Section 362.1405. Exterior walls.

 

(1)  This is a department exception in addition to the exceptions in IBC section 1405.3: Where other approved means to avoid condensation in unventilated framed wall, floor, roof and ceiling cavities and box sills are provided.

(2)  This is a department rule in addition to the requirements in IBC section 1405.14.1: Polystyrene sheathing may be utilized as the required backing material for vinyl siding provided all of the following characteristics and conditions are met:

(a) The sheathing is extruded, rigid and cellular.

(b) The sheathing is type IV, as specified in ASTM C578.

(c) The sheathing has a thickness of at least one inch.

(d) The sheathing is installed with an on-center stud spacing of 16 inches or less.

(e) The mean roof height of the building is 40 feet or less.

(f) The building wall has a wind exposure category of B or C, as established in IBC section 1609.4; and the building is not sited on the upper half of an isolated hill or escarpment meeting conditions 1, 2, and 3 in IBC section 1609.1.1.1.

CR 04-016 : cr. Register December 2004 No. 588 , eff. 1-1-05; CR 06-120 : am. (2) (c) 3. Register February 2008 No. 626 , eff. 3-1-08; CR 10-103 : r. and recr. Register August 2011 No. 668 , eff. 9-1-11.