The nominal thickness and attachment of exterior wall coverings shall be in accordance with Table R703.3(1), the wall covering material requirements of this section, and the wall covering manufacturer's installation instructions. Cladding attachment over foam sheathing shall comply with the additional requirements and limitations of Sections R703.15 through R703.17. Nominal material thicknesses in Table R703.3(1) are based on a maximum stud spacing of 16 inches (406 mm) on center. Where specified by the siding manufacturer's instructions and supported by a test report or other documentation, attachment to studs with greater spacing is permitted. Fasteners for exterior wall coverings attached to wood framing shall be in accordance with Section R703.3.2 and Table R703.3(1). Exterior wall coverings shall be attached to cold-formed steel light frame construction in accordance with the cladding manufacturer's installation instructions, the requirements of Table R703.3(1) using screw fasteners substituted for the nails specified in accordance with Table R703.3(2), or an approved design.
TABLE R703.3(1) SIDING MINIMUM ATTACHMENT AND MINIMUM THICKNESS
(continued)
TABLE R703.3(1)‒continued SIDING MINIMUM ATTACHMENT AND MINIMUM THICKNESS
TABLE R703.3(2) SCREW FASTENER SUBSTITUTION FOR SIDING ATTACHMENT TO COLD-FORMED STEEL LIGHT FRAME CONSTRUCTIONa, b, c, d, e
TABLE R703.3(1) SIDING MINIMUM ATTACHMENT AND MINIMUM THICKNESS
| SIDING MATERIAL | NOMINAL THICKNESS (inches) | JOINT TREATMENT | TYPE OF SUPPORTS FOR THE SIDING MATERIAL AND FASTENERS | ||||||
| Wood or wood structural panel sheathing into stud | Fiberboard sheathing into stud | Gypsum sheathing into stud | Foam plastic sheathing into studl | Direct to studs | Number or spacing of fasteners | ||||
| Anchored veneer: brick, concrete, masonry or stone (see Section R703.8) | 2 | Section R703.8 | Section R703.8 | ||||||
| Adhered veneer: concrete, stone or masonry (see Section R703.12) | ‒ | Section R703.12 | Section R703.12 | ||||||
| Fiber cement siding | Panel siding (see Section R703.10.1) | 5/16 | Section R703.10.1 | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) | 4d common (11/2″ × 0.099″) | 6″ panel edges 12″ inter. sup. |
| Lap siding (see Section R703.10.2) | 5/16 | Section R703.10.2 | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) | 6d common (2″ × 0.113″) or 11 gage roofing nail | Note f | |
| Hardboard panel siding (see Section R703.5) | 7/16 | ‒ | 0.120″ nail (shank) with 0.225″ head | 0.120″ nail (shank) with 0.225″ head | 0.120″ nail (shank) with 0.225″ head | 0.120″ nail (shank) with 0.225″ head | 0.120″ nail (shank) with 0.225″ head | 6″ panel edges 12″ inter. sup.d | |
| Hardboard lap siding (see Section R703.5) | 7/16 | Note e | 0.099″ nail (shank) with 0.240″ head | 0.099″ nail (shank) with 0.240″ head | 0.099″ nail (shank) with 0.240″ head | 0.099″ nail (shank) with 0.240″ head | 0.099″ nail (shank) with 0.240″ head | Same as stud spacing 2 per bearing | |
| Horizontal aluminuma | Without insulation | 0.019b | Lap | Siding nail 11/2″ × 0.120″ | Siding nail 2″ × 0.120″ | Siding nail 2″ × 0.120″ | Siding nailh 11/2″ × 0.120″ | Not allowed | Same as stud spacing |
| 0.024 | Lap | Siding nail 11/2″ × 0.120″ | Siding nail 2″ × 0.120″ | Siding nail 2″ × 0.120″ | Siding nailh 11/2″ × 0.120″ | Not allowed | |||
| With insulation | 0.019 | Lap | Siding nail 11/2″ × 0.120″ | Siding nail 21/2″ × 0.120″ | Siding nail 21/2″ × 0.120″ | Siding nailh 11/2″ × 0.120″ | Siding nail 11/2″ × 0.120″ | ||
| Insulated vinyl sidingj | 0.035 (vinyl siding layer only) | Lap | 0.120 nail (shank) with a 0.313 head or 16-gage crownh, i | 0.120 nail (shank) with a 0.313 head or 16-gage crownh | 0.120 nail (shank) with a 0.313 head or 16-gage crownh | 0.120 nail (shank) with a 0.313 head Section R703.11.2 | Not allowed | 16 inches on center or specified by manufacturer instructions, test report or other sections of this code | |
