13VAC5-63-298: Chapter 26 Plastic

Change Section 2603.5.5 of the IBC to read:

2603.5.5 Vertical and lateral fire propagation. Exterior wall assemblies shall be tested in accordance with, and comply with, acceptance criteria of NFPA 285. Where noncombustible materials or combustible materials permitted by Section 603, 803, 806 or 1405 differ from assembly to assembly or within an assembly, multiple tests shall not be required.

Exceptions:

1. One-story buildings where the exterior wall covering is noncombustible.

2. Wall assemblies where the foam plastic insulation is covered on each face by not less than 1-inch (25 mm) thickness of masonry or concrete and meeting one of the following:

2.1. There is no air space between the insulation and the concrete or masonry.

2.2. The insulation has a flame spread index of not more than 25 as determined in accordance with ASTM E 84 or UL 723 and the maximum air space between the insulation and the concrete or masonry is not more than 1 inch (25 mm).

3. Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.