Except as provided for in Sections 2603.4.1 and 2603.9, foam
plastic shall be separated from the interior of a building by an approved
thermal barrier of 1/2-inch
(12.7 mm) gypsum wallboard or equivalent thermal barrier material that will
limit the average temperature rise of the unexposed surface to not more than
250°F (120°C) after 15 minutes of fire exposure, complying with the
standard time-temperature curve of ASTM E 119 or UL 263. The thermal barrier
shall be installed in such a manner that it will remain in place for 15 minutes
based on FM 4880, UL 1040, NFPA 286 or UL 1715. Combustible concealed spaces
shall comply with Section 717.
2603.4.1
Thermal barrier not
required. The thermal barrier specified in Section 2603.4 is not
required under the conditions set forth in Sections 2603.4.1.1 through
2603.4.1.13.
2603.4.1.1
Masonry or
concrete construction. A thermal barrier is not required for foam
plastic installed in a masonry or concrete wall, floor or roof system where the
foam plastic insulation is covered on each face by a minimum of 1 inch (25 mm)
thickness of masonry or concrete.
2603.4.1.2
Cooler and freezer
walls. Foam plastic installed in a maximum thickness of 10 inches (254
mm) in cooler and freezer walls shall:
1. Have
a flame spread index of 25 or less and a smoke-developed index of not more than
450, where tested in a minimum 4 inch (102 mm) thickness.
2. Have flash ignition and self-ignition
temperatures of not less than 600°F and 800°F (316°C and
427°C), respectively.
3. Have a
covering of not less than 0.032-inch (0.8 mm) aluminum or corrosion-resistant
steel having a base metal thickness not less than 0.0160 inch (0.4 mm) at any
point.
4. Be protected by an
automatic sprinkler system in accordance with Section
903.3.1.1. Where the cooler or freezer is within a building, both the cooler or
freezer and that part of the building in which it is located shall be
sprinklered.
2603.4.1.3
Walk-in coolers. In nonsprinklered buildings, foam plastic having
a thickness that does not exceed 4 inches (102 mm) and a maximum flame spread
index of 75 is permitted in walk-in coolers or freezer units where the
aggregate floor area does not exceed 400 square feet (37
m2) and the foam plastic is covered by a metal
facing not less than 0.032-inch-thick (0.81 mm) aluminum or corrosion-resistant
steel having a minimum base metal thickness of 0.016 inch (0.41 mm). A
thickness of up to 10 inches (254 mm) is permitted where protected by a thermal
barrier.
2603.4.1.4
Exterior
walls-one-story buildings. For one-story buildings,
foam plastic having a flame spread index of 25 or less, and a smoke-developed
index of not more than 450, shall be permitted without thermal barriers in or
on exterior walls in a thickness not more than 4 inches (102
mm) where the foam plastic is covered by a thickness of not less than
0.032-inch-thick (0.81 mm) aluminum or corrosion-resistant steel having a base
metal thickness of 0.0160 inch (0.41 mm) and the building is equipped
throughout with an automatic sprinkler system in accordance
with Section 903.3.1.1.
2603.4.1.5
Roofing. Foam plastic insulation under a roof assembly or roof
covering that is installed in accordance with the code and the manufacturer's
instructions shall be separated from the interior of the building by wood
structural panel sheathing not less than 0.47 inch (11.9 mm) in thickness
bonded with exterior glue, with edges supported by blocking, tongue-and-groove
joints or other approved type of edge support, or an equivalent material. A
thermal barrier is not required for foam plastic insulation that is a part of a
Class A, B or C roof-covering assembly, provided the assembly with the foam
plastic insulation satisfactorily passes FM 4450 or UL 1256.
2603.4.1.6
Attics and crawl
spaces. Within an attic or crawl space where entry is
made only for service of utilities, foam plastic insulation shall be protected
against ignition by
11/2-inch-thick (38 mm)
mineral fiber insulation;
1/4-inch-thick (6.4 mm) wood
structural panel, particleboard or hardboard;
3/8-inch (9.5 mm) gypsum
wallboard, corrosion-resistant steel having a base metal thickness of 0.016
inch (0.4 mm) or other approved material installed in such a manner that the
foam plastic insulation is not exposed. The protective covering shall be
consistent with the requirements for the type of construction.
2603.4.1.7
Doors not required to have a
fire protection rating. Where pivoted or side-hinged doors are permitted
without a fire protection rating, foam plastic insulation, having a flame
spread index of 75 or less and a smoke-developed index of not more than 450,
shall be permitted as a core material where the door facing is of metal having
a minimum thickness of 0.032-inch (0.8 mm) aluminum or steel having a base
metal thickness of not less than 0.016 inch (0.4 mm) at any point.
2603.4.1.8
Exterior doors in buildings
of Group R-2 or R-3. In occupancies classified as Group R-2 or R-3,
foam-filled exterior entrance doors to individual dwelling
units that do not require a fire-resistance rating shall be faced with
wood or other approved materials.
2603.4.1.9
Garage doors. Where
garage doors are permitted without a fire-resistance rating and foam plastic is
used as a core material, the door facing shall be metal having a minimum
thickness of 0.032-inch (0.8 mm) aluminum or 0.010-inch (0.25 mm) steel or the
facing shall be minimum 0.125-inch-thick (3.2 mm) wood. Garage doors having
facings other than those described above shall be tested in accordance with,
and meet the acceptance criteria of, DASMA 107.
Exception: Garage doors using foam plastic
insulation complying with Section 2603.3 in detached and attached garages
associated with one- and two-family dwellings need not be provided with a
thermal barrier.
2603.4.1.10
Siding backer board.
Foam plastic insulation of not more than 2,000 British thermal units per square
feet (Btu/sq. ft.) (22.7 mJ/m2) as determined by
NFPA 259 shall be permitted as a siding backer board with a maximum thickness
of 1/2 inch (12.7 mm),
provided it is separated from the interior of the building by not less than 2
inches (51 mm) of mineral fiber insulation or equivalent or where applied as
insulation with residing over existing wall construction.
2603.4.1.11
Interior trim. Foam
plastic used as interior trim in accordance with Section 2604
shall be permitted without a thermal barrier.
2603.4.1.12
Interior signs. Foam
plastic used for interior signs in covered mall buildings in
accordance with Section 402.16 shall be permitted without a thermal barrier.
Foam plastic signs that are not affixed to interior building surfaces shall
comply with Chapter 8 of the International Fire
Code.
2603.4.1.13
Type V construction. Foam plastic spray applied to a sill plate and
header of Type V construction is subject to all of the following:
1. The maximum thickness of the foam plastic
shall be 31/4 inches (82.6
mm).
2. The density of the foam
plastic shall be in the range of 1.5 to 2.0 pcf (24 to 32
kg/m3).
3. The foam plastic shall have a flame spread
index of 25 or less and an accompanying smoke-developed index of 450 or less
when tested in accordance with ASTM E 84 or UL 723.