CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2012 (IRC 2012)

Copyright

Minnesota Department of Labor and Industry

Important Disclaimer

Preface

Effective Use of the International Residential Code

Chapter 1 Scope and Administration

2015 Minnesota Building Code Administration

2015 Minnesota Provisions to the Minnesota State Building Code (Including Radon)

Minnesota Rules, Chapter 1309

Chapter 2 Definitions

Chapter 3 Building Planning

Chapter 4 Foundations

Chapter 5 Floors

Chapter 6 Wall Construction

Chapter 7 Wall Covering

Chapter 8 Roof-Ceiling Construction

Chapter 9 Roof Assemblies

Chapter 10 Chimneys and Fireplaces

Chapter 11 [Re] Energy Efficiency

Chapter 12 Mechanical Administration

Chapter 25 Plumbing Administration

Section P2904 Dwelling Unit Fire Sprinkler Systems

Chapter 34 General Requirements

Chapter 44 Referenced Standards

Appendix K Sound Transmission

Appendix L Permit Fees

The provisions of this chapter shall control the design and construction of the interior and exterior wall covering for all buildings.

Products sensitive to adverse weather shall not be installed until adequate weather protection for the installation is provided. Exterior sheathing shall be dry before applying exterior cover.

Interior coverings or wall finishes shall be installed in accordance with this chapter and Table R702.1(1), Table R702.1(2), Table R702.1(3) and Table R702.3.5. Interior masonry veneer shall comply with the requirements of Section R703.7.1 for support and Section R703.7.4 for anchorage, except an air space is not required. Interior finishes and materials shall conform to the flame spread and smoke-development requirements of Section R302.9.

TABLE R702.1(1)

THICKNESS OF PLASTER

PLASTER BASEFINISHED THICKNESS OF PLASTER FROM FACE OF LATH, MASONRY, CONCRETE (inches)
Gypsum PlasterCement Plaster
Expanded metal lath5/8, minimuma5/8, minimuma
Wire lath5/8, minimuma3/4, minimum (interior)b
7/8, minimum (exterior)b
Gypsum lathg1/2, minimum3/4, minimum (interior)b
Masonry wallsc1/2, minimum1/2, minimum
Monolithic concrete wallsc, d5/8, maximum7/8, maximum
Monolithic concrete ceilingsc, d3/8, maximume1/2, maximum
Gypsum veneer basef, g1/16, minimum3/4, minimum (interior)b
Gypsum sheathingg3/4, minimum (interior)b
7/8, minimum (exterior)b

For SI: 1 inch = 25.4 mm.

  1. When measured from back plane of expanded metal lath, exclusive of ribs, or self-furring lath, plaster thickness shall be 3/4 inch minimum.
  2. When measured from face of support or backing.
  3. Because masonry and concrete surfaces may vary in plane, thickness of plaster need not be uniform.
  4. When applied over a liquid bonding agent, finish coat may be applied directly to concrete surface.
  5. Approved acoustical plaster may be applied directly to concrete or over base coat plaster, beyond the maximum plaster thickness shown.
  6. Attachment shall be in accordance with Table R702.3.5.
  7. Where gypsum board is used as a base for cement plaster, a water-resistive barrier complying with Section R703.2 shall be provided.

TABLE R702.1(2)

GYPSUM PLASTER PROPORTIONSa

NUMBERCOATPLASTER BASE OR LATHMAXIMUM VOLUME AGGREGATE PER 100 POUNDS NEAT PLASTERb
(cubic feet)
Damp Loose SandaPerlite or Vermiculitec
Two-coat workBase coatGypsum lath2.52
Base coatMasonry33
Three-coat workFirst coatLath2d2
Second coatLath3d2e
First and second coatsMasonry33

For SI: 1 inch = 25.4 mm, 1 cubic foot = 0.0283 m3, 1 pound = 0.454 kg.

  1. Wood-fibered gypsum plaster may be mixed in the proportions of 100 pounds of gypsum to not more than 1 cubic foot of sand where applied on masonry or concrete.
  2. When determining the amount of aggregate in set plaster, a tolerance of 10 percent shall be allowed.
  3. Combinations of sand and lightweight aggregate may be used, provided the volume and weight relationship of the combined aggregate to gypsum plaster is maintained.
  4. If used for both first and second coats, the volume of aggregate may be 2.5 cubic feet.
  5. Where plaster is 1 inch or more in total thickness, the proportions for the second coat may be increased to 3 cubic feet.

TABLE R702.1(3)

CEMENT PLASTER PROPORTIONS, PARTS BY VOLUME

COAT
CEMENT
PLASTER
TYPE
CEMENTITIOUS MATERIALSVOLUME OF
AGGREGATE PER
SUM OF SEPARATE
VOLUMES OF
CEMENTITIOUS
MATERIALSb
Portland Cement
Type I, II or III or
Blended Cement
Type IP, I (PM), IS or
I (SM)
Plastic
Cement
Masonry Cement
Type M, S or N
Lime
FirstPortland or blended13/4 - 11/2a21/2 - 4
Masonry1 21/2 - 4
Plastic121/2 - 4
SecondPortland or blended13/4 - 11/2 3 - 5
Masonry13 - 5
Plastic13 - 5
FinishPortland or blended13/4 - 211/2 - 3
Masonry111/2 - 3
Plastic111/2 - 3

For SI: 1 inch = 25.4 mm, 1 pound = 0.545 kg.

  1. Lime by volume of 0 to 3/4 shall be used when the plaster will be placed over low-absorption surfaces such as dense clay tile or brick.
  2. The same or greater sand proportion shall be used in the second coat than used in the first coat.
Gypsum plaster materials shall conform to ASTM C 5, C 22, C 28, C 35, C 59, C 61, C 587, C 631, C 847, C 933, C 1032 and C 1047, and shall be installed or applied in compliance with ASTM C 843 and C 844. Gypsum lath or gypsum base for veneer plaster shall conform to ASTM C 1396. Plaster shall not be less than three coats when applied over metal lath and not less than two coats when applied over other bases permitted by this section, except that veneer plaster may be applied in one coat not to exceed 3/16 inch (4.76 mm) thickness, provided the total thickness is in accordance with Table R702.1(1).
Cement plaster materials shall conform to ASTM C 91 (Type M, S or N), C 150 (Type I, II and III), C 595 [Type IP, I (PM), IS and I (SM), C 847, C 897, C 926, C 933, C 1032, C 1047 and C 1328, and shall be installed or applied in compliance with ASTM C 1063. Gypsum lath shall conform to ASTM C 1396. Plaster shall not be less than three coats when applied over metal lath and not less than two coats when applied over other bases permitted by this section, except that veneer plaster may be applied in one coat not to exceed 3/16 inch (4.76 mm) thickness, provided the total thickness is in accordance with Table R702.1(1).

Each coat shall be kept in a moist condition for at least 24 hours prior to application of the next coat.

Exception: Applications installed in accordance with ASTM C 926.

