International Building Code Section 603


International Building Code 603.1

TYPES OF CONSTRUCTION

Allowable materials. Combustible materials shall be
permitted in buildings of Type I or Type II construction in the
following applications and in accordance with Sections
603.1.1 through 603.1.3:
1. Fire-retardant-treated wood shall be permitted in:
1.1. Nonbearing partitions where the required
fire-resistance rating is 2 hours or less.
1.2. Nonbearing exterior walls where no fire rating is
required.
1.3. Roof construction, including girders, trusses,
framing and decking.
Exception: In buildings of Type I construction
exceeding two stories in height,
fire-retardant-treated wood is not permitted in
roof construction when the vertical distance
from the upper floor to the roof is less than 20
feet (6096 mm).
2. Thermal and acoustical insulation, other than foam
plastics, having a flame spread index of not more than
25.
Exceptions:
1. Insulation placed between two layers of
noncombustible materials without an intervening
airspace shall be allowed to have a flame
spread index of not more than 100.
2. Insulation installed between a finished floor
and solid decking without intervening airspace
shall be allowed to have a flame spread index of
not more than 200.
3. Foam plastics in accordance with Chapter 26.
4. Roof coverings that have an A, B or C classification.
5. Interior floor finish and interior finish, trim and millwork
such as doors, door frames, window sashes and
frames.
6. Where not installed over 15 feet (4572 mm) above
grade, show windows, nailing or furring strips and
wooden bulkheads below show windows, including
their frames, aprons and show cases.
7. Finished flooring applied directly to the floor slab or to
wood sleepers that are fireblocked in accordance with
Section 717.2.7.
8. Partitions dividing portions of stores, offices or similar
places occupied by one tenant only and that do not
establish a corridor serving an occupant load of 30 or
more shall be permitted to be constructed of fire-retardant-
treated wood, 1-hour fire-resistance-rated construction
or of wood panels or similar light construction
up to 6 feet (1829 mm) in height.
9. Stages and platforms constructed in accordance with
Sections 410.3 and 410.4, respectively.
10. Combustible exterior wall coverings, balconies and
similar projections and bay or oriel windows in accordance
with Chapter 14.
11. Blocking such as for handrails, millwork, cabinets and
window and door frames.
12. Light-transmitting plastics as permitted by Chapter 26.
13. Mastics and caulking materials applied to provide flexible
seals between components of exterior wall construction.
14. Exterior plastic veneer installed in accordance with
Section 2605.2.
15. Nailing or furring strips as permitted by Section 803.4.
16. Heavy timber as permitted by Note d to Table 601 and
Sections 602.4.7 and 1406.3.
17. Aggregates, component materials and admixtures as
permitted by Section 703.2.2.
18. Sprayed fire-resistant materials and intumescent and
mastic fire-resistant coatings, determined on the basis
of fire-resistance tests in accordance with Section
703.2 and installed in accordance with Section 1704.10
and 1704.11, respectively.
19. Materials used to protect penetrations in fire-resistance-
rated assemblies in accordance with Section 712.
20. Materials used to protect joints in fire-resistance-rated
assemblies in accordance with Section 713.
21 Materials allowed in the concealed spaces of buildings
of Type I and II construction in accordance with Section
717.5.
22. Materials exposed within plenums complying with
Section 602 of the International Mechanical Code.

Ducts. The use of nonmetallic ducts shall be permitted
when installed in accordance with the limitations of
the International Mechanical Code.

Piping. The use of combustible piping materials
shall be permitted when installed in accordance with the
limitations of the International Mechanical Code and the
International Plumbing Code.

Electrical. The use of electrical wiring methods
with combustible insulation, tubing, raceways and related
components shall be permitted when installed in accordance
with the limitations of the ICC Electrical Code.

International Building Code 603.1.1

Ducts. The use of nonmetallic ducts shall be permitted
when installed in accordance with the limitations of
the International Mechanical Code.

International Building Code 603.1.2

Piping. The use of combustible piping materials
shall be permitted when installed in accordance with the
limitations of the International Mechanical Code and the
International Plumbing Code.

International Building Code 603.1.3

Electrical. The use of electrical wiring methods
with combustible insulation, tubing, raceways and related
components shall be permitted when installed in accordance
with the limitations of the ICC Electrical Code.