(A) All conditioned spaces shall have all interior wall and ceiling surfaces covered with a minimum of one-half inch gypsum wallboard or approved equal. One inch nominal solid paneling shall not be required to have a drywall backing.
Exception 1: Three-season rooms that do not contain conditioned space
Exception 2: Screened porches
Exception 3: Unfinished crawl spaces unless required by R302.13
Exception 4: Unfinished basements and unfinished areas of basements except as required by R302.13 or another area of this ordinance.
Exception 5: Ceilings of finished basements unless required by R302.13
Exception 6: Commercial & Industrial structures complying with 2018 IBC
Exception 7: Detached accessory structures as long as they are covered with plywood and sealed per energy code reguirements.
Exception 8: Greenhouses
(B) In all commercial, industrial multi-tenant buildings, and residential multi-tenant buildings, a minimum one hour fire wall shall be provided between tenant spaces.
(C) Fire blocking compounds shall have a flame spread rating no greater than 50 and comply with ASTM E-84. Approved fireplace caulk, noncombustible mineral wool or rock wool is acceptable but in no case shall fiberglass or cellulose insulation or drywall compound be used as a fire or draft stop.
(D) A mansard roof must be fire blocked at the corners to prevent fire from engulfing the perimeter of the building. Access panels shall be provided for inspection.
(E) All manufactured fireplace shaft-walls and ceilings shall be covered with 5/8" fire rated drywall taped with at least one coat of joint compound facing the fireplace. A false ceiling can be installed at 8' for the installation of the fire rated drywall. The fire rated drywall at the ceiling shall leave a 2" clearance to the chimney with a fire caulked metal collar. Manufactured fire boxes shall be. The chimney shaft wall of a manufactured (pre-fab) fireplace shall be separated from any attic areas with not less than 7/16" structural sheathing.
(F) An attached garage shall be completely separated from the residence and the residence attic areas by a minimum 5/8" fire rated drywall applied to the garage side with joints properly taped and sealed with at least one coat of joint compound, or equivalent. Structural members shall not protrude thru this fire protection. A 2 x member shall be considered equivalent to the 5/8" fire rated drywall if fire caulked above and below for the purpose of this section. The drywall shall be installed on the wall and the ceiling of the attached garage or on the wall only from concrete to roof sheathing. Detached garages less than 3' from the single family residence, duplex or townhouse shall have 5/8" fire code drywall on the garage side of the wall and on the ceiling. Walls more than 3' and perpendicular walls need not have any protection. Eave protection shall not be required if the distance from eave to eave is 5'.
(G) Accessory structures greater than 10' from homes and 5' from lot lines can use an ignition barrier for spray foam insulation.
(H) Stair treads and risers shall have 1/2" drywall finish on the underside when accessing a 2nd floor or a basement less than 5' below grade.
(I) Fire walls for three season rooms within 5' of an assumed lot line between townhouses and duplex's shall only be required for the first 4' projection from the residence as long as built of non-combustible material or 1/2" drywall finishes are installed at all portions of the room.
(J) Spray foam insulation and rigid foam insulation shall be allowed to be left exposed at rim joists of unfinished crawl spaces and basements and above attic access panels without drywall covering or ignition barriers.
(Ord. 21-102, passed 8-19-2021)