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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-density requirements of Section R315.

TABLE R702.1(1)
THICKNESS OF PLASTER
PLASTER BASE FINISHED THICKNESS OF PLASTER FROM FACE OF LATH, MASONRY, CONCRETE (inches)
Gypsum plaster Portland cement mortar
Expanded metal lath 5/8, minimuma 5/8, minimuma
Wire lath 5/8, minimuma 3/4, minimum (interior)b
7/8, minimum (exterior)b
Gypsum lathg 1/2, minimum 3/4, minimum (interior)b
Masonry wallsc 1/2, minimum 1/2, minimum
Monolithic concrete wallsc,d 5/8, maximum 7/8, maximum
Monolithic concrete ceilingsc,d 3/8, maximume 1/2, maximum
Gypsum veneer basef,g 1/16, minimum 3/4, minimum (interior)b
Gypsum sheathingg 3/4, 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 portland cement plaster, weather-resistant sheathing paper complying with Section R703.2 shall be provided.
TABLE R702.1(2)
GYPSUM PLASTER PROPORTIONS
NUMBER COAT PLASTER BASE OR LATH MAXIMUM VOLUME AGGREGATE PER 100 POUNDS
NEAT PLASTERb (cubic feet)
Damp loose sanda Perlite or vermiculitec
Two-coat work Base coat Gypsum lath 2.5 2
Base coat Masonry 3 3
Three-coat work First coat Lath 2d 2
Second coat Lath 3d 2e
First and second coats Masonry 3 3
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)
PORTLAND CEMENT PLASTER
MAXIMUM VOLUME AGGREGATE PER VOLUME CEMENTITIOUS MATERIALa MINIMUM
PERIOD

MOIST COATS
MINIMUM
INTERVAL-
BETWEEN
Coat Portland cement
plasterb maximum vol-
ume aggregate per

