintain the vertical alignment of the wall. Wall ties shall be installed in accordance with Section R606.13.2 where the backup wythe in multiple-wythe construction is fully grouted.
Vertical grout barriers or dams shall be built of solid masonry across the grout space the entire height of the wall to control the flow of the grout horizontally. Grout barriers shall be not more than 25 feet (7620 mm) apart. The grouting of any section of a wall between control barriers shall be completed in one day without interruptions greater than 1 hour.
Masonry laid in running and stack bond shall conform to Sections R606.3.7.1 and R606.3.7.2.
In each wythe of masonry laid in running bond, head joints in successive courses shall be offset by not less than one-fourth the unit length, or the masonry walls shall be reinforced longitudinally as required in Section R606.3.7.2.
Where unit masonry is laid with less head joint offset than in Section R606.3.7.1, the minimum area of horizontal reinforcement placed in mortar bed joints or in bond beams spaced not more than 48 inches (1219 mm) apart shall be 0.0007 times the vertical cross-sectional area of the wall.
The nominal thickness of masonry walls shall conform to the requirements of Sections R606.4.1 through R606.4.4.
The minimum thickness of masonry bearing walls more than one story high shall be 8 inches (203 mm). Solid masonry walls of one-story dwellings and garages shall be not less than 6 inches (152 mm) in thickness where not greater than 9 feet (2743 mm) in height, provided that where gable construction is used, an additional 6 feet (1829 mm) is permitted to the peak of the gable. Masonry walls shall be laterally supported in either the horizontal or vertical direction at intervals as required by Section R606.6.4.
The minimum thickness of rough, random or coursed rubble stone masonry walls shall be 16 inches (406 mm).
Where walls of masonry of hollow units or masonry-bonded hollow walls are decreased in thickness, a course of solid masonry or masonry units filled with mortar or grout shall be constructed between the wall below and the thinner wall above, or special units or construction shall be used to transmit the loads from face shells or wythes above to those below.
Unreinforced solid masonry parapet walls shall be not less than 8 inches (203 mm) thick and their height shall not exceed four times their thickness. Unreinforced hollow unit masonry parapet walls shall be not less than 8 inches (203 mm) thick, and their height shall not exceed three times their thickness. Masonry parapet walls in areas subject to wind loads of 30 pounds per square foot (1.44 kPa) located in Seismic Design Category D0, D1 or D2, or on townhouses in Seismic Design Category C shall be reinforced in accordance with Section R606.1.
Corbeled masonry shall be in accordance with Sections R606.5.1 through R606.5.3.
Solid masonry units or masonry units filled with mortar or grout shall be used for corbeling.

The maximum projection of one unit shall not exceed one-half the height of the unit or one-third the thickness at right angles to the wall. The maximum corbeled projection beyond the face of the wall shall not exceed:

  1. One-half of the wall thickness for multiwythe walls bonded by mortar or grout and wall ties or masonry headers.
  2. One-half the wythe thickness for single wythe walls, masonry-bonded hollow walls, multiwythe walls with open collar joints and veneer walls.
Where corbeled masonry is used to support floor or roof-framing members, the top course of the corbel shall be a header course or the top course bed joint shall have ties to the vertical wall.
Bearing and support conditions shall be in accordance with Sections R606.6.1 through R606.6.4.
Each masonry wythe shall be supported by at least two-thirds of the wythe thickness.
Cavity wall or masonry veneer construction shall be permitted to be supported on an 8-inch (203 mm) foundation wall, provided the 8-inch (203 mm) wall is corbeled to the width of the wall system above with masonry constructed of solid masonry units or masonry units filled with mortar or grout. The total horizontal projection of the corbel shall not exceed 2 inches (51 mm) with individual corbels projecting not more than one-third the thickness of the unit or one-half the height of the unit. The hollow space behind the corbeled masonry shall be filled with mortar or grout.
Beams, girders or other concentrated loads supported by a wall or column shall have a bearing of not less than 3 inches (76 mm) in length measured parallel to the beam upon solid masonry not less than 4 inches (102 mm) in thickness, or upon a metal bearing plate of adequate design and dimensions to distribute the load safely, or upon a continuous reinforced masonry member projecting not less than 4 inches (102 mm) from the face of the wall.
Joists shall have a bearing of not less than 11/2 inches (38 mm), except as provided in Section R606.6.3, and shall be supported in accordance with Section R606.1.

Masonry walls shall be laterally supported in either the horizontal or the vertical direction in accordance with Section R301.2.1.1, TMS 402, TMS 403 or TMS 404.

Table R606.6.4 Spacing of Lateral Support for Masonry Walls.

Reserved.

The unsupported height of masonry piers shall not exceed 10 times their least dimension. Where structural clay tile or hollow concrete masonry units are used for isolated piers to support beams and girders, the cellular spaces shall be filled solidly with grout or Type M or S mortar, except that unfilled hollow piers shall be permitted to be used if their unsupported height is not more than four times their least dimension. Where hollow masonry units are solidly filled with grout or Type M, S or N mortar, the allowable compressive stress shall be permitted to be increased as provided in Table R606.9.
Hollow piers shall be capped with 4 inches (102 mm) of solid masonry or concrete, a masonry cap block, or shall have cavities of the top course filled with concrete or grout.
Chases and recesses in masonry walls shall not be deeper than one-third the wall thickness, and the maximum length of a horizontal chase or horizontal projection shall not exceed 4 feet (1219 mm), and shall have not less than 8 inches (203 mm) of masonry in back of the chases and recesses and between adjacent chases or recesses and the jambs of openings. Chases and recesses in masonry walls shall be designed and constructed so as not to reduce the required strength or required fire resistance of the wall and in no case shall a chase or recess be permitted within the required area of a pier. Masonry directly above chases or recesses wider than 12 inches (305 mm) shall be supported on noncombustible lintels.

Allowable compressive stresses in masonry shall not exceed the values prescribed in Table R606.9. In determining the stresses in masonry, the effects of all loads and conditions of loading and the influence of all forces affecting the design and strength of the several parts shall be taken into account.

TABLE R606.9

ALLOWABLE COMPRESSIVE STRESSES FOR EMPIRICAL DESIGN OF MASONRY

CONSTRUCTION;
COMPRESSIVE STRENGTH
OF UNIT, GROSS AREA
ALLOWABLE COMPRESSIVE
STRESSESa GROSS
CROSS-SECTIONAL AREAb
Type M or S mortar Type N mortar
Solid masonry of brick and
other solid units of clay or
shale; sand-lime or
concrete brick:
8,000 + psi 350 300
4,500 psi 225 200
2,500 psi 160 140
1,500 psi 115 100
Groutedc masonry, of clay
or shale; sand-lime or
4,500 + psi 225 200
2,500 psi 160 140
1,500 psi 115 100
Solid masonry of solid
3,000 + psi 225 200
2,000 psi 160 140
1,200 psi 115 100
Masonry of hollow load-
bearing units:
2,000 + psi 140 120
1,500 psi 115 100
1,000 psi 75 70
700 psi 60 55
Hollow walls (cavity or
masonry bondedd) solid
units:
2,500 + psi 160 140
1,500 psi 115 100
Hollow units 75 70
Stone ashlar masonry:
Granite 720 640
Limestone or marble 450 400
Sandstone or cast stone 360 320
Rubble stone masonry:
Coarse, rough or random 120 100

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

  1. Linear interpolation shall be used for determining allowable stresses for masonry units having compressive strengths that are intermediate between those given in the table.
  2. Gross cross-sectional area shall be calculated on the actual rather than nominal dimensions.
  3. See Section R606.13.
  4. Where floor and roof loads are carried upon one wythe, the gross cross-sectional area is that of the wythe under load; if both wythes are loaded, the gross cross-sectional area is that of the wall minus the area of the cavity between the wythes. Walls bonded with metal ties shall be considered as cavity walls unless the collar joints are filled with mortar or grout.
In walls or other structural members composed of different kinds or grades of units, materials or mortars, the maximum stress shall not exceed the allowable stress for the weakest of the combination of units, materials and mortars of which the member is composed. The net thickness of any facing unit that is used to resist stress shall be not less than 11/2 inches (38 mm).
Masonry over openings shall be supported by steel lintels, reinforced concrete or masonry lintels or masonry arches, designed to support load imposed.