The finish coat for two-coat cement plaster shall not be applied sooner than 48 hours after application of the first coat. For three coat cement plaster the second coat shall not be applied sooner than 24 hours after application of the first coat. The finish coat for three-coat cement plaster shall not be applied sooner than 48 hours after application of the second coat.
Support spacing for gypsum or metal lath on walls or ceilings shall not exceed 16 inches (406 mm) for 3/8-inch-thick (9.5 mm) or 24 inches (610 mm) for 1/2-inch-thick (12.7 mm) plain gypsum lath. Gypsum lath shall be installed at right angles to support framing with end joints in adjacent courses staggered by at least one framing space.
All gypsum board materials and accessories shall conform to ASTM C 22, C 475, C 514, C 1002, C 1047, C 1177, C 1178, C 1278, C 1396 or C 1658 and shall be installed in accordance with the provisions of this section. Adhesives for the installation of gypsum board shall conform to ASTM C 557.
Wood framing supporting gypsum board shall not be less than 2 inches (51 mm) nominal thickness in the least dimension except that wood furring strips not less than 1-inch by 2-inch (25 mm by 51 mm) nominal dimension may be used over solid backing or framing spaced not more than 24 inches (610 mm) on center.
Cold-formed steel framing supporting gypsum board shall not be less than 11/4 inches (32 mm) wide in the least dimension. Nonload-bearing cold-formed steel framing shall comply with ASTM C 645. Load-bearing cold-formed steel framing and all cold-formed steel framing from 0.033 inch to 0.112 inch (1 mm to 3 mm) thick shall comply with ASTM C 955.
Foam plastics for insulating concrete form walls constructed in accordance with Sections R404.1.2 and R611 on the interior of habitable spaces shall be protected in accordance with Section R316.4. Use of adhesives in conjunction with mechanical fasteners is permitted. Adhesives used for interior and exterior finishes shall be compatible with the insulating form materials.

Maximum spacing of supports and the size and spacing of fasteners used to attach gypsum board shall comply with Table R702.3.5. Gypsum sheathing shall be attached to exterior walls in accordance with Table R602.3(1). Gypsum board shall be applied at right angles or parallel to framing members. All edges and ends of gypsum board shall occur on the framing members, except those edges and ends that are perpendicular to the framing members. Interior gypsum board shall not be installed where it is directly exposed to the weather or to water.

TABLE R702.3.5

MINIMUM THICKNESS AND APPLICATION OF GYPSUM BOARD

THICKNESS
OF GYPSUM
BOARD
(inches)
APPLICATIONORIENTATION OF
GYPSUM BOARD
TO FRAMING
MAXIMUM SPACING
OF FRAMING
MEMBERS
(inches o.c.)
MAXIMUM SPACING
OF FASTENERS (inches)
SIZE OF NAILS FOR APPLICATION
TO WOOD FRAMINGc
NailsaScrewsb
Application without adhesive
3/8CeilingdPerpendicular16712
13 gage, 11/4″ long, 19/64″ head; 0.098″ diameter,
11/4″ long, annular-ringed; or 4d cooler nail,
0.080″ diameter, 13/8″ long, 7/32″ head.
WallEither direction16816
1/2CeilingEither direction16712
13 gage, 13/8″ long, 19/64″ head; 0.098″ diameter,
11/4″ long, annular-ringed; 5d cooler nail, 0.086″
diameter, 15/8″ long, 15/64″ head; or gypsum board
nail, 0.086? diameter, 15/8″ long, 9/32″ head.
CeilingdPerpendicular24712
WallEither direction24812
WallEither direction16816
5/8CeilingEither direction16712
13 gage, 15/8″ long, 19/64″ head; 0.098″ diameter,
13/8″ long, annular-ringed; 6d cooler nail, 0.092″
diameter, 17/8″ long, 1/4″ head; or gypsum board nail,
0.0915″ diameter, 17/8″ long, 19/64″ head.
CeilingePerpendicular24712
WallEither direction24812
WallEither direction16816
Application with adhesive
3/8CeilingdPerpendicular161616Same as above for 3/8″ gypsum board
WallEither direction161624
1/2 or 5/8CeilingEither direction161616
Same as above for 1/2″ and 5/8″ gypsum board,
respectively
CeilingdPerpendicular241216
WallEither direction241624
Two
3/8 layers
CeilingPerpendicular161616
Base ply nailed as above for 1/2″ gypsum board;
face ply installed with adhesive
WallEither direction242424

For SI: 1 inch = 25.4 mm.

  1. For application without adhesive, a pair of nails spaced not less than 2 inches apart or more than 21/2 inches apart may be used with the pair of nails spaced 12 inches on center.
  2. Screws shall be in accordance with Section R702.3.6. Screws for attaching gypsum board to structural insulated panels shall penetrate the wood structural panel facing not less than 7/16 inch.
  3. Where cold-formed steel framing is used with a clinching design to receive nails by two edges of metal, the nails shall be not less than 5/8 inch longer than the gypsum board thickness and shall have ringed shanks. Where the cold-formed steel framing has a nailing groove formed to receive the nails, the nails shall have barbed shanks or be 5d, 131/2 gage, 15/8 inches long, 15/64-inch head for 1/2-inch gypsum board; and 6d, 13 gage, 17/8 inches long, 15/64-inch head for 5/8-inch gypsum board.
  4. Three-eighths-inch-thick single-ply gypsum board shall not be used on a ceiling where a water-based textured finish is to be applied, or where it will be required to support insulation above a ceiling. On ceiling applications to receive a water-based texture material, either hand or spray applied, the gypsum board shall be applied perpendicular to framing. When applying a water-based texture material, the minimum gypsum board thickness shall be increased from 3/8 inch to 1/2 inch for 16-inch on center framing, and from 1/2 inch to 5/8 inch for 24-inch on center framing or 1/2-inch sag-resistant gypsum ceiling board shall be used.
  5. Type X gypsum board for garage ceilings beneath habitable rooms shall be installed perpendicular to the ceiling framing and shall be fastened at maximum 6 inches o.c. by minimum 17/8 inches 6d coated nails or equivalent drywall screws.
Screws for attaching gypsum board to wood framing shall be Type W or Type S in accordance with ASTM C 1002 and shall penetrate the wood not less than 5/8 inch (16 mm). Gypsum board shall be attached to cold-formed steel framing with minimum No. 6 screws. Screws for attaching gypsum board to cold-formed steel framing less than 0.033 inch (1 mm) thick shall be Type S in accordance with ASTM C 1002 or bugle head style in accordance with ASTM C 1513 and shall penetrate the steel not less than 3/8 inch (9.5 mm). Screws for attaching gypsum board to cold-formed steel framing 0.033 inch to 0.112 inch (1 mm to 3 mm) thick shall be in accordance with ASTM C 954 or bugle head style in accordance with ASTM C 1513. Screws for attaching gypsum board to structural insulated panels shall penetrate the wood structural panel facing not less than 7/16 inch (11 mm).

Use of gypsum board shall be permitted on wood joists to create a horizontal diaphragm in accordance with Table R702.3.7. Gypsum board shall be installed perpendicular to ceiling framing members. End joints of adjacent courses of board shall not occur on the same joist. The maximum allowable diaphragm proportions shall be 11/2:1 between shear resisting elements. Rotation or cantilever conditions shall not be permitted. Gypsum board shall not be used in diaphragm ceilings to resist lateral forces imposed by masonry or concrete construction. All perimeter edges shall be blocked using wood members not less than 2-inch by 6-inch (51 mm by 152 mm) nominal dimension. Blocking material shall be installed flat over the top plate of the wall to provide a nailing surface not less than 2 inches (51 mm) in width for the attachment of the gypsum board.

TABLE R702.3.7

SHEAR CAPACITY FOR HORIZONTAL WOOD-FRAMED GYPSUM BOARD DIAPHRAGM CEILING ASSEMBLIES

MATERIAL
THICKNESS OF MATERIAL
(min.) (inch)
SPACING OF
FRAMING MEMBERS
(max.) (inch)
SHEAR VALUEa, b
(plf of ceiling)
MINIMUM
FASTENER SIZEc, d
Gypsum board1/216 o.c.90
5d cooler or wallboard nail;
15/8-inch long; 0.086-inch shank;
15/64-inch head
Gypsum board1/224 o.c.70
5d cooler or wallboard nail;
15/8-inch long; 0.086-inch shank;
15/64-inch head

For SI: 1 inch = 25.4 mm, 1 pound per linear foot = 1.488 kg/m.