| Particleboard panels | 3/8 | ‒ | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | Not allowed | 6″ panel edges 12″ inter. sup. | |
| 1/2 | ‒ | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | |||
| 5/8 | ‒ | 6d box nail (2″ × 0.099″) | 8d box nail (21/2″ × 0.113″) | 8d box nail (21/2″ × 0.113″) | 6d box nail (2″ × 0.099″) | 6d box nail (2″ × 0.099″) | |||
| Polypropylene sidingk | Not applicable | Lap | Section 703.14.1 | Section 703.14.1 | Section 703.14.1 | Section 703.14.1 | Not allowed | As specified by the manufacturer instructions, test report or other sections of this code | |
(continued)
TABLE R703.3(1)‒continued SIDING MINIMUM ATTACHMENT AND MINIMUM THICKNESS
| SIDING MATERIAL | NOMINAL THICKNESS (inches) | JOINT TREATMENT | TYPE OF SUPPORTS FOR THE SIDING MATERIAL AND FASTENERS | ||||||
| Wood or wood structural panel sheathing into stud | Fiberboard sheathing into stud | Gypsum sheathing into stud | Foam plastic sheathing into studl | Direct to studs | Number or spacing of fasteners | ||||
| Steelc | 29 ga. | Lap | Siding nail (13/4″ × 0.113″) Staple‒13/4″ | Siding nail (23/4″ × 0.113″) Staple‒21/2″ | Siding nail (21/2″ × 0.113″) Staple‒21/4″ | Siding nail (13/4″ x 0.113″) Staple‒13/4″ | Not allowed | Same as stud spacing | |
| Vinyl siding (see Section R703.11) | 0.035 | Lap | 0.120″ nail (shank) with a 0.313″ head or 16-gage staple with 3/8- to 1/2-inch crownh, i | 0.120″ nail (shank) with a 0.313″ head or 16-gage staple with 3/8- to 1/2- inch crownh | 0.120″ nail (shank) with a 0.313″ head or 16- gage staple with 3/8- to 1/2- inch crownh | 0.120″ nail (shank) with a 0.313 head Section R703.11.2 | Not allowed | 16 inches on center or as specified by the manufacturer instructions or test report | |
| Wood siding (see Section R703.5) | Wood rustic, drop | 3/8 min. | Lap | 6d box or siding nail (2″ × 0.099″) | 6d box or siding nail (2″ × 0.099″) | 6d box or siding nail (2″ × 0.099″) | 6d box or siding nail (2″ × 0.099″) | 8d box or siding nail (21/2″ × 0.113″) 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 | |||||||
| Bevel | 7/16 | ||||||||
| Butt tip | 3/16 | Lap | |||||||
| Wood structural panel ANSI/APA PRP-210 siding (exterior grade) (see Section R703.5) | 3/8 ‒ 1/2 | Note e | 2″ × 0.099″ siding nail | 21/2″ × 0.113″ siding nail | 21/2″ × 0.113″ siding nail | 21/2″ × 0.113″ siding nail | 2″ × 0.099″ siding nail | 6″ panel edges 12″ inter. sup. | |
| Wood structural panel lap siding (see Section R703.5) | 3/8 ‒ 1/2 | Note e Note g | 2″ × 0.099″ siding nail | 21/2″ × 0.113″ siding nail | 21/2″ × 0.113″ siding nail | 21/2″ × 0.113″ siding nail | 2″ × 0.099″ siding nail | 8″ along bottom edge | |
| For SI: 1 inch = 25.4 mm. |
| a. Aluminum nails shall be used to attach aluminum siding. |
| b. Aluminum (0.019 inch) shall be unbacked only where 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. |
| c. Shall be of approved type. |
| d. Where used to resist shear forces, the spacing must be 4 inches at panel edges and 8 inches on interior supports. |
| e. Vertical end joints shall occur at studs and shall be covered with a joint cover or shall be caulked. |
| f. Face nailing: one 6d common nail through the overlapping 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 in accordance with the manufacturer's installation instructions. |
| g. Vertical joints, if staggered, shall be permitted to be away from studs if applied over wood structural panel sheathing. |
| h. Minimum fastener length must be sufficient to penetrate sheathing other nailable substrate and framing a total of a minimum of 11/4 inches or in accordance with the manufacturer's installation instructions. |
| i. Where specified by the manufacturer's instructions and supported by a test report, fasteners are permitted to penetrate into or fully through nailable sheathing or other nailable substrate of minimum thickness specified by the instructions or test report, without penetrating into framing. |