volume cement
Portland cement-lime plasterc
Maximum volume lime per volume cement Maximum volume sand
per volume cement and
lime
Approximate minimum thicknessd curing
 (inches)
First 4 3/4 4 3/8e 48 Hoursf 48 Hoursg
Second 5 3/4 5 First and second coats 48 Hours 7 Daysh
Finish 3i - 3i 1/8 Note h
For SI: 1 inch = 25.4 mm, 1 pound = 0.454 kg.
  1. When determining the amount of aggregate in set plaster, a tolerance of 10 percent may be allowed.
  2. From 10 to 20 pounds of dry hydrated lime (or an equivalent amount of lime putty) may be added as a plasticizing agent to each sack of Type I and Type II standard portland cement in base coat plaster.
  3. No plasticizing agents shall be added.
  4. See Table R702.1(1).
  5. Measured from face of support or backing to crest of scored plaster.
  6. Twenty-four-hour minimum period for moist curing of interior portland cement plaster.
  7. Twenty-four hour minimum interval between coats of interior portland cement plaster.
  8. Finish coat plaster may be applied to interior portland cement base coats after a 48-hour period.
  9. For finish coat, plaster up to an equal part of dry hydrated lime by weight (or an equivalent volume of lime putty) may be added to Type I, Type II and Type III standard portland cement.
Gypsum plaster or portland cement plastering materials shall conform to ASTM C 5, C 28, C 35, C 37, C 59, C 61, C 587, C 588, C 631, C 847, C 897, C 933, C 1032 and C 1047, and shall be installed or applied in conformance with ASTM C 843, C 844 and C 1063. 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 (5 mm) thickness, provided the total thickness is as set forth in Table R702.1(1).
Support spacing for gypsum or metal lath on walls or ceilings shall not exceed 16 inches (406 mm) for 3/8 inch thick (10 mm) or 24 inches (610 mm) for 1/2-inch-thick (13 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 36, C 79, C 475, C 514, C 630, C 931, C 960, C 1002, C 1047, C 1177, C 1178, C 1278, C 1395 or C 1396 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.
Steel framing supporting gypsum board shall not be less than 1.25 inches (32 mm) wide in the least dimension. Light-gage nonload-bearing steel framing shall comply with ASTM C 645. Load-bearing steel framing and steel framing from 0.033 inch to 0.112 inch (1 mm to 3 mm) thick shall comply with ASTMC 955.
Foam plastics for insulating concrete form walls constructed in accordance with Sections R404.4 and R611 on the interior of habitable spaces shall be covered in accordance with Section R314.4. 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)
APPLICATION ORIENTATION 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
Nailsa Screwsb
Application without adhesive
3/8 Ceilingd Perpendicular 16 7 12 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.
Wall Either direction 16 8 16
1/2 Ceiling Either direction 16 7 12 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.
Ceilingd Perpendicular 24 7 12
Wall Either direction 24 8 12
Wall Either direction 16 8 16
5/8 Ceiling Either direction 16 7 12 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.
Ceilinge Perpendicular 24 7 12
Wall Either direction 24 8 12
Wall Either direction 16 8 16
Application with adhesive
3/8 Ceilingd Perpendicular 16 16 16 Same as above for 3/8" gypsum board
Wall Either direction 16 16 24
1/2 or 5/8 Ceiling Either direction 16 16 16 Same as above for 1/2" and 5/8" gypsum board, respectively
Ceilingd Perpendicular 24 12 16
Wall Either direction 24 16 24
Two 3/8
layers
Ceiling Perpendicular 16 16 16 Base ply nailed as above for 1/2" gypsum board; face ply installed with adhesive
Wall Either direction 24 24 24
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 Type S or W per ASTM C 1002 and shall be sufficiently long to penetrate wood framing not less than 5/8 inch and metal framing not less than 3/8 inch.
  3. Where metal 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 metal 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). Screws for attaching gypsum board to light-gage steel framing shall be Type S in accordance with ASTM C 1002 and shall penetrate the steel not less than 3/8 inch (10 mm). Screws for attaching gypsum board to steel framing 0.033 inch to 0.112 inch (1 mm to 3 mm) thick shall comply with ASTM C 954.
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 (51 mm) by 6-inch (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.) (in.)
SPACING OF FRAMING
MEMBERS (max.) (in.)
SHEAR VALUEa, b
(plf of ceiling)
MINIMUM FASTENER SIZEc, d
Gypsum Board 1/2 16 o.c. 90 5d cooler or wallboard nail; 15/8-inch
 long; 0.086-inch shank; 15/64-inch head
Gypsum Board 1/2 24 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", #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 630 or C 1178. 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 (13 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 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.
Cement, fiber-cement or glass mat gypsum backers in compliance with ASTM C 1288, C 1325 or C 1178 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 ANSI/AHA 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.
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 water that enters the assembly to the exterior. Protection against condensation in the exterior wall assembly shall be provided in accordance with Chapter 11 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 Section R703.2 and Section 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. 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. Exterior wall envelope test assemblies shall be at least 4 feet (1219 mm) by 8 feet (2438 mm) in size.
    3. Exterior wall assemblies shall be tested at a minimum differential pressure of 6.24 pounds per square foot (299 Pa).
    4. Exterior wall envelope assemblies shall be subjected to a minimum test exposure duration 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.
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). Where joints occur, felt shall be lapped not less than 6 inches (152 mm). The felt or other approved material shall be continuous to the top of walls 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 weather-resistive sheathing paper.
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 lapped a minimum of 1 inch (25 mm), or 0.5 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 per Figure R301.2(4) 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 MATERIAL NOMINAL
THICKNESa

