2603.12.2 Furred cladding attachment.
BC § 2603.12.2
Where steel or 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 2603.12.2. Where placed horizontally, wood furring shall be preservative-treated wood in accordance with Section 2303.1.9 or naturally durable wood and fasteners shall be corrosion resistant in accordance Section 2304.10.5. Steel furring shall have a minimum G60 galvanized coating. Table 2603.12.2Furring Minimum Fastening Requirements for Application over Foam Plastic Sheathing to Support Cladding Weight a Furring MaterialFraming MemberFastener Type and Minimum Size bMinimum Penetration into Wall Framing (inches)Fastener Spacing in Furring (inches)Maximum Thickness of Foam Sheathing 4* (inches)162 o.c. furring e242 o.c. furring eCladding weightCladding weight3 psf11 psf25 psf3 psf11 psf25 psfFurring MaterialFraming MemberFastener Type and Minimum Size bMinimum Penetration into Wall Framing (inches)Fastener Spacing in Furring (inches)Maximum Thickness of Foam Sheathing 4* (inches)162 o.c. furring e242 o.c. furring eCladding weightCladding weight3 psf11 psf25 psf3 psf11 psf25 psfMinimum 33 mil steel furring or minimum 1x wood furring c33 mil steel stud#8 screwSteel thickness plus 3 threads1231.5DR30.5DR1631DR2DRDR242DRDR2DRDR#10 screwSteel thickness plus 3 threads1242DR41DR1641.5DR3DRDR243DRDR2DRDR43 mil or thicker steel stud#8 screwSteel thickness plus 3 threads1231.5DR30.5DR1631DR2DRDR242DRDR2DRDR#10 screwSteel thickness plus 3 threads12431.543DR16430.542DR2442DR40.5DR For SI: 1 inch = 25.4 mm; 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa. DR = design required; o.c. = on center. a. Wood furring shall be Spruce-Pine fir or any softwood species with a specific gravity of 0.42 or greater. Steel furring shall be minimum 33 ksi steel. Steel studs shall be minimum 33 ksi steel for 33 mil and 43 mil thickness and 50 ksi steel for 54 mil steel or thicker. b. Screws shall comply with the requirements of AISI S240. c. Where the required cladding fastener penetration into wood material exceeds 3/4 inch and is not more than 1 1/2 inches, a minimum 2-inch nominal wood furring shall be used or an approved design. d. Foam sheathing shall have a minimum compressive strength of 15 pounds per square inch in accordance with ASTM C 578 or ASTM C 1289. e. 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. * Editor's note: As set forth in L.L. 2021/126; correct footnote should likely be d.
