38A-112 NFPA 13 8.15NFPA 13 2013
8.15.1 Concealed Spaces.
8.15.1.1 Concealed Spaces Requiring Sprinkler Protection.
Concealed spaces of exposed combustible construction shall
be protected by sprinklers except in concealed spaces where
sprinklers are not required to be installed by 8.15.1.2.1
through 8.15.1.2.18 and 8.15.6.
8.15.1.2* Concealed Spaces Not Requiring Sprinkler Protection.
8.15.1.2.1* Concealed spaces of noncombustible and limitedcombustible
construction with minimal combustible loading
having no access shall not require sprinkler protection.
8.15.1.2.1.1 The space shall be considered a concealed space
even with small openings such as those used as return air for a
plenum.
8.15.1.2.2 Concealed spaces of noncombustible and limitedcombustible
construction with limited access and not permitting
occupancy or storage of combustibles shall not require
sprinkler protection.
8.15.1.2.2.1 The space shall be considered a concealed space
even with small openings such as those used as return air for a
plenum.
8.15.1.2.3 Concealed spaces formed by studs or joists with
less than 6 in. (152 mm) between the inside or near edges of
the studs or joists shall not require sprinkler protection. (See
Figure 8.6.4.1.5.1.)
8.15.1.2.4 Concealed spaces formed by bar joists with less
than 6 in. (152 mm) between the roof or floor deck and ceiling
shall not require sprinkler protection.
8.15.1.2.5* Concealed spaces formed by ceilings attached directly
to or within 6 in. (152 mm) of wood joist or similar solid
member construction shall not require sprinkler protection.
8.15.1.2.6* Concealed spaces formed by ceilings attached to
composite wood joist construction either directly or onto
metal channels not exceeding 1 in. (25.4 mm) in depth, provided
the joist channels are firestopped into volumes each not
exceeding 160 ft3 (4.53 m3) using materials equivalent to the
web construction and at least 31⁄2 in. (90 mm) of batt insulation
is installed at the bottom of the joist channels when the
ceiling is attached utilizing metal channels, shall not require
sprinkler protection.
8.15.1.2.7 Concealed spaces filled with noncombustible insulation
shall not require sprinkler protection.
8.15.1.2.7.1 A maximum 2 in. (50 mm) air gap at the top of
the space shall be permitted.
8.15.1.2.8 Concealed spaces within wood joist construction
and composite wood joist construction having noncombustible
insulation filling the space from the ceiling up to the
bottom edge of the joist of the roof or floor deck, provided
that in composite wood joist construction the joist channels
are firestopped into volumes each not exceeding 160 ft3 (4.53
m3) to the full depth of the joist with material equivalent to
the web construction, shall not require sprinkler protection.
8.15.1.2.9 Concealed spaces over isolated small rooms not
exceeding 55 ft2 (5.1 m2) in area shall not require sprinkler
protection.
8.15.1.2.10 Concealed spaces where rigid materials are used
and the exposed surfaces have a flame spread index of 25 or
less, and the materials have been demonstrated not to propagate
fire more than 10.5 ft (3.2 m) when tested in accordance
withASTM E 84, Standard Test Method of Surface Burning Characteristics
of Building Materials, or ANSI/UL 723, Standard for Test
for Surface Burning Characteristics of Building Materials, extended
for an additional 20 minutes in the form in which they are
installed, shall not require sprinkler protection.
8.15.1.2.11* Concealed spaces in which the exposed materials
are constructed entirely of fire retardant–treated wood as defined
by NFPA 703 shall not require sprinkler protection.
8.15.1.2.12 Noncombustible concealed spaces having exposed
combustible insulation where the heat content of the
facing and substrate of the insulation material does not exceed
1000 Btu/ft2 (11,356 kJ/m2) shall not require sprinkler
protection.
8.15.1.2.13 Concealed spaces below insulation that is laid directly
on top of or within wood joists or composite wood joists
used as ceiling joists in an otherwise sprinklered concealed
space, with the ceiling attached directly to the bottom of the
joists, shall not require sprinkler protection.
8.15.1.2.14 Vertical pipe chases under 10 ft2 (0.93m2), where
provided in multifloor buildings where the chases are firestopped
at each floor using materials equivalent to the floor
construction, and where such pipe chases shall contain no
sources of ignition, piping shall be water-filled or noncombustible
and pipe penetrations at each floor shall be properly
sealed and shall not require sprinkler protection.
8.15.1.2.15 Exterior columns under 10 ft2 (0.93 m2) in area,
formed by studs or wood joist supporting exterior canopies
that are fully protected with a sprinkler system, shall not require
sprinkler protection.
8.15.1.2.16* Concealed spaces formed by noncombustible or
limited-combustible ceilings suspended from the bottom of
wood joists, composite wood joists, wood bar joists, or wood
trusses that have insulation filling all of the gaps between the
bottom of the trusses or joists, and where sprinklers are
present in the space above the insulation within the trusses or
joists, shall not require sprinkler protection.
8.15.1.2.16.1 The heat content of the facing, substrate, and support
of the insulation material shall not exceed 1000 Btu/ft2
(11,356 kJ/m2).
8.15.1.2.17* Concealed spaces formed by noncombustible or
limited-combustible ceilings suspended from the bottom of
wood joists and composite wood joists with a maximum nominal
chord width of 2 in. (50.8 mm), where joist spaces are full of
noncombustible batt insulation with a maximum 2 in. (50.8 m)
air space between the roof decking material and the top of the
batt insulation shall not require sprinklers.
8.15.1.2.17.1 Facing that meets the requirements for noncombustible
or limited-combustible material covering the surface of
the bottom chord of each joist and secured in place per the
manufacturer’s recommendations shall not require sprinklers.