Fire Stop Systems Brochure SA727 - USG Corporation

Construction Joint Fire Tests
Construction joints are used at locations where two fire-rated
assemblies intersect. These locations include:
– Wall to floor/ceiling or roof/ceiling (head-of-wall application)
– Wall to wall (building expansion joint application)
– Floor to floor (building expansion joint application)
– Floor to wall
Construction joints are evaluated in accordance with the Standard
ASTM E1966 (ANSI/UL 2079) for their ability to resist flame and
temperature transmission as well as the hose stream.
A special variation to construction joints is the intersection of a
fire-rated floor and an exterior curtain wall. According to UL, curtain
wall slab edge conditions are not suitable for evaluation under UL 2079
because curtain walls are primarily non-fire-rated assemblies.
Underwriters Laboratories has evaluated several United States Gypsum
Company head-of-wall assemblies under the Standard UL 2079. These
assemblies are recognized by ICBO (ER-2331).
These assemblies are separated into static (no floor or roof movement)
and dynamic (to accommodate deflection). Allowable movement is
noted in the separate designs.
29 USG Fire Stop Systems