  1. Values are not cumulative with other horizontal diaphragm values and are for short-term loading caused by wind or seismic loading. Values shall be reduced 25 percent for normal loading.
  2. Values shall be reduced 50 percent in Seismic Design Categories D0, D1, D2 and E.
  3. 11/4-inch, #6 Type S or W screws may be substituted for the listed nails.
  4. Fasteners shall be spaced not more than 7 inches on center at all supports, including perimeter blocking, and not less than 3/8 inch from the edges and ends of the gypsum board.
Gypsum board used as the base or backer for adhesive application of ceramic tile or other required nonabsorbent finish material shall conform to ASTM C 1396, C 1178 or C1278. Use of water-resistant gypsum backing board shall be permitted on ceilings where framing spacing does not exceed 12 inches (305 mm) on center for 1/2-inch-thick (12.7 mm) or 16 inches (406 mm) for 5/8-inch-thick (16 mm) gypsum board. Water-resistant gypsum board shall not be installed over a Class I or II vapor retarder in a shower or tub compartment. Cut or exposed edges, including those at wall intersections, shall be sealed as recommended by the manufacturer.
Water resistant gypsum backing board shall not be used where there will be direct exposure to water, or in areas subject to continuous high humidity.
Ceramic tile surfaces shall be installed in accordance with ANSI A108.1, A108.4, A108.5, A108.6, A108.11, A118.1, A118.3, A136.1 and A137.1.
Fiber-cement, fiber-mat reinforced cementitious backer units, glass mat gypsum backers or fiber-reinforced gypsum backers in compliance with ASTM C 1288, C 1325, C 1178 or C 1278, respectively, and installed in accordance with manufacturers’ recommendations shall be used as backers for wall tile in tub and shower areas and wall panels in shower areas.
Wood veneer paneling and hardboard paneling shall be placed on wood or cold-formed steel framing spaced not more than 16 inches (406 mm) on center. Wood veneer and hard board paneling less than 1/4-inch (6 mm) nominal thickness shall not have less than a 3/8-inch (10 mm) gypsum board backer. Wood veneer paneling not less than 1/4-inch (6 mm) nominal thickness shall conform to ANSI/HPVA HP-1. Hardboard paneling shall conform to CPA/ANSI A135.5.
Wood shakes and shingles shall conform to CSSB Grading Rules for Wood Shakes and Shingles and shall be permitted to be installed directly to the studs with maximum 24 inches (610 mm) on-center spacing.
Nails, staples or glue are permitted for attaching shakes or shingles to the wall, and attachment of the shakes or shingles directly to the surface shall be permitted provided the fasteners are appropriate for the type of wall surface material. When nails or staples are used, two fasteners shall be provided and shall be placed so that they are covered by the course above.
Where furring strips are used, they shall be 1 inch by 2 inches or 1 inch by 3 inches (25 mm by 51 mm or 25 mm by 76 mm), spaced a distance on center equal to the desired exposure, and shall be attached to the wall by nailing through other wall material into the studs.

A Class I or II vapor retarder is required on the interior side of frame walls in Climate Zones 6 and 7. Class II vapor retarders are permitted only when specified on the construction documents.

Class III vapor retarders shall be permitted where any one of the conditions in Table R702.7.1 is met.

TABLE R702.7.1

CLASS III VAPOR RETARDERS

CLIMATE
ZONE
CLASS III VAPOR RETARDERS PERMITTED FOR:a
Marine
4
Vented cladding over wood structural panels.
Vented cladding over fiberboard.
Vented cladding over gypsum.
Insulated sheathing with R-value ≥ 2.5 over 2 × 4 wall.
Insulated sheathing with R-value ≥ 3.75 over 2 × 6 wall.
5Vented cladding over wood structural panels.
Vented cladding over fiberboard.
Vented cladding over gypsum.
Insulated sheathing with R-value ≥ 5 over 2 × 4 wall.
Insulated sheathing with R-value ≥ 7.5 over 2 × 6 wall.
6Vented cladding over fiberboard.
Vented cladding over gypsum.
Insulated sheathing with R-value ≥ 7.5 over 2 × 4 wall.
Insulated sheathing with R-value ≥ 11.25 over 2 × 6 wall.
7 and 8Insulated sheathing with R-value ≥ 10 over 2 × 4 wall.
Insulated sheathing with R-value ≥ 15 over 2 × 6 wall.

For SI: 1 pound per cubic foot = 16 kg/m3.

  1. Spray foam with a minimum density of 2 lb/ft3 applied to the interior cavity side of wood structural panels, fiberboard, insulating sheathing or gypsum is deemed to meet the insulating sheathing requirement where the spray foam R-value meets or exceeds the specified insulating sheathing R-value.

The vapor retarder class shall be based on the manufacturer’s certified testing or a tested assembly.

The following shall be deemed to meet the class specified:

    Class I: Sheet polyethylene, unperforated aluminum foil.

    Class II: Kraft-faced fiberglass batts.

    Class III: Latex or enamel paint.

For the purposes of this section, vented cladding shall include the following minimum clear air spaces. Other openings with the equivalent vent area shall be permitted.

  1. Vinyl lap or horizontal aluminum siding applied over a weather resistive barrier as specified in Table R703.4.
  2. Brick veneer with a clear airspace as specified in Table R703.7.4.
  3. Other approved vented claddings.
Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.8.

The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the exterior veneer as required by Section R703.2 and a means of draining to the exterior water that enters the assembly. Protection against condensation in the exterior wall assembly shall be provided in accordance with Section R702.7 of this code.

Exceptions:

  1. A weather-resistant exterior wall envelope shall not be required over concrete or masonry walls designed in accordance with Chapter 6 and flashed according to Section R703.7 or R703.8.
  2. Compliance with the requirements for a means of drainage, and the requirements of Sections R703.2 and R703.8, shall not be required for an exterior wall envelope that has been demonstrated to resist wind-driven rain through testing of the exterior wall envelope, including joints, penetrations and intersections with dissimilar materials, in accordance with ASTM E 331 under the following conditions:

    1. 2.1. Exterior wall envelope test assemblies shall include at least one opening, one control joint, one wall/eave interface and one wall sill. All tested openings and penetrations shall be representative of the intended end-use configuration.
    2. 2.2. Exterior wall envelope test assemblies shall be at least 4 feet by 8 feet (1219 mm by 2438 mm) in size.
    3. 2.3. Exterior wall assemblies shall be tested at a minimum differential pressure of 6.24 pounds per square foot (299 Pa).
    4. 2.4. Exterior wall envelope assemblies shall be subjected to the minimum test exposure for a minimum of 2 hours.

The exterior wall envelope design shall be considered to resist wind-driven rain where the results of testing indicate that water did not penetrate control joints in the exterior wall envelope, joints at the perimeter of openings penetration or intersections of terminations with dissimilar materials.

Wall coverings, backing materials and their attachments shall be capable of resisting wind loads in accordance with Tables R301.2(2) and R301.2(3). Wind-pressure resistance of the siding and backing materials shall be determined by ASTM E 330 or other applicable standard test methods. Where wind-pressure resistance is determined by design analysis, data from approved design standards and analysis conforming to generally accepted engineering practice shall be used to evaluate the siding and backing material and its fastening. All applicable failure modes including bending rupture of siding, fastener withdrawal and fastener head pull-through shall be considered in the testing or design analysis. Where the wall covering and the backing material resist wind load as an assembly, use of the design capacity of the assembly shall be permitted.