Reserved.

Figure R606.11(1) Anchorage Requirements for Masonry Walls Located in Seismic Design Category A, B or C and Where Wind Loads Are Less Than 30 PSF.

Reserved.

Figure R606.11(2) Requirements for Reinforced Grouted Masonry Construction in Seismic Design Category C.

Reserved.

Figure R606.11(3) Requirements for Reinforced Masonry Construction in Seismic Design Category D0, D1 or D2.

Reserved.

Reserved.

Reserved.

Table R606.12.3.2 Minimum Distributed Wall Reinforcement for Buildings Assigned to Seismic Design Category D0 or D1.

Reserved.

The facing and backing of multiple-wythe masonry walls shall be bonded in accordance with Section R606.13.1, R606.13.2 or R606.13.3. In cavity walls, neither the facing nor the backing shall be less than 3 inches (76 mm) nominal in thickness and the cavity shall be not more than 4 inches (102 mm) nominal in width. The backing shall be not less than as thick as the facing.

Exception: Cavities shall be permitted to exceed the 4-inch (102 mm) nominal dimension provided tie size and tie spacing have been established by calculation.

Bonding with solid or hollow masonry headers shall comply with Sections R606.13.1.1 and R606.13.1.2.
Where the facing and backing (adjacent wythes) of solid masonry construction are bonded by means of masonry headers, not less than 4 percent of the wall surface of each face shall be composed of headers extending not less than 3 inches (76 mm) into the backing. The distance between adjacent full-length headers shall not exceed 24 inches (610 mm) either vertically or horizontally. In walls in which a single header does not extend through the wall, headers from the opposite sides shall overlap not less than 3 inches (76 mm), or headers from opposite sides shall be covered with another header course overlapping the header below not less than 3 inches (76 mm).
Where two or more hollow units are used to make up the thickness of a wall, the stretcher courses shall be bonded at vertical intervals not exceeding 34 inches (864 mm) by lapping not less than 3 inches (76 mm) over the unit below, or by lapping at vertical intervals not exceeding 17 inches (432 mm) with units that are not less than 50 percent thicker than the units below.
Bonding with wall ties or joint reinforcement shall comply with Section R606.13.2.3.
Bonding with wall ties, except as required by Section R607, where the facing and backing (adjacent wythes) of masonry walls are bonded with 3/16-inch-diameter (5 mm) wall ties embedded in the horizontal mortar joints, there shall be not less than one metal tie for each 41/2 square feet (0.418 m2) of wall area. Ties in alternate courses shall be staggered. The maximum vertical distance between ties shall not exceed 24 inches (610 mm), and the maximum horizontal distance shall not exceed 36 inches (914 mm). Rods or ties bent to rectangular shape shall be used with hollow masonry units laid with the cells vertical. In other walls, the ends of ties shall be bent to 90-degree (0.79 rad) angles to provide hooks not less than 2 inches (51 mm) long. Additional bonding ties shall be provided at all openings, spaced not more than 3 feet (914 mm) apart around the perimeter and within 12 inches (305 mm) of the opening.
Where the facing and backing (adjacent wythes) of masonry are bonded with adjustable wall ties, there shall be not less than one tie for each 2.67 square feet (0.248 m2) of wall area. Neither the vertical nor the horizontal spacing of the adjustable wall ties shall exceed 24 inches (610 mm). The maximum vertical offset of bed joints from one wythe to the other shall be 1.25 inches (32 mm). The maximum clearance between connecting parts of the ties shall be 1/16 inch (2 mm). Where pintle legs are used, ties shall have not less than two 3/16-inch-diameter (5 mm) legs.
Where the facing and backing (adjacent wythes) of masonry are bonded with prefabricated joint reinforcement, there shall be not less than one cross wire serving as a tie for each 2.67 square feet (0.248 m2) of wall area. The vertical spacing of the joint reinforcement shall not exceed 16 inches (406 mm). Cross wires on prefabricated joint reinforcement shall not be smaller than No. 9 gage. The longitudinal wires shall be embedded in the mortar.
Bonding with natural and cast stone shall conform to Sections R606.13.3.1 and R606.13.3.2.
In ashlar masonry, bonder units, uniformly distributed, shall be provided to the extent of not less than 10 percent of the wall area. Such bonder units shall extend not less than 4 inches (102 mm) into the backing wall.
Rubble stone masonry 24 inches (610 mm) or less in thickness shall have bonder units with a maximum spacing of 3 feet (914 mm) vertically and 3 feet (914 mm) horizontally, and if the masonry is of greater thickness than 24 inches (610 mm), shall have one bonder unit for each 6 square feet (0.557 m2) of wall surface on both sides.
Anchored masonry veneer installed over a backing of wood or cold-formed steel shall meet the requirements of Section R703.8.
Adhered masonry veneer shall be installed in accordance with the requirements of Section R703.12.
Panels of glass unit masonry located in load-bearing and nonload-bearing exterior and interior walls shall be constructed in accordance with this section.
Hollow glass units shall be partially evacuated and have a minimum average glass face thickness of 3/16 inch (5 mm). The surface of units in contact with mortar shall be treated with a polyvinyl butyral coating or latex-based paint. The use of reclaimed units is prohibited.
Hollow or solid glass block units shall be standard or thin units.
The specified thickness of standard units shall be not less than 37/8 inches (98 mm).
The specified thickness of thin units shall be not less than 31/8 inches (79 mm) for hollow units and not less than 3 inches (76 mm) for solid units.
Isolated panels of glass unit masonry shall conform to the requirements of this section.

The maximum area of each individual standard-unit panel shall be 144 square feet (13.4 m2) where the design wind pressure is 20 pounds per square foot (958 Pa). The maximum area of such panels subjected to design wind pressures other than 20 pounds per square foot (958 Pa) shall be in accordance with Figure R607.4.1. The maximum panel dimension between structural supports shall be 25 feet (7620 mm) in width or 20 feet (6096 mm) in height.

For SI: 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kPa.

FIGURE R607.4.1

GLASS UNIT MASONRY DESIGN WIND LOAD RESISTANCE

The maximum area of each individual thin-unit panel shall be 85 square feet (7.9 m2). The maximum dimension between structural supports shall be 15 feet (4572 mm) in width or 10 feet (3048 mm) in height. Thin units shall not be used in applications where the design wind pressure as stated in Table R301.2(1) exceeds 20 pounds per square foot (958 Pa).
The maximum area of each individual standard-unit panel shall be 250 square feet (23.2 m2). The maximum area of each thin-unit panel shall be 150 square feet (13.9 m2). The maximum dimension between structural supports shall be 25 feet (7620 mm) in width or 20 feet (6096 mm) in height.
The width of curved panels shall conform to the requirements of Sections R607.4.1, R607.4.2 and R607.4.3, except additional structural supports shall be provided at locations where a curved section joins a straight section, and at inflection points in multicurved walls.
Glass unit masonry panels shall conform to the support requirements of this section.
The maximum total deflection of structural members that support glass unit masonry shall not exceed l/600.

