R302.5.2

Section R302.5.2 is titled 'Duct penetrations' and covers the requirements for ducts in garages and which penetrate an assembly that separates an attached garage from a dwelling. Allowable duct material, thickness of metal duct, and disallowance for duct openings within the garage is established. The purpose of this section is to slow the spread of fire, heat, smoke, and vehicle exhaust through an assembly that separates an attached garage from a dwelling.

The model shows a partial section of a wall which separates a dwelling from its attached garage with the duct highlighted.