(a) Roof rafters shall have a minimum slope of 4:12 and shall be covered on their top surface with one-half (½) inch solid sheathing and any roof covering allowed by this Code.
(b) Attic insulation shall be batt or blown-in glass fiber or mineral wool with a minimum R-30 rating applied between the ceiling joists.
(c) Attic ventilation shall be:
(1) Gable vents or vents that penetrate the roof surface that are fitted with transfer ducts at least six (6) feet in length that are insulating flexible ducting or metal ducts containing internal one (1) inch thick coated fiberglass sound-absorbing duct liner. Each duct shall have a lined ninety (90) degree bend in the duct so that there is no direct line-of-sight from the exterior through the duct into the attic; or
(2) Noise control louver vents; or
(3) Eave vents that are located under the cave overhang.
(d) Ceilings shall be finished with gypsum board or plaster that is at least five-eighths (
5/8
) inch thick. Ceiling materials shall be mounted on resilient channels.
(e) Skylights shall penetrate the ceiling by means of a completely enclosed light well that extends from the roof opening to the ceiling opening. A secondary openable glazing panel shall be mounted at the ceiling line or at a point that provides at least a four (4) inch space between the skylight glazing and the secondary glazing and shall be glazed with at least three-sixteenths (3/16) inch plastic or laminated glass. The weather-side skylight shall be any type that is permitted by the Building Code. The size of skylights shall be no more than twenty (20) percent of the roof area of the room.
(§ 2, Ord. 2616, eff. June 20, 1996)