One layer of No. 15 asphalt felt, free from holes and breaks, complying with ASTM D 226 for Type 1 felt or other approved water-resistive barrier shall be applied over studs or sheathing of all exterior walls. Such felt or material shall be applied horizontally, with the upper layer lapped over the lower layer not less than 2 inches (51 mm). The water-resistive barrier shall overlap the flashings required in Section R703.8 not less than 2 inches (51 mm). Where joints occur in the water-resistive barrier or flashing, the joints shall be lapped not less than 6 inches (152 mm). The felt or other approved material shall be continuous up to the underside of the rafter or truss top chord and terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as described in Section R703.1.

Exception: Omission of the water-resistive barrier is permitted in the following situations:

  1. In detached accessory buildings.
  2. Under exterior wall finish materials as permitted in Table R703.4.
  3. Under paperbacked stucco lath when the paper backing is an approved water-resistive barrier.
Joints in wood, hardboard or wood structural panel siding shall be made as follows unless otherwise approved. Vertical joints in panel siding shall occur over framing members, unless wood or wood structural panel sheathing is used, and shall be shiplapped or covered with a batten. Horizontal joints in panel siding shall be lapped a minimum of 1 inch (25 mm) or shall be shiplapped or shall be flashed with Z-flashing and occur over solid blocking, wood or wood structural panel sheathing.
Horizontal lap siding shall be installed in accordance with the manufacturer’s recommendations. Where there are no recommendations the siding shall be lapped a minimum of 1 inch (25 mm), or 1/2 inch (13 mm) if rabbeted, and shall have the ends caulked, covered with a batten or sealed and installed over a strip of flashing.

Unless specified otherwise, all wall coverings shall be securely fastened in accordance with Table R703.4 or with other approved aluminum, stainless steel, zinc-coated or other approved corrosion-resistive fasteners. Where the basic wind speed in accordance with Figure R301.2(4)A is 110 miles per hour (49 m/s) or higher, the attachment of wall coverings shall be designed to resist the component and cladding loads specified in Table R301.2(2), adjusted for height and exposure in accordance with Table R301.2(3).

TABLE R703.4

WEATHER-RESISTANT SIDING ATTACHMENT AND MINIMUM THICKNESS

SIDING MATERIALNOMINAL
THICKNESSa
(inches)
JOINT TREATMENTWATER-
RESISTIVE
BARRIER
REQUIRED
TYPE OF SUPPORTS FOR THE SIDING MATERIAL AND FASTENERSb, c, d
Wood or wood
structural
panel
sheathing into stud
Fiberboard
sheathing
into stud
Gypsum
sheathing
into stud
Foam
plastic
sheathing
into stud
Direct to
studs
Number or
spacing of
fasteners
Horizonal
aluminume
Without
insulation
0.019f
0.024
LapYes
0.120
nail 11/2″ long
0.120
nail 2″ long
0.120
nail 2″ long
0.120
naily
Not
allowed
Same as stud
spacing
LapYes
0.120
nail 11/2″ long
0.120
nail 2″ long
0.120
nail 2″ long
0.120
naily
Not allowed
With
insulation
0.019LapYes
0.120
nail 11/2″ long
0.120
nail 21/2″ long
0.120
nail 21/2″ long
0.120
naily
0.120
nail 11/2″ long
Anchored veneer:
brick, concrete,
masonry or stone
2Section R703YesSee Section R703 and Figure R703.7g
Adhered veneer: concrete, stone or masonrywSection R703Yes Note wSee Section R703.6.1g or in accordance with the manufacturer’s instructions.
Hardboardk Panel siding-vertical7/16YesNote mNote mNote mNote mNote m
6″ panel edges
12″ inter. sup.n
Hardboardk
Lap-siding-horizontal
7/16Note pYesNote oNote oNote oNote oNote oSame as stud
spacing 2 per
bearing
Steelh29 ga.LapYes0.113 nail
13/4″ Staple
-13/4
0.113 nail
23/4″ Staple
-21/2
0.113 nail 21/2″ Staple
-21/4
0.113 nailv StaplevNot allowedSame as stud spacing
Particleboard panels3/8 - 1/2Yes
6d box nail
(2″ × 0.099″)
6d box nail
(2″ × 0.099″)
6d box nail
(2″ × 0.099″)
box nailv
6d box nail
(2″ ×
0.099″),
3/8 not allowed
6″ panel edge,
12" inter. sup.
5/8Yes
6d box nail
(2″ × 0.099″)
8d box nail
(21/2″ × 0.113″)
8d box nail
(21/2″ × 0.113″)
box nailv
6d box nail
(2″" × 0.099″)
Wood structural paneli
ANSI/APA-PRP 210 sidingi (exterior grade)
3/8 - 1/2Note pYes0.099 nail-2″0.113 nail-21/20.113 nail-21/20.113 nailv0.099 nail-2″6″ panel edges, 12″ inter. sup.
Wood structural panel
lapsiding
3/8 - 1/2Note p Note xYes0.099 nail-2″0.113 nail-21/20.113 nail-21/20.113 nailx0.099 nail-2″8″ along bottom edge
Vinyl sidingl0.035LapYes
0.120 nail
(shank)
with a 0.313
head or
16-gage
staple with
3/8 to1/2-inch
crowny, z
0.120 nail
(shank)
with a 0.313
head or 16-gage
staple with
3/8 to 1/2
-inch crowny
0.120 nail
(shank)
with a 0.313
head or
16-gage
staple with
3/8 to 1/2-inch
crowny
0.120 nail
(shank)
with a
0.313
head per
Section R703.11.2
Not
allowed
16 inches on
center or
specified by the
manufacturer
instructions
or test report
Woodj rustic, drop3/8 MinLapYesFastener penetration into stud-1″
0.113
nail-21/2
Staple-2″
Face nailing up
to 6″ widths,
1 nail per bearing;
8″ widths and
over, 2 nails
per bearing
Shiplap19/32 AverageLapYesFastener penetration into stud-1″
0.113
nail-21/2
Staple-2″
Face nailing
up to 6″
widths, 1
nail per
bearing; 8″
widths and
over, 2 nails
per bearing
Bevel7/16
Butt tip3/16LapYes
Fiber cement
panel sidingq
5/16Note qYes Note u
6d common
corrosion- resistant nailr
6d common
corrosion- resistant
nailr
6d common
corrosion- resistant
nailr
6d common
corrosion- resistant nailr, v
4d common
corrosion-resistant
nailr
6″ o.c.
on edges, 12″ o.c.
on intermed. studs
Fiber cement
lap sidings
5/16Note sYes Note u
6d common
corrosion-
resistant nailr
6d common
corrosion-
resistant nailr
6d common
corrosion-
resistant nailr
6d common
corrosion-
resistant nailr, v
6d common
corrosion-
resistant nail or 11- gage roofing nailr
Note t

For SI: 1 inch = 25.4 mm.

