Page 315 - 2018_IRC

WALL CONSTRUCTION

values, are permitted to be reduced by multiplying by the opening size and location are not restricted provided there
applicable factor, R , from Table R608.7(4). The reduc- is not any concrete removed.
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tions permitted by Tables R608.7(2), R608.7(3) and R608.7.2.1 Minimum length of solid wall segment
R608.7(4) are cumulative. and maximum spacing. Only solid wall segments equal
The total length of solid wall segments, TL, in a wall to or greater than 24 inches (610 mm) in length shall be
line that comply with the minimum length requirements included in the total length of solid wall required by Sec-
of Section R608.7.2.1 [see Figure R608.7(1)] shall be tion R608.7.1. In addition, not more than two solid wall
equal to or greater than the product of the unreduced segments equal to or greater than 24 inches (610 mm) in
length of solid wall from Tables R608.7(1A) through length and less than 48 inches (1219 mm) in length shall
(1C), UR and the applicable reduction factors, if any, be included in the required total length of solid wall. The
from Tables R608.7(2), R608.7(3) and R608.7(4) as maximum clear opening width shall be 18 feet (5486
indicated by Equation R6-1. mm). See Figure R608.7(1).
TL ≥ R × R × R × UR (Equation R6-1) R608.7.2.2 Reinforcement in solid wall segments.
1 2 3
where: R608.7.2.2.1 Horizontal shear reinforcement.
TL = Total length of solid wall segments in a wall Where reduction factors for design strength, R ,
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line that comply with Section R608.7.2.1 [see from Table R608.7(4) based on horizontal and verti-
Figure R608.7(1)]. cal shear reinforcement being provided are used,
solid wall segments shall have horizontal reinforce-
R 1 = 1.0 or reduction factor for mean roof height ment consisting of minimum No. 4 bars. Horizontal
from Table R608.7(2). shear reinforcement shall be the same grade of steel
R 2 = 1.0 or reduction factor for floor-to-ceiling wall required for the vertical reinforcement at the ends of
height from Table R608.7(3). solid wall segments by Section R608.7.2.2.2.
R 3 = 1.0 or reduction factor for design strength from The spacing of horizontal reinforcement shall not
Table R608.7(4). exceed the smaller of one-half the length of the solid
UR = Unreduced length of solid wall from Tables wall segment, minus 2 inches (51 mm), and 18
R608.7(1A) through (1C). inches (457 mm). Horizontal shear reinforcement
shall terminate in accordance with Section R608.6.4.
The total length of solid wall in a wall line, TL, shall
be not less than that provided by two solid wall seg- R608.7.2.2.2 Vertical reinforcement. Vertical rein-
ments complying with the minimum length require- forcement applicable to the reduction factor(s) for
ments of Section R608.7.2.1. design strength, R , from Table R608.7(4) that is
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used, shall be located at each end of each solid wall
To facilitate determining the required wall thickness,
wall type, number and grade of vertical bars at each end segment in accordance with the applicable detail in
of each solid wall segment, and whether shear reinforce- Figure R608.7(2). The No. 4 vertical bar required on
ment is required, use of Equation R6-2 is permitted. each side of an opening by Section R608.8.1.2 is
permitted to be used as reinforcement at the ends of
TL solid wall segments where installed in accordance
R ≤ -------------------------------- (Equation R6-2)
R × R × UR with the applicable detail in Figure R608.7(2). There
1
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shall be not less than two No. 4 bars at each end of
After determining the maximum permitted value of solid wall segments located as required by the appli-
the reduction factor for design strength, R , in accor- cable detail in Figure R608.7(2). One of the bars at
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dance with Equation R6-2, select a wall type from Table each end of solid wall segments shall be deemed to
R608.7(4) with R less than or equal to the value calcu- meet the requirements for vertical wall reinforce-
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lated. ment required by Section R608.6.
R608.7.2 Solid wall segments. Solid wall segments that The vertical wall reinforcement at each end of
contribute to the required length of solid wall shall comply each solid wall segment shall be developed below
with this section. Reinforcement shall be provided in the bottom of the adjacent wall opening [see Figure
accordance with Section R608.7.2.2 and Table R608.7(4). R608.7(3)] by one of the following methods:
Solid wall segments shall extend the full story-height
without openings, other than openings for the utilities and 1. Where the wall height below the bottom of the
other building services passing through the wall. In flat adjacent opening is equal to or greater than 22
walls and waffle-grid walls, such openings shall have an inches (559 mm) for No. 4 or 28 inches (711
2
area of less than 30 square inches (19 355 mm ) without mm) for No. 5 vertical wall reinforcement,
any dimension exceeding 6 / inches (159 mm), and shall reinforcement around openings in accordance
1
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not be located within 6 inches (152 mm) of the side edges with Section R608.8.1 shall be sufficient.
of the solid wall segment. In screen-grid walls, such open- 2. Where the wall height below the bottom of the
ings shall be located in the portion of the solid wall seg- adjacent opening is less than required by Item
ment between horizontal and vertical cores of concrete and 1, the vertical wall reinforcement adjacent to
the opening shall extend into the footing far

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