Glass unit masonry panels shall be laterally supported along the top and sides of the panel. Lateral supports for glass unit masonry panels shall be designed to resist not less than 200 pounds per lineal feet (2918 N/m) of panel, or the actual applied loads, whichever is greater. Except for single unit panels, lateral support shall be provided by panel anchors along the top and sides spaced not greater than 16 inches (406 mm) on center or by channel-type restraints. Single unit panels shall be supported by channel-type restraints.

Exceptions:

  1. Lateral support is not required at the top of panels that are one unit wide.
  2. Lateral support is not required at the sides of panels that are one unit high.
Panel anchors shall be spaced not greater than 16 inches (406 mm) on center in both jambs and across the head. Panel anchors shall be embedded not less than 12 inches (305 mm) and shall be provided with two fasteners so as to resist the loads specified in Section R607.5.2.
Glass unit masonry panels shall be recessed not less than 1 inch (25 mm) within channels and chases. Channel-type restraints shall be oversized to accommodate expansion material in the opening, packing and sealant between the framing restraints, and the glass unit masonry perimeter units.
Before bedding of glass units, the sill area shall be covered with a water base asphaltic emulsion coating. The coating shall be not less than 1/8 inch (3 mm) thick.
Glass unit masonry panels shall be provided with expansion joints along the top and sides at all structural supports. Expansion joints shall be not less than 3/8 inch (10 mm) in thickness and shall have sufficient thickness to accommodate displacements of the supporting structure. Expansion joints shall be entirely free of mortar and other debris and shall be filled with resilient material.
Glass unit masonry shall be laid with Type S or N mortar. Mortar shall not be retempered after initial set. Mortar unused within 11/2 hours after initial mixing shall be discarded.
Glass unit masonry panels shall have horizontal joint reinforcement spaced not greater than 16 inches (406 mm) on center located in the mortar bed joint. Horizontal joint reinforcement shall extend the entire length of the panel but shall not extend across expansion joints. Longitudinal wires shall be lapped not less than 6 inches (152 mm) at splices. Joint reinforcement shall be placed in the bed joint immediately below and above openings in the panel. The reinforcement shall have not less than two parallel longitudinal wires of size W1.7 or greater, and have welded cross wires of size W1.7 or greater.
Glass units shall be placed so head and bed joints are filled solidly. Mortar shall not be furrowed. Head and bed joints of glass unit masonry shall be 1/4 inch (6.4 mm) thick, except that vertical joint thickness of radial panels shall be not less than 1/8 inch (3 mm) or greater than 5/8 inch (16 mm). The bed joint thickness tolerance shall be minus 1/16 inch (1.6 mm) and plus 1/8 inch (3 mm). The head joint thickness tolerance shall be plus or minus 1/8 inch (3 mm).
Exterior concrete walls shall be designed and constructed in accordance with the provisions of this section or in accordance with the provisions of PCA 100 or ACI 318. Where PCA 100, ACI 318 or the provisions of this section are used to design concrete 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.

These provisions are based on the assumption that interior walls and partitions, both load-bearing and nonload-bearing, floors and roof/ceiling assemblies are constructed of light-framed construction complying with the limitations of this code and the additional limitations of Section R608.2. Design and construction of light-framed assemblies shall be in accordance with the applicable provisions of this code. Where second-story exterior walls are of light-framed construction, they shall be designed and constructed as required by this code.

Aspects of concrete construction not specifically addressed by this code, including interior concrete walls, shall comply with ACI 318.

Exterior concrete walls constructed in accordance with this code shall comply with the shapes and minimum concrete cross-sectional dimensions of Table R608.3. Other types of forming systems resulting in concrete walls not in compliance with this section shall be designed in accordance with ACI 318.

The provisions of this section shall apply to the construction of exterior concrete walls for buildings not greater than 60 feet (18 288 mm) in plan dimensions, floors with clear spans not greater than 32 feet (9754 mm) and roofs with clear spans not greater than 40 feet (12 192 mm). Buildings shall not exceed 35 feet (10 668 mm) in mean roof height or two stories in height above grade. Floor/ceiling dead loads shall not exceed 10 pounds per square foot (479 Pa), roof/ceiling dead loads shall not exceed 15 pounds per square foot (718 Pa) and attic live loads shall not exceed 20 pounds per square foot (958 Pa). Roof overhangs shall not exceed 2 feet (610 mm) of horizontal projection beyond the exterior wall and the dead load of the overhangs shall not exceed 8 pounds per square foot (383 Pa).

Walls constructed in accordance with the provisions of this section shall be limited to buildings subjected to a maximum design wind speed of 160 mph (72 m/s) Exposure B, 136 mph (61 m/s) Exposure C and 125 mph (56 m/s) Exposure D. Walls constructed in accordance with the provisions of this section shall be limited to detached one- and two-family dwellings and townhouses assigned to Seismic Design Category A or B, and detached one- and two-family dwellings assigned to Seismic Design Category C.

Buildings that are not within the scope of this section shall be designed in accordance with PCA 100 or ACI 318.

Concrete walls constructed in accordance with these provisions shall comply with the shapes and minimum concrete cross-sectional dimensions of Table R608.3.

TABLE R608.3

DIMENSIONAL REQUIREMENTS FOR WALLSa, b

WALL TYPE
AND NOMINAL
THICKNESS
MAXIMUM
WALL WEIGHTc
(psf)
MINIMUM
WIDTH, W, OF
VERTICAL CORES
(inches)
MINIMUM
THICKNESS, T, OF
VERTICAL CORES
(inches)
MAXIMUM
SPACING OF
VERTICAL CORES
(inches)
MAXIMUM
SPACING OF
HORIZONTAL
CORES (inches)
MINIMUM WEB
THICKNESS
(inches)
4" Flatd 50 N/A N/A N/A N/A N/A
6" Flatd 75 N/A N/A N/A N/A N/A
8" Flatd 100 N/A N/A N/A N/A N/A
10" Flatd 125 N/A N/A N/A N/A N/A
6" Waffle-grid 56 8e 5.5e 12 16 2
8" Waffle-grid 76 8f 8f 12 16 2
6" Screen-grid 53 6.25g 6.25g 12 12 N/A

For SI: 1 inch = 25.4 mm; 1 pound per square foot = 0.0479 kPa, 1 pound per cubic foot = 2402.77 kg/m3, 1 square inch = 645.16 mm2, 1 inch4 = 42 cm4.

  1. Width "W," thickness "T," spacing and web thickness, refer to Figures R608.3(2) and R608.3(3).
  2. N/A indicates not applicable.
  3. Wall weight is based on a unit weight of concrete of 150 pcf. For flat walls the weight is based on the nominal thickness. The tabulated values do not include any allowance for interior and exterior finishes.
  4. Nominal wall thickness. The actual as-built thickness of a flat wall shall not be more than 1/2 inch less or more than 1/4 inch more than the nominal dimension indicated.
  5. Vertical core is assumed to be elliptical-shaped. Another shape core is permitted provided the minimum thickness is 5 inches, the moment of inertia, I, about the centerline of the wall (ignoring the web) is not less than 65 inch4, and the area, A, is not less than 31.25 square inches. The width used to calculate A and I shall not exceed 8 inches.
  6. Vertical core is assumed to be circular. Another shape core is permitted provided the minimum thickness is 7 inches, the moment of inertia, I, about the centerline of the wall (ignoring the web) is not less than 200 inch4, and the area, A, is not less than 49 square inches. The width used to calculate A and I shall not exceed 8 inches.
  7. Vertical core is assumed to be circular. Another shape core is permitted provided the minimum thickness is 5.5 inches, the moment of inertia, I, about the centerline of the wall is not less than 76 inch4, and the area, A, is not less than 30.25 square inches. The width used to calculate A and I shall not exceed 6.25 inches.