  1. Based on stud spacing of 16 inches on center where studs are spaced 24 inches, siding shall be applied to sheathing approved for that spacing.
  2. Nail is a general description and shall be T-head, modified round head, or round head with smooth or deformed shanks.
  3. Staples shall have a minimum crown width of 7/16-inch outside diameter and be manufactured of minimum 16-gage wire.
  4. Nails or staples shall be aluminum, galvanized, or rust-preventative coated and shall be driven into the studs where fiberboard, gypsum, or foam plastic sheathing backing is used. Where wood or wood structural panel sheathing is used, fasteners shall be driven into studs unless otherwise permitted to be driven into sheathing in accordance with the siding manufacturer’s installation instructions.
  5. Aluminum nails shall be used to attach aluminum siding.
  6. Aluminum (0.019 inch) shall be unbacked only when the maximum panel width is 10 inches and the maximum flat area is 8 inches. The tolerance for aluminum siding shall be +0.002 inch of the nominal dimension.
  7. All attachments shall be coated with a corrosion-resistant coating.
  8. Shall be of approved type.
  9. Three-eighths-inch plywood shall not be applied directly to studs spaced more than 16 inches on center when long dimension is parallel to studs. Plywood 1/2-inch or thinner shall not be applied directly to studs spaced more than 24 inches on center. The stud spacing shall not exceed the panel span rating provided by the manufacturer unless the panels are installed with the face grain perpendicular to the studs or over sheathing approved for that stud spacing.
  10. Wood board sidings applied vertically shall be nailed to horizontal nailing strips or blocking set 24 inches on center. Nails shall penetrate 11/2 inches into studs, studs and wood sheathing combined or blocking.
  11. Hardboard siding shall comply with CPA/ANSI A135.6.
  12. Vinyl siding shall comply with ASTM D 3679.
  13. Minimum shank diameter of 0.092 inch, minimum head diameter of 0.225 inch, and nail length must accommodate sheathing and penetrate framing 11/2 inches.
  14. When used to resist shear forces, the spacing must be 4 inches at panel edges and 8 inches on interior supports.
  15. Minimum shank diameter of 0.099 inch, minimum head diameter of 0.240 inch, and nail length must accommodate sheathing and penetrate framing 11/2 inches.
  16. Vertical end joints shall occur at studs and shall be covered with a joint cover or shall be caulked.
  17. See Section R703.10.1.
  18. Fasteners shall comply with the nominal dimensions in ASTM F 1667.
  19. See Section R703.10.2.
  20. Face nailing: one 6d common nail through the over lap ping planks at each stud. Concealed nailing: one 11 gage 11/2 inch long galv. roofing nail through the top edge of each plank at each stud.
  21. See Section R703.2 exceptions.
  22. Minimum nail length must accommodate sheathing and penetrate framing 11/2 inches.
  23. Adhered masonry veneer shall comply with the requirements of Section R703.6.3 and shall comply with the requirements in Sections 6.1 and 6.3 of TMS-402 ACI 530/ASCE 5.
  24. Vertical joints, if staggered shall be permitted to be away from studs if applied over wood structural panel sheathing.
  25. Minimum fastener length must accommodate sheathing and penetrate framing 0.75 inches or in accordance with the manufacturer’s installation instructions.
  26. Where approved by the manufacturer’s instructions or test report siding shall be permitted to be installed with fasteners penetrating not less than 0.75 inches through wood or wood structural sheathing with or without penetration into the framing.
Wood shakes and shingles shall conform to CSSB Grading Rules for Wood Shakes and Shingles.
Wood shakes or shingles shall be applied either single-course or double-course over nominal 1/2-inch (13 mm) wood-based sheathing or to furring strips over 1/2-inch (13 mm) nominal nonwood sheathing. A permeable water-resistive barrier shall be provided over all sheathing, with horizontal overlaps in the membrane of not less than 2 inches (51 mm) and vertical overlaps of not less than 6 inches (152 mm). Where furring strips are used, they shall be 1 inch by 3 inches or 1 inch by 4 inches (25 mm by 76 mm or 25 mm by 102 mm) and shall be fastened horizontally to the studs with 7d or 8d box nails and shall be spaced a distance on center equal to the actual weather exposure of the shakes or shingles, not to exceed the maximum exposure specified in Table R703.5.2. The spacing between adjacent shingles to allow for expansion shall not exceed 1/4 inch (6 mm), and between adjacent shakes, it shall not exceed 1/2 inch (13 mm). The offset spacing between joints in adjacent courses shall be a minimum of 11/2 inches (38 mm).

The maximum weather exposure for shakes and shingles shall not exceed that specified in Table R703.5.2.

TABLE R703.5.2

MAXIMUM WEATHER EXPOSURE FOR WOOD SHAKES AND SHINGLES ON EXTERIOR WALLSa, b, c (Dimensions are in inches)

LENGTH
EXPOSURE FOR
SINGLE COURSE
EXPOSURE FOR
DOUBLE COURSE
Shinglesa
1671/212b
1881/214c
24111/216
Shakesa
1881/214
24111/218

For SI: 1 inch = 25.4 mm.

  1. Dimensions given are for No. 1 grade.
  2. A maximum 10-inch exposure is permitted for No. 2 grade.
  3. A maximum 11-inch exposure is permitted for No. 2 grade.
Each shake or shingle shall be held in place by two hot-dipped zinc-coated, stainless steel, or aluminum nails or staples. The fasteners shall be long enough to penetrate the sheathing or furring strips by a minimum of 1/2 inch (13 mm) and shall not be overdriven.
Staples shall not be less than 16 gage and shall have a crown width of not less than 7/16 inch (11 mm), and the crown of the staples shall be parallel with the butt of the shake or shingle. In single-course application, the fasteners shall be concealed by the course above and shall be driven approximately 1 inch (25 mm) above the butt line of the succeeding course and 3/4 inch (19 mm) from the edge. In double-course applications, the exposed shake or shingle shall be face-nailed with two casing nails, driven approximately 2 inches (51 mm) above the butt line and 3/4 inch (19 mm) from each edge. In all applications, staples shall be concealed by the course above. With shingles wider than 8 inches (203 mm) two additional nails shall be required and shall be nailed approximately 1 inch (25 mm) apart near the center of the shingle.
The bottom courses shall be doubled.
Installation of these materials shall be in compliance with ASTM C 926 and ASTM C 1063 and provisions of this code.
All lath and lath attachments shall be of corrosion-resistant materials. Expanded metal or woven wire lath shall be attached with 11 gage nails having a 7/16-inch (11.1 mm) head or 16 gage staples, spaced at no more than 6 inches (152 mm) or as otherwise approved. Nails or staples shall penetrate wood framing support members not less than 3/4-inch (19 mm).
Provisions for the control of expansion shall be determined by the exterior plaster application designer. ASTM C 1063 Sections 7.11.4 - 7.11.4.4 do not apply.

Plastering with portland cement plaster shall be not less than three coats when applied over metal lath or wire lath and shall be not less than two coats when applied over masonry, concrete, pressure-preservative treated wood, or decay-resistant wood as specified in Section R317.1 or gypsum backing. If the plaster surface is completely covered by veneer or other facing material or is completely concealed, plaster application need be only two coats, provided the total thickness is as set forth in Table R702.1(1).

On wood-frame construction with an on-grade floor slab system, exterior plaster shall be applied to cover, but not extend below, lath, paper, and screed.

A minimum 0.019-inch (0.5 mm) (No. 26 galvanized sheet gage), corrosion-resistant weep screed or plastic weep screed, with a minimum vertical attachment flange of 31/2 inches (89 mm) shall be provided at or below the foundation plate line on exterior stud walls in accordance with ASTM C 1063. The weep screed shall be placed a minimum of 4 inches (102 mm) above the earth or 2 inches (51 mm) above paved areas and shall be of a type that will allow trapped water to drain to the exterior of the building. The weather-resistant barrier shall lap the attachment flange. The exterior lath shall cover and terminate on the attachment flange of the weep screed.

Water-resistive barriers shall be installed as required in Section R703.2 and, where applied over wood-based sheathing, shall include two layers of a water-resistive vapor-permeable barrier. Each layer shall meet both of the following requirements:

  1. A water resistance of not less than that of 60-minute Grade D paper; or a minimum hydrostatic head of 2331/32 inches (60.9 cm) when tested in accordance with hydrostatic pressure test method AATCC 127-2008; or a minimum water transudation time of 60 minutes when tested in accordance with ASTM D-779.
  2. A water vapor permeance of not less than that of No. 15 felt; or a minimum permeance rating of 8.5 gr/h.ft.2 in Hg (US perm) (4.9 ×1010kg/Pasm2) when tested in accordance with Procedure B of ASTM E96.
  3. Exception: One layer of water-resistive barrier complying with R703.2 is permitted when a drainage space that allows bulk water to flow freely behind the cladding is provided.

