■ ■
■ ■
Item 8: Fire-resistive joint systems may be eliminated where
openings are allowed within a fire-resistance-rated roof assembly.
In general, Section 712.1.15 will allow unprotected openings
through a fire-resistive roof assembly since the code does not
address fire spreading from the building to the outdoors. However,
several provisions-such as Exceptions 2, 3 and 4 in Section 706.6,
Exception 4 in Section 705.11, Section 706.6.1 and others will
prohibit roof openings in certain locations.
Item 9: Section 715 is not intended to regulate joints installed in
assemblies that are provided to control shrinkage cracking and
evaluated as a part of the overall assembly’s fire-resistance test.
Examples of such control joints are the limited-depth saw-cut
control joint in concrete and some of the control joint systems
used within the face layer of stucco systems. These types of joints
are made in an assembly so that cracks in the surface occur at
specific points along a straight line and not randomly across the
finished surface. Construction joints, such as the stopping and
starting points for two successive concrete pours or control joints,
which are intended to prevent shrinkage cracking (such as saw-cut
control joints) in concrete or masonry, typically accommodate very
little movement or may not go through the complete depth of the
assembly’s protection. Therefore, Item 9 in the exception does not
require compliance with ASTM E 1966 or UL 2079, as referenced
in Section 715.3, but instead permits control joints with a maximum
joint width of 5/8 inch to be tested in accordance with ASTM E 119
or UL 263. This allowance reflects fire test data that has existed
since the 1960s regarding control and perimeter relief joints in fire-
rated systems, the performance of these systems in the field and
a rational approach regarding minor movement (defined here as a
maximum of 5/8 inch) where no appreciable damage or fatigue is
incurred by the joint system. Since all buildings move slightly, it is
not prudent to have to cycle and test joint systems that only move a
few millimeters.
109