Cladding shall be specified and installed in accordance with Section R703, the cladding manufacturer's approved instructions, including any limitations for use over foam plastic sheathing, or an approved design. In addition, the cladding or furring attachments through foam sheathing to framing shall meet or exceed the minimum fastening requirements of Section R703.15.1, Section R703.15.2, or an approved design for support of cladding weight.
Exceptions:
- Where the cladding manufacturer has provided approved installation instructions for application over foam sheathing, those requirements shall apply.
- For exterior insulation and finish systems, refer to Section R703.9.
- For anchored masonry or stone veneer installed over foam sheathing, refer to Section R703.8.
Where cladding is installed directly over foam sheathing without the use of furring, cladding minimum fastening requirements to support the cladding weight shall be as specified in Table R703.15.1.
CLADDING MINIMUM FASTENING REQUIREMENTS FOR DIRECT ATTACHMENT OVER FOAM PLASTIC SHEATHING TO SUPPORT CLADDING WEIGHTa
| CLADDING FASTENER THROUGH FOAD SHEATHING | CLADDING FASTENER TYPE AND MINIMUM SIZEb | CLADDING FASTENER VERTICAL SPACING (inches) | MAXIMUM THICKNESS OF FOAM SHEATHINGc (inches) | |||||
| 16" o.c. Fastener Horizontal Spacing | 24" o.c. Fastener Horizontal Spacing | |||||||
| Cladding Weight: | Cladding Weight: | |||||||
| 3 psf | 11 psf | 25 psf | 3 psf | 11 psf | 25 psf | |||
| Wood Framing (minimum 11/4-inch penetration) | 0.113" diameter nail | 6 | 2 | 1 | DR | 2 | 0.75 | DR |
| 8 | 2 | 1 | DR | 2 | 0.5 | DR | ||
| 12 | 2 | 0.5 | DR | 2 | DR | DR | ||
| 0.120" diameter nail | 6 | 3 | 1.5 | 0.5 | 3 | 0.75 | DR | |
| 8 | 3 | 1 | DR | 3 | 0.5 | DR | ||
| 12 | 3 | 0.5 | DR | 2 | DR | DR | ||
| 0.131" diameter nail | 6 | 4 | 2 | 0.75 | 4 | 1 | DR | |
| 8 | 4 | 1.5 | 0.5 | 4 | 0.75 | DR | ||
| 12 | 4 | 0.75 | DR | 2 | 0.5 | DR | ||
| 0.162" diameter nail | 6 | 4 | 4 | 1.5 | 4 | 2 | 1 | |
| 8 | 4 | 3 | 1 | 4 | 1.5 | 0.75 | ||
| 12 | 4 | 2 | 0.75 | 4 | 1 | DR | ||
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design required.
o.c. = on center
- Wood framing shall be Spruce-pine-fir or any wood species with a specific gravity of 0.42 or greater in accordance with AWC NDS.
- Nail fasteners shall comply with ASTM F1667, except nail length shall be permitted to exceed ASTM F1667 standard lengths.
- Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289.
Where wood furring is used to attach cladding over foam sheathing, furring minimum fastening requirements to support the cladding weight shall be as specified in Table R703.15.2. Where placed horizontally, wood furring shall be preservative-treated wood in accordance with Section R317.1 or naturally durable wood and fasteners shall be corrosion resistant in accordance Section R317.3.
FURRING MINIMUM FASTENING REQUIREMENTS FOR APPLICATION OVER FOAM PLASTIC SHEATHING TO SUPPORT CLADDING WEIGHTa, b
| FURRING MATERIAL | FRAMING MEMBER | FASTENER TYPE AND MINIMUM SIZE | MINIMUM PENETRATION INTO WALL FRAMING (inches) | FASTENER SPACING IN FURRING (inches) | MAXIMUM THICKNESS OF FOAM SHEATHINGd (inches) | |||||
| 16" o.c. Furringe | 24" o.c. Furringe | |||||||||
| Siding Weight: | Siding Weight: | |||||||||
| 3 psf | 11 psf | 25 psf | 3 psf | 11 psf | 25 psf | |||||
| Minimum 1× Wood Furringc | Minimum 2× Wood Stud | 0.131" diameter nail | 11/4 | 8 | 4 | 2 | 1 | 4 | 1.5 | DR |
| 12 | 4 | 1.5 | DR | 3 | 1 | DR | ||||
| 16 | 4 | 1 | DR | 3 | 0.5 | DR | ||||
| 0.162" diameter nail | 11/4 | 8 | 4 | 4 | 1.5 | 4 | 2 | 0.75 | ||
| 12 | 4 | 2 | 0.75 | 4 | 1.5 | DR | ||||
| 16 | 4 | 1.5 | DR | 4 | 1 | DR | ||||
| No.10 wood screw | 1 | 12 | 4 | 2 | 0.75 | 4 | 1.5 | DR | ||
| 16 | 4 | 1.5 | DR | 4 | 1 | DR | ||||
| 24 | 4 | 1 | DR | 3 | DR | DR | ||||
| 1/4" lag screw | 11/2 | 12 | 4 | 3 | 1 | 4 | 2 | 0.5 | ||
| 16 | 4 | 1.5 | DR | 4 | 1.5 | DR | ||||
| 24 | 4 | 1.5 | DR | 4 | 0.75 | DR | ||||
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design required.
o.c. = on center
- Wood framing and furring shall be Spruce-pine-fir or any wood species with a specific gravity of 0.42 or greater in accordance with AWC NDS.
- Nail fasteners shall comply with ASTM F1667, except nail length shall be permitted to exceed ASTM F1667 standard lengths.
- Where the required cladding fastener penetration into wood material exceeds 3/4 inch and is not more than 11/2 inches, a minimum 2 × wood furring or an approved design shall be used.
- Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289.
- Furring shall be spaced not more than 24 inches on center, in a vertical or horizontal orientation. In a vertical orientation, furring shall be located over wall studs and attached with the required fastener spacing. In a horizontal orientation, the indicated 8-inch and 12-inch fastener spacing in furring shall be achieved by use of two fasteners into studs at 16 inches and 24 inches on center, respectively.