A structure with modern
furnishings and material
flashes over in 3 minutes
and 40 seconds!
FIGURE 1: A conduit penetration occurrence at left versus a properly sealed conduit opening at right.
March/April 2019 I 57
Modern structures are filled with combustible
materials. The increased use of synthetic materials,
such as foams and plastics, when compared to the
materials used a few decades ago changes the dynamics
considerably. According to an online video of
a demonstration conducted by Underwriters Laboratories
Inc. (UL), a structure with modern furnishings
and material flashes over in 3 minutes and 40 seconds,
whereas one with more traditional furnishings takes
closer to 30 minutes.1
When it comes to passive fire protection, buildings
are essentially built with a series of fire-rated
compartments made up of fire-rated floors and walls.
When these compartments are breached by various
building service elements such as pipes, conduits,
cables, and ducts, their fire-rating and ability to resist
smoke migration is compromised. Firestopping, thus,
is the process of installing third-party tested and listed
materials into openings in fire-rated barriers to restore
fire-resistance ratings. Building and fire codes, such
as NFPA, ICC and European standards, require that
such ratings be restored through firestopping, making
penetration firestops a vitally important topic.
The firestopping process of installing third-party
tested and listed materials into openings in fire-rated
partitions maintains these fire-resistance ratings. This is
usually a simple process when thought of ahead of time,
but can become painful and expensive if done after the
fact. Avoiding it altogether will put any type of structure
at risk, even if it is protected by a sprinkler system.
A penetration occurs when a service element breaches
a fire-rated barrier. In Figure 1, the red object at the
left represents a conduit penetrating a fire-rated
compartment. If the opening around the conduit is
unprotected, the fire has a path to propagate quickly
into the adjoining space. The right-hand image shows
a properly installed firestop system that seals the
opening around the conduit and restores the fire rating
of the barrier. Fire and smoke are now contained to
the compartment of origin.
For many people, the notion of firestopping means
red caulk around conduits or cables. However, what
good is a great caulk if the barrier cannot withstand
the fire? Therefore, a firestop system starts with the
fire-rated barrier itself, whether a floor or a wall, then
the opening and what goes through it. Finally comes
the firestop product installed into the opening
as described by a UL-classified firestop system, a factory
mutual (FM) approved design, or as tested to the
European standard EN 1366. The complete assemblage
of elements, which is called a system, achieves the
rating, not an individual product.