NFPA Journal - November/December 2019 - 41

In Compliance
risk analysis checklist in the annex.
Understandably, a jurisdiction may
not have yet adopted the 2016 or later
editions of the code. However, most
jurisdictions will allow the reference
to a more current edition of the code
when the later edition provides guidance to help meet a specific code
requirement.
The risk analysis is typically not
difficult to develop or approve. It
simply provides the guidance necessary to ensure that the stakeholders
have considered all of the reasonable and likely risks and developed
appropriate actions and messages, as
necessary. For approval purposes, the
AHJ becomes a required stakeholder
involved in all the meetings that determine the appropriate responses to
each risk. Based on the process, AHJs
should have little difficulty approving
a document they had a part in creating. However, if the AHJ does not feel
competent in the area of risk analysis, NFPA 101 in sections 4.6.1.4 and
9.14.3.2 allows the AHJ to request a
third-party review.
The risk analysis becomes a part
of the owner's emergency response
plan. Thus, such a plan may have
already completed critical elements of
the risk analysis. The 2019 edition of
NFPA 72 recognizes this and permits
the risk analysis to serve as a baseline in preparing other risk analyses
for new or renovated facilities that
have similar features. In that case,
the MNS-which becomes a small,
but important, part of the emergency
response plan-can use the previously
established risk analysis.
NFPA 72 also allows the limited
scope of the risk analysis to only
address the communication requirements of an existing emergency
response plan. Given the assistance
provided in NFPA 72, especially in the
later editions, requiring a risk analysis
should not create a hardship or stumbling block to designing and installing
a mass notification system.
Wayne D. Moore is vice president at Jensen
Hughes. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA 72
at nfpa.org/72.

NFPA 13

Water-based fire
protection systems

Why nonmetallic tubes
are no longer a pipe dream
for residential garages
By Brian O'Connor
aterial science is a

M

complicated topic, but
requirements exist
that can help designers narrow down their
options for choosing the piping that is
appropriate for their project. To help
in this process, the 2019 edition of
NFPA 13, Standard for the Installation
of Sprinkler Systems, includes a new
provision for the use of nonmetallic
piping in certain garages.
The selection of material for use in
aboveground piping applications is
governed by relatively straightforward
requirements. NFPA 13, Table 7.3.1.1
lists standards that the pipe needs to
meet or exceed when used as part of
a sprinkler system. This makes sense
since you only want to use piping
that was designed to perform in a fire
event or in a range of environmental
conditions. The table breaks the standards into groups for ferrous (steel),
copper, brass, stainless steel, and
CPVC (plastic); each has its advantages
and disadvantages, as well as specific
requirements for when it can be used.
Steel is the most common type of
piping used in sprinkler systems.
Benefits of steel include its cost-effectiveness, durability, fire resistance,
and rigidity, which allows hangers
to be spaced further apart per Table
17.4.2.1(a). On the other hand, steel
may not be the first choice of designers for some projects; it can be heavier
than other materials, meaning it could
require additional labor for installation, and it is susceptible to pitting and
corrosion.
Copper and copper alloys such as
brass are more corrosion-resistant than

steel, which helps them stay smoother
internally. This can mean less friction
in the pipe, reducing the required pressure of your system. But these metals
are also among the more expensive
piping materials.
Nonmetallic piping such as CPVC
is one of the more affordable materials. It is also flexible, has the highest
corrosion resistance, and is smoother
than most metals. CPVC is not as
durable or fire-resistant as other materials, however, which is why it is only
allowed in certain settings, such as
light-hazard occupancy areas or ordinary-hazard rooms that do not exceed
400 square feet within a light-hazard
occupancy.
Other factors to consider when
choosing a material to use include the
environmental conditions of the space
where the pipe is installed. For example, some industrial occupancies could
require a corrosion-resistant piping
material to be installed, while an MRI
machine room in a hospital would
require the use of non-ferrous material. The desire to achieve a certain
aesthetic appearance could also influence material selection.
In addition to previously existing NFPA 13 requirements, there is a
new section (16.3.9.6.2) in the 2019
edition that gives users more flexibility by permitting the use of nonmetallic
piping in certain private garages within
dwelling units. As mentioned, nonmetallic piping is permitted for use in
light-hazard areas and in ordinary-hazard rooms not exceeding 400 square
feet. Some authorities interpreted this
point as permitting only metallic pipe
in residential garages over 400 square
feet, even if the rest of the system used
CPVC. This new provision now allows
nonmetallic piping to be installed in
a private garage within a dwelling as
long as the garage space itself does
not exceed 1,000 square feet and it is
protected by the appropriate wall or
ceiling sheathing.
It is important to note that larger
automobile parking garages should
be considered ordinary-hazard group
1 occupancies. The specific allowance for using CPVC is intended to
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NFPA Journal - November/December 2019

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