Roof assemblies shall be divided into the classes defined below. Class A, B and C roof assemblies and roof coverings required to be listed by this section shall be tested in accordance with ASTM E 108 or UL 790. In addition, fire-retardant-treated wood roof coverings shall be tested in accordance with ASTM D 2898. The minimum roof coverings installed on buildings shall comply with Table 1505.1 based on the type of construction of the building.
Exception: Skylights and sloped glazing that comply with Chapter 24 or Section 2610.
TABLE 1505.1a, b MINIMUM ROOF COVERING CLASSIFICATION FOR TYPES OF CONSTRUCTION
IA | IB | IIA | IIB | IIIA | IIIB | IV | VA | VB |
B | B | B | Cc | B | Cc | B | B | Cc |
For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2. a. Unless otherwise required in accordance with the International Wildland-Urban Interface Code or due to the location of the building within a fire district in accordance with Appendix D. b. Nonclassified roof coverings shall be permitted on buildings of Group R-3 and Group U occupancies, where there is a minimum fire-separation distance of 6 feet measured from the leading edge of the roof. c. Buildings that are not more than two stories above grade plane and having not more than 6,000 square feet of projected roof area and where there is a minimum 10-foot fire-separation distance from the leading edge of the roof to a lot line on all sides of the building, except for street fronts or public ways, shall be permitted to have roofs of No. 1 cedar or redwood shakes and No. 1 shingles. |
780 CMR, 1505.1