Each coat shall be kept in a moist condition for at least 48 hours prior to application of the next coat.

Exception: Applications installed in accordance with ASTM C 926. The second coat is permitted to be applied as soon as the first coat has attained sufficient rigidity to receive the second coat.

The finish coat for two-coat cement plaster shall not be applied sooner than seven days after application of the first coat. For three-coat cement plaster, the second coat shall not be applied sooner than 48 hours after application of the first coat, except as required in Section R703.6.4. The finish coat for three-coat cement plaster shall not be applied sooner than seven days after application of the second coat.

Stone and masonry veneer shall be installed in accordance with this chapter, Table R703.4 and Figure R703.7. These veneers installed over a backing of wood or cold-formed steel shall be limited to the first story above-grade plane and shall not exceed 5 inches (127 mm) in thickness. See Section R602.10 for wall bracing requirements for masonry veneer for wood-framed construction and Section R603.9.5 for wall bracing requirements for masonry veneer for cold-formed steel construction.

Exceptions:

  1. For all buildings in Seismic Design Categories A, B and C, exterior stone or masonry veneer, as specified in Table R703.7(1), with a backing of wood or steel framing shall be permitted to the height specified in Table R703.7(1) above a noncombustible foundation.
  2. For detached one- or two-family dwellings in Seismic Design Categories D0, D1 and D2, exterior stone or masonry veneer, as specified in Table R703.7(2), with a backing of wood framing shall be permitted to the height specified in Table R703.7(2) above a noncombustible foundation.
For SI: 1 inch = 24.5 mm.

For SI: 1 inch = 25.4 mm.

  1. See Sections R703.7.5, R703.7.6 and R703.8.
  2. See Sections R703.2 and R703.7.4.
  3. See Section R703.7.4.2 and Table R703.7.4.
  4. See Section R703.7.3.

FIGURE R703.7

MASONRY VENEER WALL DETAILS

TABLE R703.7(1)

STONE OR MASONRY VENEER LIMITATIONS AND REQUIREMENTS, WOOD OR STEEL FRAMING, SEISMIC DESIGN CATEGORIES A, B AND C

SEISMIC DESIGN CATEGORYNUMBER OF
WOOD OR STEEL-
FRAMED STORIES
MAXIMUM HEIGHT OF
VENEER ABOVE
NONCOMBUSTIBLE
FOUNDATIONa (feet)
MAXIMUM NOMINAL
THICKNESS OF
VENEER (inches)
MAXIMUM WEIGHT OF
VENEER (psf)b
WOOD OR STEEL-
FRAMED STORY
A or BSteel: 1 or 2 Wood: 1, 2 or 330550all
C1305501 only
230550top
bottom
Wood only: 330550top
middle
bottom

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.479 kPa.

  1. An additional 8 feet is permitted for gable end walls. See also story height limitations of Section R301.3.
  2. Maximum weight is installed weight and includes weight of mortar, grout, lath and other materials used for installation. Where veneer is placed on both faces of a wall, the combined weight shall not exceed that specified in this table.

TABLE R703.7(2)

STONE OR MASONRY VENEER LIMITATIONS AND REQUIREMENTS, ONE- AND TWO-FAMILY DETACHED DWELLINGS, WOOD FRAMING, SEISMIC DESIGN CATEGORIES D0, D1 AND D2

SEISMIC DESIGN
CATEGORY
NUMBER OF WOOD
FRAMED STORIESa
MAXIMUM HEIGHT OF
VENEER ABOVE
NONCOMBUSTIBLE
FOUNDATION OR
FOUNDATION WALL (feet)
MAXIMUM NOMINAL
THICKNESS OF VENEER
(inches)
MAXIMUM WEIGHT OF
VENEER (psf)b
D0120c440
220c440
330d440
D1120c440
220c440
320c440
D2120c330
220c330

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.479 kPa, 1 pound-force = 4.448 N.

  1. Cripple walls are not permitted in Seismic Design Categories D0, D1 and D2.
  2. Maximum weight is installed weight and includes weight of mortar, grout and lath, and other materials used for installation.
  3. The veneer shall not exceed 20 feet in height above a noncombustible foundation, with an additional 8 feet permitted for gable end walls, or 30 feet in height with an additional 8 feet for gable end walls where the lower 10 feet has a backing of concrete or masonry wall. See also story height limitations of Section R301.3.
  4. The veneer shall not exceed 30 feet in height above a noncombustible foundation, with an additional 8 feet permitted for gable end walls. See also story height limitations of Section R301.3.
Veneers used as interior wall finishes shall be permitted to be supported on wood or cold-formed steel floors that are designed to support the loads imposed.
Except in Seismic Design Categories D0, D1 and D2, exterior masonry veneers having an installed weight of 40 pounds per square foot (195 kg/m2) or less shall be permitted to be supported on wood or cold-formed steel construction. When masonry veneer supported by wood or cold-formed steel construction adjoins masonry veneer supported by the foundation, there shall be a movement joint between the veneer supported by the wood or cold-formed steel construction and the veneer supported by the foundation. The wood or cold-formed steel construction supporting the masonry veneer shall be designed to limit the deflection to 1/600 of the span for the supporting members. The design of the wood or cold-formed steel construction shall consider the weight of the veneer and any other loads.

A minimum 6 inches by 4 inches by 5/16 inch (152 mm by 102 mm by 8 mm) steel angle, with the long leg placed vertically, shall be anchored to double 2 inches by 4 inches (51 mm by 102 mm) wood studs at a maximum on-center spacing of 16 inches (406 mm). Anchorage of the steel angle at every double stud spacing shall be a minimum of two 7/16 inch (11 mm) diameter by 4 inch (102 mm) lag screws. The steel angle shall have a minimum clearance to underlying construction of 1/16 inch (2 mm). A minimum of two-thirds the width of the masonry veneer thickness shall bear on the steel angle. Flashing and weep holes shall be located in the masonry veneer wythe in accordance with Figure R703.7.2.1. The maximum height of masonry veneer above the steel angle support shall be 12 feet, 8 inches (3861 mm). The air space separating the masonry veneer from the wood backing shall be in accordance with Sections R703.7.4 and R703.7.4.2. The method of support for the masonry veneer on wood construction shall be constructed in accordance with Figure R703.7.2.1.

The maximum slope of the roof construction without stops shall be 7:12. Roof construction with slopes greater than 7:12 but not more than 12:12 shall have stops of a minimum 3 inch by 3 inch by 1/4 inch (76 mm by 76 mm by 6 mm) steel plate welded to the angle at 24 inches (610 mm) on center along the angle or as approved by the building official.

FIGURE R703.7.2.1

EXTERIOR MASONRY VENEER SUPPORT BY STEEL ANGLES

A steel angle shall be placed directly on top of the roof construction. The roof supporting construction for the steel angle shall consist of a minimum of three 2 inch by 6 inch (51 mm by 152 mm) wood members. The wood member abutting the vertical wall stud construction shall be anchored with a minimum of three 5/8-inch (16 mm) diameter by 5-inch (127 mm) lag screws to every wood stud spacing. Each additional roof member shall be anchored by the use of two 10d nails at every wood stud spacing. A minimum of two-thirds the width of the masonry veneer thickness shall bear on the steel angle. Flashing and weep holes shall be located in the masonry veneer wythe in accordance with Figure R703.7.2.2. The maximum height of the masonry veneer above the steel angle support shall be 12 feet, 8 inches (3861 mm). The air space separating the masonry veneer from the wood backing shall be in accordance with Sections R703.7.4 and R703.7.4.2. The support for the masonry veneer on wood construction shall be constructed in accordance with Figure R703.7.2.2.

