(a) The provisions of this section shall govern the requirements and uses of foam plastic insulation.
(b) Except where otherwise noted, all foam plastic or foam plastic cores in manufactured assemblies used in building construction shall have a flame-spread rating of not more than twenty-five and shall have a smoke-developed rating of not more than 175 when tested in the maximum thickness intended for use in accordance with American Society for Testing and Materials E84-1987 (refer to Appendix A).
(c) Foam plastic may be used in a roof-covering assembly without the thermal barrier when the foam is separated from the interior of the building by plywood sheathing not less than five-eighths of an inch in thickness, bonded with exterior glue, with the edge supported by blocking, tongue and groove joints or other approved type of edge support, or an equivalent material.
(d) Within an attic or crawl space, where entry is made only for service of utilities, foam plastics shall be protected against ignition by one and one-half inches thick mineral fiber insulation, five-eighths of an inch thick plywood, or five-eighths of an inch gypsum wallboard, or other approved material installed in such a manner that the foam plastic is not exposed. The protective covering shall be consistent with the requirements for the type of construction.
(Ord. 1992-101. Passed 1-14-92.)