SEE TABLE 608.3 FOR MINIMUM DIMENSIONS

FIGURE R608.3(1)

FLAT WALL SYSTEM

SEE TABLE R608.3 FOR MINIMUM DIMENSIONS

For SI: 1 inch = 25.4 mm.

FIGURE R608.3(2)

WAFFLE-GRID WALL SYSTEM

SEE TABLE R608.3 FOR MINIMUM DIMENSIONS

For SI: 1 inch = 25.4 mm.

FIGURE R608.3(3)

SCREEN-GRID WALL SYSTEM

Flat concrete wall systems shall comply with Table R608.3 and Figure R608.3(1) and have a minimum nominal thickness of 4 inches (102 mm).
Waffle-grid wall systems shall comply with Table R608.3 and Figure R608.3(2) and shall have a minimum nominal thickness of 6 inches (152 mm) for the horizontal and vertical concrete members (cores). The core and web dimensions shall comply with Table R608.3. The maximum weight of waffle-grid walls shall comply with Table R608.3.
Screen-grid wall systems shall comply with Table R608.3 and Figure R608.3(3) and shall have a minimum nominal thickness of 6 inches (152 mm) for the horizontal and vertical concrete members (cores). The core dimensions shall comply with Table R608.3. The maximum weight of screen-grid walls shall comply with Table R608.3.
Stay-in-place concrete forms shall comply with this section.
The flame spread index and smoke-developed index of forming material, other than foam plastic, left exposed on the interior shall comply with Section R302.9. The surface burning characteristics of foam plastic used in insulating concrete forms shall comply with Section R316.3.
Stay-in-place forms constructed of rigid foam plastic shall be protected on the interior of the building as required by Sections R316.4 and R702.3.4. Where gypsum board is used to protect the foam plastic, it shall be installed with a mechanical fastening system. Use of adhesives is permitted in addition to mechanical fasteners.

Stay-in-place forms constructed of rigid foam plastics shall be protected from sunlight and physical damage by the application of an approved exterior wall covering complying with this code. Exterior surfaces of other stay-in-place forming systems shall be protected in accordance with this code.

Requirements for installation of masonry veneer, stucco and other finishes on the exterior of concrete walls and other construction details not covered in this section shall comply with the requirements of this code.

Flat ICF wall system forms shall conform to ASTM E2634.

R608.5 Materials

ILLUSTRATION
Materials used in the construction of concrete walls shall comply with this section.
Materials used in concrete, and the concrete itself, shall conform to requirements of this section, PCA 100 or ACI 318.

The following standards as referenced in Chapter 46 shall be permitted to be used.

  1. ASTM C150
  2. ASTM C595
  3. ASTM C1157
Mixing and delivery of concrete shall comply with ASTM C94 or ASTM C685.

The nominal maximum size of coarse aggregate shall not exceed onefifth the narrowest distance between sides of forms, or three-fourths the clear spacing between reinforcing bars or between a bar and the side of the form.

Exception: When approved, these limitations shall not apply where removable forms are used and workability and methods of consolidation permit concrete to be placed without honeycombs or voids.

Proportions of materials for concrete shall be established to provide workability and consistency to permit concrete to be worked readily into forms and around reinforcement under conditions of placement to be employed, without segregation or excessive bleeding. Slump of concrete placed in removable forms shall not exceed 6 inches (152 mm).

Exception: When approved, the slump is permitted to exceed 6 inches (152 mm) for concrete mixtures that are resistant to segregation, and are in accordance with the form manufacturer's recommendations.

Slump of concrete placed in stay-in-place forms shall exceed 6 inches (152 mm). Slump of concrete shall be determined in accordance with ASTM C143.

The minimum specified compressive strength of concrete, f'c, shall comply with Section R402.2 and shall be not less than 2,500 pounds per square inch (17.2 MPa) at 28 days.

Concrete shall be consolidated by suitable means during placement and shall be worked around embedded items and reinforcement and into corners of forms. Where stay-in-place forms are used, concrete shall be consolidated by internal vibration.

Exception: When approved, self-consolidating concrete mixtures with slumps equal to or greater than 8 inches (203 mm) that are specifically designed for placement without internal vibration need not be internally vibrated.

Steel reinforcement shall comply with ASTM A615, ASTM A706, or ASTM A996. ASTM A996 bars produced from rail steel shall be Type R.
Anchor bolts for use with connection details in accordance with Figures R608.9(1) through R608.9(12) shall be bolts with heads complying with ASTM A307 or ASTM F1554. ASTM A307 bolts shall be Grade A with heads. ASTM F1554 bolts shall be Grade 36 minimum. Instead of bolts with heads, it is permissible to use rods with threads on both ends fabricated from steel complying with ASTM A36. The threaded end of the rod to be embedded in the concrete shall be provided with a hex or square nut.
Angles and tension tie straps for use with connection details in accordance with Figures R608.9(1) through R608.9(12) shall be fabricated from sheet steel complying with ASTM A653 SS, ASTM A792 SS, or ASTM A875 SS. The steel shall be minimum Grade 33 unless a higher grade is required by the applicable figure.

Forms shall be made of wood, steel, aluminum, plastic, a composite of cement and foam insulation, a composite of cement and wood chips, or other approved material suitable for supporting and containing concrete. Forms shall provide sufficient strength to contain concrete during the concrete placement operation.

Form ties shall be steel, solid plastic, foam plastic, a composite of cement and wood chips, a composite of cement and foam plastic, or other suitable material capable of resisting the forces created by fluid pressure of fresh concrete.

TABLE R608.5.4(1)

LAP SPLICE AND TENSION DEVELOPMENT LENGTHS

BAR SIZE
NO.
YIELD STRENGTH OF STEEL, fy- psi (MPa)
40,000 (280) 60,000 (420)
Splice length or tension development length
(inches)
Lap splice length-tension 4 20 30
5 25 38
6 30 45
Tension development length for straight bar 4 15 23
5 19 28
6 23 34
Tension development length for:
  1. 90-degree and 180-degree standard hooks with not less than 21/2 inches
    of side cover perpendicular to plane of hook, and
  2. 90-degree standard hooks with not less than 2 inches of cover on the bar
    extension beyond the hook.
4 6 9
5 7 11
6 8 13
Tension development length for bar with 90-degree or 180-degree standard
hook having less cover than required above.
4 8 12
5 10 15
6 12 18

For SI: 1 inch = 25.4 mm.

For SI: 1 inch = 25.4 mm.

FIGURE R608.5.4(1)

LAP SPLICES

For SI: 1 degree = 0.0175 rad.

FIGURE R608.5.4(2)

DEVELOPMENT LENGTH AND COVER FOR HOOKS AND BAR EXTENSION

TABLE R608.5.4(2)