| j. Insulated vinyl siding shall comply with ASTM D 7793. |
| k. Polypropylene siding shall comply with ASTM D 7254. |
| l. Cladding attachment over foam sheathing shall comply with the additional requirements and limitations of Sections R703.15, R703.16 and R703.17. |
TABLE R703.3(2) SCREW FASTENER SUBSTITUTION FOR SIDING ATTACHMENT TO COLD-FORMED STEEL LIGHT FRAME CONSTRUCTIONa, b, c, d, e
| NAIL DIAMETER PER TABLE R703.3(1) | MINIMUM SCREW FASTENER SIZE |
| 0.099″ | No. 6 |
| 0.113″ | No. 7 |
| 0.120″ | No. 8 |
| For SI: 1 inch = 25.4 mm |
| a. Screws shall comply with ASTM C 1513 and shall penetrate a minimum of three threads through minimum 33 mil (20 gage) cold-formed steel frame construction. |
| b. Screw head diameter shall be not less than the nail head diameter required by Table R703.3(1). |
| c. Number and spacing of screw fasteners shall comply with Table R703.3(1). |
| d. Pan head, hex washer head, modified truss head or other screw head types with a flat attachment surface under the head shall be used for vinyl siding attachment. |
| e. Aluminum siding shall not be fastened directly to cold-formed steel light frame construction. |
Where the design wind pressure exceeds 30 psf or where the limits of Table R703.3.1 are exceeded, 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). For the determination of wall covering attachment, component and cladding loads shall be determined using an effective wind area of 10 square feet (0.93 m2).
TABLE R703.3.1 LIMITS FOR ATTACHMENT PER TABLE R703.3(1)
TABLE R703.3.1 LIMITS FOR ATTACHMENT PER TABLE R703.3(1)
| MAXIMUM MEAN ROOF HEIGHT | |||
| Ultimate Wind Speed (mph 3-second gust) | Exposure | ||
| B | C | D | |
| 115 | NL | 50' | 20' |
| 120 | NL | 30' | DR |
| 130 | 60' | 15' | DR |
| 140 | 35' | DR | DR |
| For SI: 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s. |
| NL = Not limited by Table R703.3.1, DR = Design required. |
Exterior wall coverings shall be securely fastened with aluminum, galvanized, stainless steel or rust-preventative coated nails or staples in accordance with Table R703.3(1) or with other approved corrosion-resistant fasteners in accordance with the wall covering manufacturer's installation instructions. Nails and staples shall comply with ASTM F1667. Nails shall be T-head, modified round head, or round head with smooth or deformed shanks. Staples shall have a minimum crown width of 7/16 inch (11.1 mm) outside diameter and be manufactured of minimum 16-gage wire. Where fiberboard, gypsum, or foam plastic sheathing backing is used, nails or staples shall be driven into the studs. 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 either the siding manufacturer's installation instructions or Table R703.3.2.
TABLE R703.3.2 OPTIONAL SIDING ATTACHMENT SCHEDULE FOR FASTENERS WHERE NO STUD PENETRATION NECESSARY
TABLE R703.3.2 OPTIONAL SIDING ATTACHMENT SCHEDULE FOR FASTENERS WHERE NO STUD PENETRATION NECESSARY
| APPLICATION | NUMBER AND TYPE OF FASTENER | SPACING OF FASTENERSb |
| Exterior wall covering (weighing 3 psf or less) attachment to wood structural panel sheathing, either direct or over foam sheathing a maximum of 2 inches thick.a Note: Does not apply to vertical siding. | Ring shank roofing nail (0.120″ min. dia.) | 12″ o.c. |
| Ring shank nail (0.148″ min. dia.) | 15″ o.c. | |
| No. 6 screw (0.138″ min. dia.) | 12″ o.c. | |
| No. 8 screw (0.164″ min. dia.) | 16″ o.c. |
| For SI: 1 inch = 25.4 mm. |
| a. Fastener length shall be sufficient to penetrate back side of the wood structural panel sheathing by at least 1/4 inch. The wood structural panel sheathing shall be not less than 7/16 inch in thickness. |
| b. Spacing of fasteners is per 12 inches of siding width. For other siding widths, multiply "Spacing of Fasteners" above by a factor of 12/s, where "s" is the siding width in inches. Fastener spacing shall never be greater than the manufacturer's minimum recommendations. |