International Building Code Section 1403

International Building Code 1403.1

General. The provisions of this section shall apply to
exterior walls, wall coverings and components thereof.

International Building Code 1403.2

Weather protection. Exterior walls shall provide the
building with a weather-resistant exterior wall envelope. The
exterior wall envelope shall include flashing, as described in
Section 1405.3. The exterior wall envelope shall be designed
and constructed in such a manner as to prevent the accumulation
of water within the wall assembly by providing a
water-resistive barrier behind the exterior veneer, as described
in Section 1404.2, and a means for draining water that enters
the assembly to the exterior. Protection against condensation in
the exteriorwall assembly shall be provided in accordance with
the International Energy Conservation Code.
1. A weather-resistant exterior wall envelope shall not
be required over concrete or masonry walls designed
in accordance with Chapters 19 and 21, respectively.
2. Compliance with the requirements for a means of
drainage, and the requirements of Sections 1404.2
and 1405.3, shall not be required for an exterior wall
envelope that has been demonstrated through testing
to resist wind-driven rain, including joints, penetrations
and intersections with dissimilar materials, in
accordance with ASTM E 331 under the following
2.1. Exterior wall envelope test assemblies shall
include at least one opening, one control joint,
one wall/eave interface and one wall sill. All
tested openings and penetrations shall be representative
of the intended end-use configuration.
2.2. Exterior wall envelope test assemblies shall
be at least 4 feet by 8 feet (1219 mm by 2438
mm) in size.
2.3. Exterior wall envelope assemblies shall be
tested at a minimum differential pressure of
6.24 pounds per square foot (psf) (0.297
2.4. Exterior wall envelope assemblies shall be
subjected to a minimum test exposure duration
of 2 hours.
The exterior wall envelope design shall be considered
to resist wind-driven rain where the results of
testing indicate that water did not penetrate control
joints in the exterior wall envelope, joints at the perimeter
of openings or intersections of terminations
with dissimilar materials.

International Building Code 1403.3

Structural. Exterior walls, and the associated openings,
shall be designed and constructed to resist safely the
superimposed loads required by Chapter 16.

International Building Code 1403.4

Fire resistance. Exterior walls shall be fire-resistance
rated as required by other sections of this code with opening
protection as required by Chapter 7.

International Building Code 1403.5

Flood resistance. For buildings in flood hazard areas as
established in Section 1612.3, exterior walls extending below
the design flood elevation shall be resistant to water damage.
Wood shall be pressure-preservative treated in accordance with
AWPA U1 for the species, product and end use using a preservative
listed in Section 4 of AWPAU1 or decay-resistant heartwood
of redwood, black locust or cedar.

International Building Code 1403.6

Flood resistance for high-velocity wave action areas.
For buildings in flood hazard areas subject to high-velocity
wave action as established in Section 1612.3, electrical,
mechanical and plumbing system components shall not be
mounted on or penetrate through exterior walls that are
designed to break away under flood loads.