The maximum slope of the roof construction without stops shall be 7:12. Roof construction with slopes greater than 7:12 but not more than 12:12 shall have stops of a minimum 3 inch by 3 inch by 1/4 inch (76 mm by 76 mm by 6 mm) steel plate welded to the angle at 24 inches (610 mm) on center along the angle or as approved by the building official.

FIGURE R703.7.2.2

EXTERIOR MASONRY VENEER SUPPORT BY ROOF MEMBERS

Masonry veneer shall not support any vertical load other than the dead load of the veneer above. Veneer above openings shall be supported on lintels of noncombustible materials. The lintels shall have a length of bearing not less than 4 inches (102 mm). Steel lintels shall be shop coated with a rust-inhibitive paint, except for lintels made of corrosion-resistant steel or steel treated with coatings to provide corrosion resistance. Construction of openings shall comply with either Section R703.7.3.1 or 703.7.3.2.

The allowable span shall not exceed the values set forth in Table R703.7.3.1.

TABLE R703.7.3.1

ALLOWABLE SPANS FOR LINTELS SUPPORTING MASONRY VENEERa, b, c, d

SIZE OF STEEL ANGLEa, c, d
(inches)
NO STORY ABOVEONE STORY ABOVETWO STORIES ABOVENO. OF 1/2-INCH OR EQUIVALENT
REINFORCING BARS IN
REINFORCED LINTELb, d
3 × 3 × 1/46'-0″4'-6″3'-0″1
4 × 3 × 1/48'-0″6'-0″4'-6″1
5 × 31/2 × 5/1610'-0″8'-0″6'-0″2
6 × 31/2 × 5/1614'-0″9'-6″7'-0″2
2-6 × 31/2 × 5/1620'-0″12'-0″9'-6″4

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

  1. Long leg of the angle shall be placed in a vertical position.
  2. Depth of reinforced lintels shall not be less than 8 inches and all cells of hollow masonry lintels shall be grouted solid. Reinforcing bars shall extend not less than 8 inches into the support.
  3. Steel members indicated are adequate typical examples; other steel members meeting structural design requirements may be used.
  4. Either steel angle or reinforced lintel shall span opening.

The allowable span shall not exceed 18 feet 3 inches (5562 mm) and shall be constructed to comply with Figure R703.7.3.2 and the following:

  1. Provide a minimum length of 18 inches (457 mm) of masonry veneer on each side of opening as shown in Figure R703.7.3.2.
  2. Provide a minimum 5-inch by 31/2-inch by 5/16-inch (127 mm by 89 mm by 7.9 mm) steel angle above the opening and shore for a minimum of 7 days after installation.
  3. Provide double-wire joint reinforcement extending 12 inches (305 mm) beyond each side of the opening. Lap splices of joint reinforcement a minimum of 12 inches (305 mm). Comply with one of the following:

    1. 3.1. Double-wire joint reinforcement shall be 3/16-inch (4.8 mm) diameter and shall be placed in the first two bed joints above the opening.
    2. 3.2. Double-wire joint reinforcement shall be 9 gauge (0.144 inch or 3.66 mm diameter) and shall be placed in the first three bed joints above the opening.
  4. Provide the height of masonry veneer above opening, in accordance with Table R703.7.3.2.

TABLE R703.7.3.2

HEIGHT OF MASONRY VENEER ABOVE OPENING

MINIMUM HEIGHT OF MASONRY
VENEER ABOVE OPENING (INCH)
MAXIMUM HEIGHT OF MASONRY
VENEER ABOVE OPENING (FEET)
13< 5
245 to < 12
60
12 to height above support
allowed by Section R703.7

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

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

FIGURE R703.7.3.2

MASONRY VENEER OPENING

Masonry veneer shall be anchored to the supporting wall studs with corrosion-resistant metal ties embedded in mortar or grout and extending into the veneer a minimum of 11/2 inches (38 mm), with not less than 5/8-inch (15.9 mm) mortar or grout cover to outside face. Masonry veneer shall conform to Table R703.7.4.

TABLE R703.7.4

TIE ATTACHMENT AND AIR SPACE REQUIREMENTS

BACKING AND TIEMINIMUM TIEMINIMUM TIE FASTENERaAIR SPACE
Wood stud backing with corrugated sheet metal22 U.S. gage (0.0299 in.) × 7/8 in. wide8d common nail b (21/2 in. × 0.131 in.)Nominal 1 in. between sheathing and veneer
Wood stud backing with metal strand wireW1.7 (No. 9 U.S. gage; 0.148 in.) with hook embedded in mortar joint8d common nail b (21/2 in. × 0.131 in.)Minimum nominal 1 in. between sheathing and veneerMaximum 41/2 in. between backing and veneer
Cold-formed steel stud backing with adjustable metal strand wireW1.7 (No. 9 U.S. gage; 0.148 in.) with hook embedded in mortar jointNo. 10 screw extending through the steel framing a minimum of three exposed threadsMinimum nominal 1 in. between sheathing and veneerMaximum 41/2 in. between backing and veneer

For SI: 1 inch = 25.4 mm.

  1. In Seismic Design Category D0, D1 or D2, the minimum tie fastener shall be an 8d ring-shank nail (21/2 in. × 0.131 in.) or a No. 10 screw extending through the steel framing a minimum of three exposed threads.
  2. All fasteners shall have rust-inhibitive coating suitable for the installation in which they are being used, or be manufactured from material not susceptible to corrosion.

Veneer ties, if strand wire, shall not be less in thickness than No. 9 U.S. gage [(0.148 inch) (4 mm)] wire and shall have a hook embedded in the mortar joint, or if sheet metal, shall be not less than No. 22 U.S. gage by [(0.0299 inch) (0.76 mm)] 7/8 inch (22 mm) corrugated. Each tie shall support not more than 2.67 square feet (0.25 m2) of wall area and shall be spaced not more than 32 inches (813 mm) on center horizontally and 24 inches (635 mm) on center vertically.

Exception: In Seismic Design Category D0, D1 or D2 or townhouses in Seismic Design Category C or in wind areas of more than 30 pounds per square foot pressure (1.44 kPa), each tie shall support not more than 2 square feet (0.2 m2) of wall area.

Additional metal ties shall be provided around all wall openings greater than 16 inches (406 mm) in either dimension. Metal ties around the perimeter of openings shall be spaced not more than 3 feet (9144 mm) on center and placed within 12 inches (305 mm) of the wall opening.

The veneer shall be separated from the sheathing by an air space of a minimum of a nominal 1 inch (25 mm) but not more than 41/2 inches (114 mm).

Exception: One layer of water-resistive barrier complying with Section R703.2 is permitted when a drainage space that allows bulk water to flow freely behind the cladding is provided.

As an alternate to the air space required by Section R703.7.4.2, mortar or grout shall be permitted to fill the air space. When the 1-inch (25.4 mm) space is filled with mortar, a weather-resistant membrane or building paper as described in Section R703.2 or R703.6.3 is required over studs or sheathing. When filling the air space, it is permitted to replace the sheathing and weather-resistant membrane or asphalt-saturated felt paper with a wire mesh and approved paper or an approved paper-backed reinforcement attached directly to the studs.
On sheathed substrates, a corrosion-resistant, self-furring expanded metal lath shall be installed over the weather-resistant membrane or building paper with appropriate fasteners as described in Section R703.6.1. Fasteners shall penetrate wood supports a minimum of one inch (25.4 mm).
Flashing shall be located beneath the first course of masonry above finished ground level above the foundation wall or slab and at other points of support, including structural floors, shelf angles and lintels when masonry veneers are designed in accordance with Section R703.7. See Section R703.8 for additional requirements.
Weepholes shall be provided in the outside wythe of masonry walls at a maximum spacing of 33 inches (838 mm) on center. Weepholes shall not be less than 3/16 inch (5 mm) in diameter. Weepholes shall be located immediately above the flashing.