MAXIMUM SPACING FOR ALTERNATIVE BAR SIZE AND/OR ALTERNATIVE GRADE OF STEELa, b, c

BAR SPACING FROM
APPLICABLE TABLE IN
SECTION R608.6
(inches)
BAR SIZE FROM APPLICABLE TABLE IN SECTION R608.6
#4 #5 #6
Alternate bar size and/or alternate grade of steel desired
Grade 60 Grade 40 Grade 60 Grade 40 Grade 60 Grade 40
#5 #6 #4 #5 #6 #4 #6 #4 #5 #6 #4 #5 #4 #5 #6
Maximum spacing for alternate bar size and/or alternate grade of steel (inches)
8 12 18 5 8 12 5 11 3 5 8 4 6 2 4 5
9 14 20 6 9 13 6 13 4 6 9 4 6 3 4 6
10 16 22 7 10 15 6 14 4 7 9 5 7 3 5 7
11 17 24 7 11 16 7 16 5 7 10 5 8 3 5 7
12 19 26 8 12 18 8 17 5 8 11 5 8 4 6 8
13 20 29 9 13 19 8 18 6 9 12 6 9 4 6 9
14 22 31 9 14 21 9 20 6 9 13 6 10 4 7 9
15 23 33 10 16 22 10 21 6 10 14 7 11 5 7 10
16 25 35 11 17 23 10 23 7 11 15 7 11 5 8 11
17 26 37 11 18 25 11 24 7 11 16 8 12 5 8 11
18 28 40 12 19 26 12 26 8 12 17 8 13 5 8 12
19 29 42 13 20 28 12 27 8 13 18 9 13 6 9 13
20 31 44 13 21 29 13 28 9 13 19 9 14 6 9 13
21 33 46 14 22 31 14 30 9 14 20 10 15 6 10 14
22 34 48 15 23 32 14 31 9 15 21 10 16 7 10 15
23 36 48 15 24 34 15 33 10 15 22 10 16 7 11 15
24 37 48 16 25 35 15 34 10 16 23 11 17 7 11 16
25 39 48 17 26 37 16 35 11 17 24 11 18 8 12 17
26 40 48 17 27 38 17 37 11 17 25 12 18 8 12 17
27 42 48 18 28 40 17 38 12 18 26 12 19 8 13 18
28 43 48 19 29 41 18 40 12 19 26 13 20 8 13 19
29 45 48 19 30 43 19 41 12 19 27 13 20 9 14 19
30 47 48 20 31 44 19 43 13 20 28 14 21 9 14 20
31 48 48 21 32 45 20 44 13 21 29 14 22 9 15 21
32 48 48 21 33 47 21 45 14 21 30 15 23 10 15 21
33 48 48 22 34 48 21 47 14 22 31 15 23 10 16 22
34 48 48 23 35 48 22 48 15 23 32 15 24 10 16 23
35 48 48 23 36 48 23 48 15 23 33 16 25 11 16 23
36 48 48 24 37 48 23 48 15 24 34 16 25 11 17 24
37 48 48 25 38 48 24 48 16 25 35 17 26 11 17 25
38 48 48 25 39 48 25 48 16 25 36 17 27 12 18 25
39 48 48 26 40 48 25 48 17 26 37 18 27 12 18 26
40 48 48 27 41 48 26 48 17 27 38 18 28 12 19 27
41 48 48 27 42 48 26 48 18 27 39 19 29 12 19 27
42 48 48 28 43 48 27 48 18 28 40 19 30 13 20 28
43 48 48 29 44 48 28 48 18 29 41 20 30 13 20 29
44 48 48 29 45 48 28 48 19 29 42 20 31 13 21 29
45 48 48 30 47 48 29 48 19 30 43 20 32 14 21 30
46 48 48 31 48 48 30 48 20 31 44 21 32 14 22 31
47 48 48 31 48 48 30 48 20 31 44 21 33 14 22 31
48 48 48 32 48 48 31 48 21 32 45 22 34 15 23 32

For SI: 1 inch = 25.4 mm.

  1. This table is for use with tables in Section R608.6 that specify the minimum bar size and maximum spacing of vertical wall reinforcement for foundation walls and above-grade walls. Reinforcement specified in tables in Section R608.6 is based on Grade 60 (420 MPa) steel reinforcement.
  2. Bar spacing shall not exceed 48 inches on center and shall be not less than one-half the nominal wall thickness.
  3. For Grade 50 (350 MPa) steel bars (ASTM A996, Type R), use spacing for Grade 40 (280 MPa) bars or interpolate between Grade 40 (280 MPa) and Grade 60 (420 MPa).

For SI: 1 inch = 25.4 mm, 1 degree = 0.0175 rad.

FIGURE R608.5.4(3)

STANDARD HOOKS

Reinforcement shall be secured in the proper location in the forms with tie wire or other bar support system such that displacement will not occur during the concrete placement operation. Steel reinforcement in concrete cast against the earth shall have a minimum cover of 3 inches (76 mm). Minimum cover for reinforcement in concrete cast in removable forms that will be exposed to the earth or weather shall be 11/2 inches (38 mm) for No. 5 bars and smaller, and 2 inches (50 mm) for No. 6 bars and larger. For concrete cast in removable forms that will not be exposed to the earth or weather, and for concrete cast in stay-in-place forms, minimum cover shall be 3/4 inch (19 mm). The minus tolerance for cover shall not exceed the smaller of one-third the required cover and 3/8 inch (10 mm). See Section R608.5.4.4 for cover requirements for hooks of bars developed in tension.
For location of reinforcement in foundation walls and above-grade walls, see Sections R404.1.3.3.7.2 and R608.6.5, respectively.
Vertical and horizontal wall reinforcement required by Sections R608.6 and R608.7 shall be the longest lengths practical. Where splices are necessary in reinforcement, the length of lap splices shall be in accordance with Table R608.5.4(1) and Figure R608.5.4(1). The maximum gap between noncontact parallel bars at a lap splice shall not exceed the smaller of one-fifth the required lap length and 6 inches (152 mm). See Figure R608.5.4(1).
Where bars are required to be developed in tension by other provisions of this code, development lengths and cover for hooks and bar extensions shall comply with Table R608.5.4(1) and Figure R608.5.4(2). The development lengths shown in Table R608.5.4(1) shall apply to bundled bars in lintels installed in accordance with Section R608.8.2.2.
Where reinforcement is required by this code to terminate with a standard hook, the hook shall comply with Figure R608.5.4(3).
Reinforcement, including stirrups, shall not be placed in webs of wafflegrid walls, including lintels. Webs are permitted to have form ties.
Where tables in Sections R404.1.3 and R608.6 specify vertical wall reinforcement based on minimum bar size and maximum spacing, which are based on Grade 60 (420 MPa) steel reinforcement, different size bars or bars made from a different grade of steel are permitted provided an equivalent area of steel per linear foot of wall is provided. Use of Table R608.5.4(2) is permitted to determine the maximum bar spacing for different bar sizes than specified in the tables and/or bars made from a different grade of steel. Bars shall not be spaced less than one-half the wall thickness, or more than 48 inches (1219 mm) on center.

Construction joints shall be made and located to not impair the strength of the wall. Construction joints in plain concrete walls, including walls required to have not less than No. 4 bars at 48 inches (1219 mm) on center by Section R608.6, shall be located at points of lateral support, and not less than one No. 4 bar shall extend across the construction joint at a spacing not to exceed 24 inches (610 mm) on center. Construction joint reinforcement shall have not less than 12 inches (305 mm) embedment on both sides of the joint. Construction joints in reinforced concrete walls shall be located in the middle third of the span between lateral supports, or located and constructed as required for joints in plain concrete walls.

Exception: Vertical wall reinforcement required by this code is permitted to be used in lieu of construction joint reinforcement, provided the spacing does not exceed 24 inches (610 mm), or the combination of wall reinforcement and No. 4 bars described in Section R608.5.5 does not exceed 24 inches (610 mm).

For SI: 1 foot = 304.8 mm.

FIGURE R608.6(1)

ABOVE-GRADE CONCRETE WALL CONSTRUCTION ONE STORY

For SI: 1 foot = 304.8 mm.

FIGURE R608.6(2)

ABOVE-GRADE CONCRETE WALL CONSTRUCTION CONCRETE FIRST STORY AND LIGHT-FRAMED SECOND STORY

For SI: 1 foot = 304.8 mm.

FIGURE R608.6(3)

ABOVE-GRADE CONCRETE WALL CONSTRUCTION TWO-STORY

For SI: 1inch=25.4mm.