(inches)
JOINT
TREATMENT
WATER-
RESISTIVE
BARRIER
REQUIRED
TYPE OF SUPPORTS FOR THE SIDING MATERIAL AND FASTENERSb,c,d
Wood or wood
structural
panel

sheathing
Fiberboard sheathing into stud Gypsum sheathing into stud Foam
plastic sheathing into stud
Direct to studs Number or
spacing of fasteners
Horizontal aluminume Without insulation 0.019f Lap Yes 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
0.024 Lap Yes 0.120 nail
11/2" long
0.120 nail
2" long
0.120 nail
2" long
0.120 naily Not allowed  
With
insulation
0.019 Lap Yes 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
 
Brick veneerz
Concrete masonry veneerz
2
2
Section R703 Yes
(Note l)
See Section R703 and Figure R703.7g
Hardboardk
Panel siding-vertical
7/16 Yes Note n Note n Note n Note n Note n 6" panel edges
12" inter. sup.o
Hardboardk
Lap-siding-horizontal
7/16 Note q Yes Note p Note Note p Note p Note p Same as stud spacing
2 per bearing
Steelh 29 ga. Lap Yes 0.113 nail
13/4"
Staple-13/4"
0.113 nail 23/4"
Staple-21/2"
0.113 nail
21/2" Staple-21/4"
0.113 naily Stapley Not allowed Same as stud
spacing
Stone veneer 2 Section R703 Yes
(Note l)
See Section R703 and Figure R703.7g
Particleboard panels 3/8 1/2 Yes 6d box nail
(2" × 0.099")
6d box nail (2"× 0.099") 6d box nail (2" × 0.099") box naily 6d box nail (2" × 0.099"), 3/8 not allowed 6" panel edge,
5/8 Yes 6d box nail
(2" × 0.099")
8d box nail (21/2" × 0.113") 8d box nail (21/2" × 0.113") box naily 6d box nail (2" × 0.099") 12" inter. sup.
Plywood paneli
(exterior grade)
3/8 Yes 0.099 nail-2" 0.113 nail-21/2" 0.099 nail-2" 0.113 naily 0.099 nail-2" 6" on edges,
12" inter. sup.
Vinyl sidingm 0.035 Lap Yes 0.120 nail 11/2" Staple-13/4" 0.120 nail 2" Staple-21/2" 0.120 nail 2" Staple-21/2" 0.120 naily Stapley Not allowed Same as stud spacing
Woodj rustic, drop 3/8 Min Lap Yes Fastener 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
Shiplap 19/32 Average Lap Yes
Bevel 7/16
Butt tip 3/16 Lap Yes
Fiber cement panel sidingr 5/16 Note s Yes
Note x
6d corrosion-resistant nailt 6d corrosion-resistant nailt 6d corrosion-resistant nailt 6d corrosion-resistant nailt, y 4d corrosion-resistant nailu 6" o.c. on edges, 12" o.c. on intermed. studs
Fiber cement lap
sidingr
5/16 Note v Yes Note x 6d corrosion-resistant nailt 6d corrosion-resistant nailt 6d corrosion-resistant nailt 6d corrosion-resistant nailt, y 6d corrosion-resistant nailw Note w
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 for fiberboard or gypsum backing.
  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. A weather-resistive membrane shall be installed weatherboard fashion under the vertical siding unless the siding boards are lapped or battens are used.
  11. Hardboard siding shall comply with AHA A135.6.
  12. For masonry veneer, a weather-resistive sheathing paper is not required over a sheathing that performs as a weather-resistive barrier when a 1-inch air space is provided between the veneer and the sheathing. When the 1-inch space is filled with mortar, a weather-resistive sheathing paper is required over studs or sheathing.
  13. Vinyl siding shall comply with ASTM D 3679.
  14. 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.
  15. When used to resist shear forces, the spacing must be 4 inches at panel edges and 8 inches on interior supports.
  16. 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.
  17. Vertical end joints shall occur at studs and shall be covered with a joint cover or shall be caulked.
  18. Fiber cement siding shall comply with the requirements of ASTM C 1186.
  19. See Section R703.10.1.
  20. Minimum 0.102" smooth shank, 0.255" round head.
  21. Minimum 0.099" smooth shank, 0.250" round head.
  22. See Section R703.10.2.
  23. Face nailing: 2 nails at each stud. Concealed nailing: one 11 gage 11/2 galv. roofing nail (0.371" head diameter, 0.120" shank) or 6d galv. box nail at each stud.
  24. See Section R703.2 exceptions.
  25. Minimum nail length must accommodate sheathing and penetrate framing 11/2 inches.
  26. Adhered masonry veneer shall comply with the requirements in Sections 6.1 and 6.3 of ACI 530/ASCE 5/TMS-402.
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 (51mm) 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    
16 71/2 12b
18 81/2 14c
24 111/2 16
Shakesa    
18 81/2 14
24 111/2 18
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 the 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 11/2-inch-long (38 mm), 11 gage nails having a 7/16-inch (11.1 mm) head, or 7/8-inch-long (22.2 mm), 16 gage staples, spaced at no more than 6 inches (152 mm), or as otherwise approved.
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 R319.1 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.

