5.1. New One and Two Family Dwellings over one level in height, New One and Two Family Dwellings containing a basement, and New One and Two Family Dwellings containing a crawl space containing a fuel burning appliance below the first floor, shall provide one of the following methods for fire protection of floors: (1) A ½ inch (12.7 mm) gypsum wallboard membrane, 5/8 inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member; (2) Wood floor assemblies using dimension lumber or structural composite lumber equal or greater than 2 inch by 10 inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance; or (3) An Automatic Fire Sprinkler System as set forth in section R313.1 or R313.2 of the 2015 edition of the International Residential Code for One and Two Family Dwellings: Provided, That floor assemblies located directly over a space protected by an automatic sprinkler system as set forth in section R313.1 or R313.2 of the 2015 edition of the International Residential Code for One and Two Family Dwellings are exempt from this requirement.
5.2. Townhouses meeting the Fire-Resistant Construction Standard R302.2 will be treated as New One- and Two-Family Dwellings and shall comply with Section 5.1 above.
(Passed 7-7-22)