International Building Code Section 1909


International Building Code 1909.1

Scope. The design and construction of structural plain
concrete, both cast-in-place and precast, shall comply with the
minimum requirements of Section 1909 and ACI 318, Chapter
22, as modified in Section 1908.

Special structures. For special structures, such as
arches, underground utility structures, gravity walls and
shielding walls, the provisions of this section shall govern
where applicable.

International Building Code 1909.1.1

Special structures. For special structures, such as
arches, underground utility structures, gravity walls and
shielding walls, the provisions of this section shall govern
where applicable.

International Building Code 1909.2

Limitations. The use of structural plain concrete shall
be limited to:
1. Members that are continuously supported by soil, such
as walls and footings, or by other structural members
capable of providing continuous vertical support.
2. Members for which arch action provides compression
under all conditions of loading.
3. Walls and pedestals.
The use of structural plain concrete columns and structural
plain concrete footings on piles is not permitted. See Section
1908.1.15 for additional limitations on the use of structural
plain concrete.

International Building Code 1909.3

Joints. Contraction or isolation joints shall be provided
to divide structural plain concrete members into flexurally discontinuous
elements in accordance withACI 318, Section 22.3.

International Building Code 1909.4

Design. Structural plain concrete walls, footings and
pedestals shall be designed for adequate strength in accordance
with ACI 318, Sections 22.4 through 22.8.
Exception: For Group R-3 occupancies and buildings of
other occupancies less than two stories in height of
light-frame construction, the required edge thickness of
ACI 318 is permitted to be reduced to 6 inches (152 mm),
provided that the footing does not extend more than 4 inches
(102 mm) on either side of the supported wall.

International Building Code 1909.5

Precast members. The design, fabrication, transportation
and erection of precast, structural plain concrete elements
shall be in accordance with ACI 318, Section 22.9.

International Building Code 1909.6

Walls. In addition to the requirements of this section,
structural plain concretewalls shall comply with the applicable
requirements of ACI 318, Chapter 22.

Basement walls. The thickness of exterior basement
walls and foundation walls shall be not less than 71/2
inches (191 mm). Structural plain concrete exterior base-
2006 INTERNATIONAL BUILDING CODE 379
CONCRETE
ment walls shall be exempt from the requirements for special
exposure conditions of Section 1904.2.2.

Other walls. Except as provided for in Section
1909.6.1, the thickness of bearing walls shall be not less
than 1/24 the unsupported height or length, whichever is
shorter, but not less than 51/2 inches (140 mm).

Openings in walls. Not less than two No. 5 bars
shall be provided around window and door openings. Such
bars shall extend at least 24 inches (610 mm) beyond the
corners of openings.

International Building Code 1909.6.1

Basement walls. The thickness of exterior basement
walls and foundation walls shall be not less than 71/2
inches (191 mm). Structural plain concrete exterior base-
2006 INTERNATIONAL BUILDING CODE 379
CONCRETE
ment walls shall be exempt from the requirements for special
exposure conditions of Section 1904.2.2.

International Building Code 1909.6.2

Other walls. Except as provided for in Section
1909.6.1, the thickness of bearing walls shall be not less
than 1/24 the unsupported height or length, whichever is
shorter, but not less than 51/2 inches (140 mm).

International Building Code 1909.6.3

Openings in walls. Not less than two No. 5 bars
shall be provided around window and door openings. Such
bars shall extend at least 24 inches (610 mm) beyond the
corners of openings.