Approved corrosion-resistant flashing shall be applied shingle-fashion in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. Self-adhered membranes used as flashing shall comply with AAMA 711. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashing shall be installed at all of the following locations:

  1. Exterior window and door openings. Flashing shall be installed at the head and sides of exterior window and door openings and shall extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage. Flashing at exterior window and door openings shall be installed in accordance with at least one of the following:

    1. the fenestration manufacturer’s installation and flashing instructions. When flashing is not addressed in the fenestration manufacturer’s instructions, it shall be installed in accordance with the flashing manufacturer’s instructions;
    2. in accordance with the flashing design or method of a registered design professional; and
    3. in accordance with other approved methods.
  2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.
  3. Under and at the ends of masonry, wood, or metal copings and sills.
  4. Continuously above all projecting wood trim.
  5. Where exterior porches, decks, or stairs attach to a wall or floor assembly of wood-frame construction.
  6. At wall and roof intersections.
  7. At built-in gutters.
  8. Where exterior material meets in other than a vertical line.
  9. Where the lower portion of a sloped roof stops within the plane of an intersecting wall cladding in such a manner as to divert water away from the assembly in compliance with Section R903.2.1.
  10. At the intersection of the foundation and rim joist framing when the exterior wall covering does not lap the foundation insulation.

Pan flashing shall be installed in accordance with the fenestration manufacturer’s installation and flashing instructions. Where flashing instructions or details are not provided, pan flashing shall be installed at the sill of exterior window and door openings. Pan flashing shall be sealed or sloped in such a manner as to direct water to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage.

Exceptions:

  1. Windows or doors installed in accordance with the manufacturer’s installation instructions which include an alternate flashing method.
  2. Windows or doors in detached accessory structures.
  3. Skylights, bow or bay windows.
  4. Doors required to meet accessibility requirements that would prevent the installation of pan flashing.
  5. Repairs or replacement of existing windows and doors.
  6. When a method is provided by a registered design professional.
Exterior Insulation and Finish System (EIFS) shall comply with this chapter and Sections R703.9.1 and R703.9.3. EIFS with drainage shall comply with this chapter and Sections R703.9.2, R703.9.3 and R703.9.4.
EIFS shall comply with ASTM E 2568.
EIFS with drainage shall comply with ASTM E 2568 and shall have an average minimum drainage efficiency of 90 percent when tested in accordance with ASTM E 2273.
The water-resistive barrier shall comply with Section R703.2 or ASTM E 2570.
The water-resistive barrier shall be applied between the EIFS and the wall sheathing.
Flashing of EIFS shall be provided in accordance with the requirements of Section R703.8.
All EIFS shall be installed in accordance with the manufacturer’s installation instructions and the requirements of this section.
The EIFS shall terminate not less than 6 inches (152 mm) above the finished ground level.
Decorative trim shall not be face nailed though the EIFS.
Fiber-cement panels shall comply with the requirements of ASTM C 1186, Type A, minimum Grade II. Panels shall be installed with the long dimension either parallel or perpendicular to framing. Vertical and horizontal joints shall occur over framing members and shall be sealed with caulking, covered with battens or shall be designed to comply with Section R703.1. Panel siding shall be installed with fasteners according to Table R703.4 or approved manufacturer’s installation instructions.
Fiber-cement lap siding having a maximum width of 12 inches shall comply with the requirements of ASTM C 1186, Type A, minimum Grade II. Lap siding shall be lapped a minimum of 11/4 inches (32 mm) and lap siding not having tongue-and-groove end joints shall have the ends sealed with caulking, installed with an H-section joint cover, located over a strip of flashing or shall be designed to comply with Section R703.1. Lap siding courses may be installed with the fastener heads exposed or concealed, according to Table R703.4 or approved manufacturers’ installation instructions.
Vinyl siding shall be certified and labeled as conforming to the requirements of ASTM D 3679 by an approved quality control agency.
Vinyl siding, soffit and accessories shall be installed in accordance with the manufacturer’s installation instructions.
Soffit panels shall be individually fastened to a supporting component such as a nailing strip, fascia or subfascia component or as specified by the manufacturer’s instructions.

Vinyl siding used with foam plastic sheathing shall be installed in accordance with Section R703.11.2.1, R703.11.2.2, or R703.11.2.3.

Exception: Where the foam plastic sheathing is applied directly over wood structural panels, fiberboard, gypsum sheathing or other approved backing capable of independently resisting the design wind pressure, the vinyl siding shall be installed in accordance with Section R703.11.1.

Where the basic wind speed does not exceed 90 miles per hour (40 m/s), the Exposure Category is B and gypsum wall board or equivalent is installed on the side of the wall opposite the foam plastic sheathing, the minimum siding fastener penetration into wood framing shall be 11/4 inches (32 mm) using minimum 0.120-inch diameter nail (shank) with a minimum 0.313-inch diameter head, 16 inches on center. The foam plastic sheathing shall be minimum 1/2-inch-thick (12.7 mm) (nominal) extruded polystyrene per ASTM C 578, 1/2-inch-thick (12.7 mm) (nominal) polyisocyanurate per ASTM C 1289, or 1-inch-thick (25 mm) (nominal) expanded polystyrene per ASTM C 578.

Where the basic wind speed exceeds 90 miles per hour (40 m/s) or the Exposure Category is C or D, or all conditions of Section R703.11.2.1 are not met, the adjusted design pressure rating for the assembly shall meet or exceed the loads listed in Tables R301.2(2) adjusted for height and exposure using Table R301.2(3). The design wind pressure rating of the vinyl siding for installation over solid sheathing as provided in the vinyl siding manufacturer’s product specifications shall be adjusted for the following wall assembly conditions:

  1. For wall assemblies with foam plastic sheathing on the exterior side and gypsum wall board or equivalent on the interior side of the wall, the vinyl siding's design wind pressure rating shall be multiplied by 0.39.
  2. For wall assemblies with foam plastic sheathing on the exterior side and no gypsum wall board or equivalent on the interior side of wall, the vinyl siding's design wind pressure rating shall be multiplied by 0.27.
Where the vinyl siding manufacturer’s product specifications provide an approved design wind pressure rating for installation over foam plastic sheathing, use of this design wind pressure rating shall be permitted and the siding shall be installed in accordance with the manufacturer’s installation instructions.
Adhered masonry veneer shall be installed in accordance with the manufacturer’s instructions.

On exterior stud walls, adhered masonry veneer shall be installed:

  1. Minimum of 4 inches (102 mm) above the earth;
  2. Minimum of 2 inches (51 mm) above paved areas; or
  3. Minimum of 1/2 inch (12 mm) above exterior walking surfaces which are supported by the same foundation that supports the exterior wall.
A corrosion-resistant screed or flashing of a minimum 0.019-inch (0.48 mm) or 26-gage galvanized or plastic with a minimum vertical attachment flange of 31/2 inches (89 mm) shall be installed to extend a minimum of 1 inch (25 mm) below the foundation plate line on exterior stud walls in accordance with Section R703.8. The water-resistive barrier, as required by Table R703.4, Footnote w, shall lap over the exterior of the attachment flange of the screed or flashing.
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