The proportion of aggregate to cementitious materials shall be as set forth in Table R702.1(3).
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 926. 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 a water-resistive vapor-permeable barrier with a performance at least equivalent to two layers of Grade D paper.
Exception: Where the water-resistive barrier that is applied over wood-based sheathing has a water resistance equal to or greater than that of 60 minute Grade D paper and is separated from the stucco by an intervening, substantially nonwater-absorbing layer or designed drainage space.
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 and shall not exceed 5 inches (127 mm) in thickness.
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. Wall bracing at exterior and interior braced wall lines shall be in accordance with Section R602.10 or R603.7, and the additional requirements of Table R703.7(1).
  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. Wall bracing and hold downs at exterior and interior braced wall lines shall be in accordance with Sections R602.10 and R602.11 and the additional requirements of Table R703.7(2). In Seismic Design Categories D0, D1 and D2, cripple walls shall not be permitted, and required interior braced wall lines shall be supported on continuous foundations.


For SI: 1 inch = 25.4 mm.
FIGURE R703.7
MASONRY VENEER WALL DETAILS
(continued)



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 Sections R703.7.4.2 and R703.7.4.3.
  4. See Section R703.7.3.
FIGURE R703.7—continued
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 CATEGORY NUMBER 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 MINIMUM SHEATHING AMOUNT
(percent of braced wall line length)c
A or B Steel: 1 or 2 Wood: 1, 2 or 3 30 5 50 all Table R602.10.1 or Table R603.7
C 1 30 5 50 1 only Table R602.10.1 or Table R603.7
2 30 5 50 top Table R602.10.1 or Table R603.7
bottom 1.5 times length required by Table R602.10.1 or 1.5 times length required by Table R603.7
Wood only: 3 30 5 50 top Table R602.10.1
middle 1.5 times length required by Table R602.10.1
bottom 1.5 times length required by Table R602.10.1
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.
  3. Applies to exterior and interior braced wall lines.
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 WOOD FRAMED STORY MINIMUM SHEATHING AMOUNT
(percent of
braced wall
line length)c
MINIMUM SHEATHING THICKNESS AND FASTENING SINGLE STORY HOLD DOWN FORCE (lb)d CUMULATIVE HOLD DOWN FORCE (lb)e
D0 1 20f 4 40 1 only 35 7/16-inch wood
structural panel
sheathing with
8d common
nails spaced at 4
inches on center
at panel edges,
12 inches on
center at
intermediate
supports. 8d
common nails at
4 inches on
center at braced
wall panel end
posts with hold
down attached.
N/A
2 20f 4 40 top 35 1900
bottom 45 3200 5100
3 30g 4 40 top 40 1900
middle 45 3500 5400
bottom 60 3500 8900
D1 1 20f 4 40 1 only 45 2100
2 20f 4 40 top 45 2100
bottom 45 3700 5800
3 20f 4 40 top 45 2100
middle 45 3700 5800
bottom 60 3700 9500
D2 1 20f 3 30 1 only 55 2300
2 20f 3 30 top 55 2300
bottom 55 3900 6200
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. Applies to exterior and interior braced wall lines.
  4. Hold down force is minimum allowable stress design load for connector providing uplift tie from wall framing at end of braced wall panel at the noted story to wall framing at end of braced wall panel at the story below, or to foundation or foundation wall. Use single story hold down force where edges of braced wall panels do not align; a continuous load path to the foundation shall be maintained. [See Figure R703.7(1)(b)].
  5. Where hold down connectors from stories above align with stories below, use cumulative hold down force to size middle and bottom story hold down connectors. [See Figure R703.7(1)(a)].
  6. 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.
  7. 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.

