Originally posted by travisfl
Originally posted by dash
I think you'll find the sheet metal in the code "to be" adopted ,maybe this October.
From the 2003 IRC:

SECTION R309
- GARAGES AND CARPORTS
- - - R309.1.1 Duct penetration. Ducts in the garage and ducts penetrating the walls or ceilings separating the dwelling from the garage shall be constructed of a minimum No. 26 gage (0.48 mm) sheet steel or other approved material and shall have no openings into the garage. [/B]
Seriously we do a lot of new construction,that provision in the mech. code was deleted ,but is contained in the buiding code,and is not in effect in Florida at this time.