FIGURE R608.6(4)

ABOVE-GRADE CONCRETE WALL SUPPORTED ON MONOLITHIC SLAB-ON-GROUND FOOTING

TABLE R608.6(1)

MINIMUM VERTICAL REINFORCEMENT FOR FLAT ABOVE-GRADE WALLSa, b, c, d, e

MAXIMUM WIND SPEED
(mph)
MAXIMUM UNSUPPORTED
WALL HEIGHT PER STORY
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)f, g
Nominalh wall thickness (inches)
Exposure Category 4 6 8 10
B C D Topi Sidei Topi Sidei Topi Sidei Topi Sidei
115 8 4@48 4@48 4@48 4@48 4@48 4@48 4@48 4@48
9 4@48 4@39 4@48 4@48 4@48 4@48 4@48 4@48
10 4@41 4@34 4@48 4@48 4@48 4@48 4@48 4@48
120 8 4@48 4@43 4@48 4@48 4@48 4@48 4@48 4@48
9 4@48 4@36 4@48 4@48 4@48 4@48 4@48 4@48
10 4@37 4@34 4@48 4@48 4@48 4@48 4@48 4@48
130 110 8 4@48 4@38 4@48 4@48 4@48 4@48 4@48 4@48
9 4@39 4@34 4@48 4@48 4@48 4@48 4@48 4@48
10 4@34 4@34 4@48 4@48 4@48 4@48 4@48 4@48
140 119 110 8 4@43 4@34 4@48 4@48 4@48 4@48 4@48 4@48
9 4@34 4@34 4@48 4@48 4@48 4@48 4@48 4@48
10 4@34 4@31 4@48 4@48 4@48 4@48 4@48 4@48
150 127 117 8 4@37 4@34 4@48 4@48 4@48 4@48 4@48 4@48
9 4@34 4@33 4@48 4@48 4@48 4@48 4@48 4@48
10 4@31 4@27 4@48 4@48 4@48 4@48 4@48 4@48
160 136 125 8 4@34 4@34 4@48 4@48 4@48 4@48 4@48 4@48
9 4@34 4@29 4@48 4@48 4@48 4@48 4@48 4@48
10 4@27 4@24 4@48 4@48 4@48 4@48 4@48 4@48

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square inch = 1.895 kPa, 1 square foot = 0.0929 m2.

  1. Table is based on ASCE 7 components and cladding wind pressures for an enclosed building using a mean roof height of 35 feet, interior wall area 4, an effective wind area of 10 square feet, topographic factor, Kzt, equal to 1.0, and Risk Category II.
  2. Table is based on concrete with a minimum specified compressive strength of 2,500 psi.
  3. See Section R608.6.5 for location of reinforcement in wall.
  4. Deflection criterion is L/240, where L is the unsupported height of the wall in inches.
  5. Interpolation is not permitted.
  6. Where No. 4 reinforcing bars at a spacing of 48 inches are specified in the table as indicated by shaded cells, use of bars with a minimum yield strength of 40,000 psi or 60,000 psi is permitted.
  7. Other than for No. 4 bars spaced at 48 inches on center, table values are based on reinforcing bars with a minimum yield strength of 60,000 psi. Vertical reinforcement with a yield strength of less than 60,000 psi or bars of a different size than specified in the table are permitted in accordance with Section R608.5.4.7 and Table R608.5.4(2).
  8. See Table R608.3 for tolerances on nominal thicknesses.
  9. "Top" means gravity load from roof or floor construction bears on top of wall. "Side" means gravity load from floor construction is transferred to wall from a wood ledger or cold-formed steel track bolted to side of wall. For nonload-bearing walls where floor framing members span parallel to the wall, use of the "Top" bearing condition is permitted.

TABLE R608.6(2)

MINIMUM VERTICAL REINFORCEMENT FOR WAFFLE-GRID ABOVE-GRADE WALLSa, b, c, d, e

MAXIMUM WIND SPEED
(mph)
MAXIMUM UNSUPPORTED
WALL HEIGHT PER STORY
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)f, g
Nominalh wall thickness (inches)
Exposure Category 6 8
B C D Topi Sidei Topi Sidei
115 8 4@48 4@48 4@48 4@48
9 4@48 5@43 4@48 4@48
10 5@47 5@37 4@48 4@48
120 8 4@48 5@48 4@48 4@48
9 4@48 5@40 4@48 4@48
10 5@43 5@37 4@48 4@48
130 110 8 4@48 5@42 4@48 4@48
9 5@45 5@37 4@48 4@48
10 5@37 5@37 4@48 4@48
140 119 110 8 4@48 5@38 4@48 4@48
9 5@39 5@37 4@48 4@48
10 5@37 5@35 4@48 4@48
150 127 117 8 5@43 5@37 4@48 4@48
9 5@37 5@37 4@48 4@48
10 5@36 6@44 4@48 4@48
160 136 125 8 5@38 5@37 4@48 4@48
9 5@37 6@47 4@48 4@48
10 6@45 6@39 4@48 6@46

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square inch = 6.895 kPa, 1 square foot = 0.0929 m2.

  1. Table is based on ASCE 7 components and cladding wind pressures for an enclosed building using a mean roof height of 35 feet, interior wall area 4, an effective wind area of 10 square feet, topographic factor, Kzt, equal to 1.0, and Risk Category II.
  2. Table is based on concrete with a minimum specified compressive strength of 2,500 psi.
  3. See Section R608.6.5 for location of reinforcement in wall.
  4. Deflection criterion is L/240, where L is the unsupported height of the wall in inches.
  5. Interpolation is not permitted.
  6. Where No. 4 reinforcing bars at a spacing of 48 inches are specified in the table as indicated by shaded cells, use of bars with a minimum yield strength of 40,000 psi or 60,000 psi is permitted.
  7. Other than for No. 4 bars spaced at 48 inches on center, table values are based on reinforcing bars with a minimum yield strength of 60,000 psi. 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 such as, 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 or bars of a different size than specified in the table are permitted in accordance with Section R608.5.4.7 and Table R608.5.4(2).
  8. See Table R608.3 for minimum core dimensions and maximum spacing of horizontal and vertical cores.
  9. "Top" means gravity load from roof or floor construction bears on top of wall. "Side" means gravity load from floor construction is transferred to wall from a wood ledger or cold-formed steel track bolted to side of wall. For nonload-bearing walls and where floor framing members span parallel to the wall, the "top" bearing condition is permitted to be used.

TABLE R608.6(3)

MINIMUM VERTICAL REINFORCEMENT FOR 6-INCH SCREEN-GRID ABOVE-GRADE WALLSa, b, c, d, e

MAXIMUM WIND SPEED
(mph)
MAXIMUM UNSUPPORTED
WALL HEIGHT PER STORY
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)f, g
Nominalh wall thickness (inches)
Exposure Category 6
B C D Topi Sidei
115 8 4@48 4@48
9 4@48 5@41
10 4@48 6@48
120 8 4@48 4@48
9 4@48 5@38
10 5@42 6@48
130 110 8 4@48 5@41
9 5@44 6@48
10 5@35 6@48
140 119 110 8 4@48 5@36
9 5@38 6@48
10 6@48 6@48
150 127 117 8 5@42 6@48
9 6@48 6@48
10 6@48 6@42
160 136 125 8 5@37 6@48
9 6@48 6@45
10 6@44 6@38

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square inch = 6.895 kPa, 1 square foot = 0.0929 m2.

