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An important aspect of limiting the spread of fire, smoke and toxic gases is ensuring horizontal and vertical mechanical metallic ducts are not a conduit throughout a building during a fire. The code achieves this by requiring the protection of certain ductwork by fire-resistance rated (FRR) shaft enclosures. Unfortunately, many fire-resistance rated duct assemblies do not meet this basic requirement for fire resistance from both the outside of the duct and the inside. While presented as fire-resistive, they cannot withstand fire exposure, wherever symmetry testing is mandated.

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After reading this paper, you will:

  • Learn what fire-resistance rating symmetry is and how it applies to vertical and horizontal duct assemblies
  • Understand the requirements of the International Building Code (ICC) and how they relate to practical applications
  • Review current challenges with practical applications
  • Prepare for an alternative code path using fire resistance duct assemblies

Read the whitepaper.

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