FIGURE R703.7(1)
HOLD DOWNS AT EXTERIOR AND INTERIOR BRACED WALL PANELS WHEN USING STONE OR MASONRY VENEER
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 × 3 inch × 1/4 inch (76 mm × 76 mm × 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 × 3 inch × 1/4 inch (76 mm × 76 mm × 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 and the allowable span shall not exceed the value set forth in Table R703.7.3. The lintels shall have a length of bearing not less than 4 inches (102 mm).
Masonry veneer shall be anchored to the supporting wall with corrosion-resistant metal ties. Where veneer is anchored to wood backings by corrugated sheet metal ties, the distance separating the veneer from the sheathing material shall be a maximum of a nominal 1 inch (25 mm). Where the veneer is anchored to wood backings using metal strand wire ties, the distance separating the veneer from the sheathing material shall be a maximum of 41/2 inches (114 mm). Where the veneer is anchored to cold-formed steel backings, adjustable metal strand wire ties shall be used. Where veneer is anchored to cold-formed steel backings, the distance separating the veneer from the sheathing material shall be a maximum of 41/2 inches (114 mm).
Veneer ties, if strand wire, shall not be less in thickness than No. 9 U.S. gage [(0.148 in.) (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 in.)(0.76 mm)] 7/8-inch (22 mm) corrugated. Each tie shall be spaced not more than 24 inches (610 mm) on center horizontally and vertically and shall support not more than 2.67 square feet (0.25 m2) of wall area.
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.
Veneer ties around wall openings. 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).
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 air space is filled with mortar, a water-resistive barrier is required over studs or sheathing. When filling the air space, replacing the sheathing and water-resistive barrier with a wire mesh and approved water-resistive barrier or an approved water-resistive barrier-backed reinforcement attached directly to the studs is permitted.
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 to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashings shall be installed at all of the following locations:
  1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage.
  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.
All Exterior Insulation Finish Systems (EIFS) shall be installed in accordance with the manufacturer's installation instructions and the requirements of this section. Decorative trim shall not be face nailed through the EIFS. The EIFS shall terminate not less than 6 inches (152 mm) above the finished ground level.
All EIFS shall have a water-resistive barrier applied between the underlying water-sensitive building components and the exterior insulation, and a means of draining water to the exterior of the veneer. A water-resistive barrier shall be compliant with ASTM D 226 Type I asphalt saturated felt or equivalent, shall be applied horizontally with the upper layer lapped over the lower layer not less than 2 inches (51 mm), and shall have all vertical joints lapped not less than 6 inches (152 mm).
Flashing of EIFS shall be provided in accordance with the requirements of Section R703.8.
Panels shall be installed with the long dimension parallel to framing. Vertical joints shall occur over framing members and shall be sealed with caulking or covered with battens. Horizontal joints shall be flashed with Z-flashing and blocked with solid wood framing.
Lap siding shall be lapped a minimum of 11/4 inches (32 mm) and shall have the ends sealed with caulking, covered with an H-section joint cover, or located over a strip of flashing. Lap siding courses may be installed with the fastener heads exposed or concealed, according to 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.