  1. Table is based on ASCE 7 components and cladding wind pressures for an enclosed building using a mean roof height of 35 feet, interior wall area 4, an effective wind area of 10 square feet, topographic factor, Kzt, equal to 1.0, and Risk Category II.
  2. Table is based on concrete with a minimum specified compressive strength of 2,500 psi.
  3. See Section R608.6.5 for location of reinforcement in wall.
  4. Deflection criterion is L/240, where L is the unsupported height of the wall in inches.
  5. Interpolation is not permitted.
  6. Where No. 4 reinforcing bars at a spacing of 48 inches are specified in the table as indicated by shaded cells, use of bars with a minimum yield strength of 40,000 psi or 60,000 psi is permitted.
  7. Other than for No. 4 bars spaced at 48 inches on center, table values are based on reinforcing bars with a minimum yield strength of 60,000 psi. 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 such as, 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 or bars of a different size than specified in the table are permitted in accordance with Section R608.5.4.7 and Table R608.5.4(2).
  8. See Table R608.3 for minimum core dimensions and maximum spacing of horizontal and vertical cores.
  9. "Top" means gravity load from roof or floor construction bears on top of wall. "Side" means gravity load from floor construction is transferred to wall from a wood ledger or cold-formed steel track bolted to side of wall. For nonload-bearing wall and where floor framing members span parallel to the wall, use of the "Top" bearing condition is permitted.

TABLE R608.6(4)

MINIMUM VERTICAL REINFORCEMENT FOR FLAT, WAFFLE- AND SCREEN-GRID ABOVE-GRADE WALLS DESIGNED CONTINUOUS WITH FOUNDATION STEM WALLSa, b, c, d, e, k, l

MAXIMUM WIND SPEED
(mph)
HEIGHT OF
STEM WALLh, i
(feet)
MAXIMUM
DESIGN
LATERAL
SOIL LOAD
(psf/ft)
MAXIMUM
UNSUPPORTED
HEIGHT OF ABOVE-
GRADE WALL
(feet)
MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (inches)f, g
Wall type and nominal thicknessj (inches)
Exposure Category Flat Waffle Screen
B C D 4 6 8 10 6 8 6
115 3 30 8 4@30 4@48 4@48 4@48 4@22 4@26 4@21
10 4@23 5@43 4@48 4@48 4@17 4@20 4@16
60 10 4@19 5@37 4@48 4@48 4@14 4@17 4@14
6 30 10 DR 5@21 6@35 4@48 DR 4@10 DR
60 10 DR 5@12 6@25 6@28 DR DR DR
120 3 30 8 4@28 4@48 4@48 4@48 4@21 4@48 4@20
10 4@22 5@41 4@48 4@48 4@16 4@19 4@15
60 10 4@18 5@35 4@48 4@48 4@14 4@17 4@13
6 30 10 DR 5@21 6@35 4@48 DR 4@10 DR
60 10 DR 5@12 6@25 6@28 DR DR DR
130 110 3 30 8 4@25 4@48 4@48 4@48 4@18 4@22 4@18
10 4@19 5@36 4@48 4@48 4@14 4@17 4@13
6 60 10 4@16 5@34 4@48 4@48 4@12 4@17 4@12
30 10 DR 5@19 6@35 4@48 DR 4@9 DR
60 10 DR 5@12 6@24 6@28 DR DR DR
140 119 110 3 30 8 4@22 5@42 4@48 4@48 4@16 4@20 4@16
10 4@17 5@34 4@48 4@48 4@21 4@17 4@12
60 10 4@15 5@34 4@48 4@48 4@11 4@17 4@10
6 30 10 DR 5@18 6@35 6@35 DR 4@48 DR
60 10 DR 5@11 6@23 6@28 DR DR DR
150 127 117 3 30 8 4@20 5@37 4@48 4@48 4@15 4@18 4@14
10 4@15 5@34 4@48 4@48 4@11 4@17 4@11
60 10 4@13 5@34 4@48 4@48 4@10 4@16 4@9
6 30 10 DR 5@17 6@33 6@32 DR 4@8 DR
60 10 DR DR 6@22 6@28 DR DR DR
160 136 125 3 30 8 4@18 5@34 4@48 4@48 4@13 4@17 4@13
10 4@13 5@34 4@48 4@48 4@10 4@16 4@9
60 10 4@11 5@31 6@45 4@48 4@9 4@14 4@8
6 30 10 DR 5@15 6@31 6@30 DR 4@7 DR
60 10 DR DR 6@21 6@27 DR DR DR

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square inch = 6.895 kPa, 1 square foot = 0.0929 m2.

  1. Table is based on ASCE 7 components and cladding wind pressures for an enclosed building using a mean roof height of 35 feet, interior wall area 4, an effective wind area of 10 square feet, topographic factor, Kzt, equal to 1.0, and Risk Category II.
  2. Table is based on concrete with a minimum specified compressive strength of 2,500 psi.
  3. See Section R608.6.5 for location of reinforcement in wall.
  4. Deflection criterion is L/240, where L is the height of the wall in inches from the exterior finish ground level to the top of the above-grade wall.
  5. Interpolation is not permitted. For intermediate values of basic wind speed, heights of stem wall and above-grade wall, and design lateral soil load, use next higher value.
  6. Where No. 4 reinforcing bars at a spacing of 48 inches are specified in the table as indicated by shaded cells, use of bars with a minimum yield strength of 40,000 psi or 60,000 psi is permitted.
  7. Other than for No. 4 bars spaced at 48 inches on center, table values are based on reinforcing bars with a minimum yield strength of 60,000 psi. Maximum spacings shown are the values calculated for the specified bar size. In waffle and screen-grid walls 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 such as, 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 R608.5.4.7 and Table R608.5.4(2).
  8. Height of stem wall is the distance from the exterior finish ground level to the top of the slab-on-ground.
  9. Where the distance from the exterior finish ground level to the top of the slab-on-ground is equal to or greater than 4 feet, the stem wall shall be laterally supported at the top and bottom before backfilling. Where the wall is designed and constructed to be continuous with the above-grade wall, temporary supports bracing the top of the stem wall shall remain in place until the above-grade wall is laterally supported at the top by floor or roof construction.
  10. See Table R608.3 for tolerances on nominal thicknesses, and minimum core dimensions and maximum spacing of horizontal and vertical cores for waffle- and screen-grid walls.
  11. Tabulated values are applicable to construction where gravity loads bear on top of wall, and conditions where gravity loads from floor construction are transferred to wall from a wood ledger or cold-formed steel track bolted to side of wall. See Tables R608.6(1), R608.6(2) and R608.6(3).
  12. DR = Design Required.

The minimum thickness of load-bearing and nonload-bearing above-grade walls and reinforcement shall be as set forth in the appropriate table in this section based on the type of wall form to be used. The wall shall be designed in accordance with ACI 318 where the wall or building is not within the limitations of Section R608.2, where design is required by the tables in this section or where the wall is not within the scope of the tables in this section.

Above-grade concrete walls shall be constructed in accordance with this section and Figure R608.6(1), R608.6(2), R608.6(3) or R608.6(4). Above-grade concrete walls that are continuous with stem walls and not laterally supported by the slab-on-ground shall be designed and constructed in accordance with this section. Concrete walls shall be supported on continuous foundation walls or slabson-ground that are monolithic with the footing in accordance with Section R403. The minimum length of solid wall without openings shall be in accordance with Section R608.7. Reinforcement around openings, including lintels, shall be in accordance with Section R608.8. Lateral support for above-grade walls in the out-of-plane direction shall be provided by connections to the floor framing system, if applicable, and to ceiling and roof framing systems in accordance with Section R608.9. The wall thickness shall be equal to or greater than the thickness of the wall in the story above.

Vertical wall reinforcement for resistance to out-of-plane wind forces shall be determined from Table R608.6(1), R608.6(2), R608.6(3) or R608.6(4). For the design of nonload-bearing walls, in Tables R608.6(1), R608.6(2) and R608.6(3) use the appropriate column labeled "Top." (see Sections R608.7.2.2.2 and R608.7.2.2.3). There shall be a vertical bar at corners of exterior walls. Unless more horizontal reinforcement is required by Section R608.7.2.2.1, the minimum horizontal reinforcement shall be four No. 4 bars [Grade 40 (280 MPa)] placed as follows: top bar within 12 inches (305 mm) of the top of the wall, bottom bar within 12 inches (305 mm) of the finish floor and one bar each at approximately one-third and two-thirds of the wall height.

Vertical reinforcement required by this section shall be continuous between elements providing lateral support for the wall. Reinforcement in the wall of the story above shall be continuous with the reinforcement in the wall of the story below, or the foundation wall, if applicable. Lap splices, where required, shall comply with Section R608.5.4.3 and Figure R608.5.4(1). Where the above-grade wall is supported by a monolithic slab-on-ground and footing, dowel bars with a size and spacing to match the vertical above-grade concrete wall reinforcement shall be embedded in the monolithic slab-on-ground and footing the distance required to develop the dowel bar in tension in accordance with Section R608.5.4.4 and Figure R608.5.4(2) and lap-spliced with the above-grade wall reinforcement in accordance with Section R608.5.4.3 and Figure R608.5.4(1).

Exception: Where reinforcement in the wall above cannot be made continuous with the reinforcement in the wall below, the bottom of the reinforcement in the wall above shall be terminated in accordance with one of the following:

  1. Extend below the top of the floor the distance required to develop the bar in tension in accordance with Section R608.5.4.4 and Figure R608.5.4(2).
  2. Lap-spliced in accordance with Section R608.5.4.3 and Figure R608.5.4(1) with a dowel bar that extends into the wall below the distance required to develop the bar in tension in accordance with Section R608.5.4.4 and Figure R608.5.4(2).

Where a construction joint in the wall is located below the level of the floor and less than the distance required to develop the bar in tension, the distance required to develop the bar in tension shall be measured from the top of the concrete below the joint. See Section R608.5.5.

Where indicated in Items 1 through 3, vertical wall reinforcement in the top-most story with concrete walls shall be terminated with a 90-degree (1.57 rad) standard hook complying with Section R608.5.4.5 and Figure R608.5.4(3).

  1. Vertical bars adjacent to door and window openings required by Section R608.8.1.2.
  2. Vertical bars at the ends of required solid wall segments (see Section R608.7.2.2.2).
  3. Vertical bars (other than end bars, see Item 2) used as shear reinforcement in required solid wall segments where the reduction factor for design strength, R3, used is based on the wall having horizontal and vertical shear reinforcement (see Section R608.7.2.2.3).

The bar extension of the hook shall be oriented parallel to the horizontal wall reinforcement and be within 4 inches (102 mm) of the top of the wall.

Horizontal reinforcement shall be continuous around the building corners by bending one of the bars and lapsplicing it with the bar in the other wall in accordance with Section R608.5.4.3 and Figure R608.5.4(1).

Exception: In lieu of bending horizontal reinforcement at corners, separate bent reinforcing bars shall be permitted provided that the bent bar is lap-spliced with the horizontal reinforcement in both walls in accordance with Section R608.5.4.3 and Figure R608.5.4(1).

In required solid wall segments where the reduction factor for design strength, R3, is based on the wall having horizontal and vertical shear reinforcement in accordance with Section R608.7.2.2.1, horizontal wall reinforcement shall be terminated with a standard hook complying with Section R608.5.4.5 and Figure R608.5.4(3) or in a lapsplice, except at corners where the reinforcement shall be continuous as required.

Except for vertical reinforcement at the ends of required solid wall segments, which shall be located as required by Section R608.7.2.2.2, the location of the vertical reinforcement shall not vary from the center of the wall by more than the greater of 10 percent of the wall thickness and 3/8-inch (10 mm). Horizontal and vertical reinforcement shall be located to provide not less than the minimum cover required by Section R608.5.4.1.

TABLE R608.7(1A)

UNREDUCED LENGTH, UR, OF SOLID WALL REQUIRED IN EACH EXTERIOR ENDWALL FOR WIND PERPENDICULAR TO RIDGE ONE STORY OR TOP STORY OF TWO STORYa, c, d, e, f, g

SIDEWALL
LENGTH
(feet)
ENDWALL
LENGTH
(feet)
ROOF UNREDUCED LENGTH, UR, OF SOLID WALL REQUIRED IN ENDWALLS FOR WIND PERPENDICULAR TO RIDGE
(feet)
Basic Wind Speed (mph) Exposure
115B 120B 130B 140B 150B 160B Minimumb
110C 119C 127C 136C
110D 117D 125D
15 15 < 1:12 1.03 1.12 1.32 1.53 1.76 2.00 0.92
5:12 1.43 1.56 1.83 2.12 2.43 2.77 1.15
7:12 2.00 2.18 2.56 2.97 3.41 3.88 1.25
12:12 3.20 3.48 4.09 4.74 5.44 6.19 1.54
30 < 1:12 1.03 1.12 1.32 1.53 1.76 2.00 0.98
5:12 1.43 1.56 1.83 2.12 2.43 2.77 1.43
7:12 2.78 3.03 3.56 4.13 4.74 5.39 1.64
12:12 5.17 5.63 6.61 7.67 8.80 10.01 2.21
45 < 1:12 1.03 1.12 1.32 1.53 1.76 2.00 1.04
5:12 1.43 1.56 1.83 2.12 2.43 2.77 1.72
7:12 3.57 3.88 4.56 5.28 6.07 6.90 2.03
12:12 7.15 7.78 9.13 10.59 12.16 13.84 2.89
60 < 1:12 1.03 1.12 1.32 1.53 1.76 2.00 1.09
5:12 1.43 1.56 1.83 2.12 2.43 2.77 2.01
7:12 4.35 4.73 5.55 6.44 7.39 8.41 2.42
12:12 9.12 9.93 11.66 13.52 15.52 17.66 3.57
30 15 < 1:12 1.84 2.01 2.35 2.73 3.13 3.57 1.82
5:12 2.56 2.78 3.27 3.79 4.35 4.95 2.23
7:12 3.61 3.93 4.61 5.34 6.13 6.98 2.42
12:12 5.61 6.10 7.16 8.31 9.54 10.85 2.93
30 < 1:12 1.84 2.01 2.35 2.73 3.13 3.57 1.93
5:12 2.56 2.78 3.27 3.79 4.35 4.95 2.75
7:12 4.92 5.35 6.28 7.29 8.37 9.52 3.12
12:12 8.92 9.71 11.39 13.22 15.17 17.26 4.14
45 < 1:12 1.84 2.01 2.35 2.73 3.13 3.57 2.03
5:12 2.56 2.78 3.27 3.79 4.35 4.95 3.26
7:12 6.23 6.78 7.96 9.23 10.60 12.06 3.82
12:12 12.23 13.31 15.63 18.12 20.80 23.67 5.36
60 < 1:12 1.84 2.01 2.35 2.73 3.13 3.57 2.14
5:12 2.56 2.78 3.27 3.79 4.35 4.95 3.78
7:12 7.54 8.21 9.64 11.17 12.83 14.60 4.52
12:12 15.54 16.92 19.86 23.03 26.44 30.08 6.57
60 15 < 1:12 3.42 3.72 4.36 5.06 5.81 6.61 3.63
5:12 4.75 5.17 6.06 7.03 8.07 9.19 4.40
7:12 6.76 7.36 8.64 10.02 11.51 13.09 4.75
12:12 10.35 11.27 13.23 15.34 17.61 20.04 5.71
30 < 1:12 3.42 3.72 4.36 5.06 5.81 6.61 3.83
5:12 4.75 5.17 6.06 7.03 8.07 9.19 5.37
7:12 9.12 9.93 11.66 13.52 15.52 17.66 6.07
12:12 16.30 17.75 20.83 24.16 27.73 31.55 8.00
45 < 1:12 3.55 3.87 4.54 5.27 6.05 6.88 4.03
5:12 4.94 5.37 6.31 7.31 8.40