Page 293 - 2018_IRC

WALL CONSTRUCTION

TABLE R606.9 R606.12 Seismic requirements. The seismic requirements
ALLOWABLE COMPRESSIVE STRESSES FOR of this section shall apply to the design of masonry and the
EMPIRICAL DESIGN OF MASONRY
ALLOWABLE COMPRESSIVE construction of masonry building elements located in Seismic
CONSTRUCTION; STRESSES GROSS Design Category D , D or D . Townhouses in Seismic
a
2
1
0
COMPRESSIVE STRENGTH CROSS-SECTIONAL AREA b Design Category C shall comply with the requirements of
OF UNIT, GROSS AREA
Type M or S mortar Type N mortar Section R606.12.2. These requirements shall not apply to
Solid masonry of brick and glass unit masonry conforming to Section R610, anchored
other solid units of clay or masonry veneer conforming to Section R703.8 or adhered
shale; sand-lime or con- masonry veneer conforming to Section R703.12.
crete brick: R606.12.1 General. Masonry structures and masonry ele-
8,000 + psi 350 300
4,500 psi 225 200 ments shall comply with the requirements of Sections
2,500 psi 160 140 R606.12.2 through R606.12.4 based on the seismic design
1,500 psi 115 100 category established in Table R301.2(2). Masonry struc-
tures and masonry elements shall comply with the require-
c
Grouted masonry, of clay ments of Section R606.12 and Figures R606.11(1),
or shale; sand-lime or con-
crete: R606.11(2) and R606.11(3) or shall be designed in accor-
4,500 + psi 225 200 dance with TMS 402 or TMS 403.
2,500 psi 160 140 R606.12.1.1 Floor and roof diaphragm construction.
1,500 psi 115 100 Floor and roof diaphragms shall be constructed of wood
Solid masonry of solid con- structural panels attached to wood framing in accordance
crete masonry units: with Table R602.3(1) or to cold-formed steel floor fram-
3,000 + psi 225 200 ing in accordance with Table R505.3.1(2) or to cold-
2,000 psi 160 140 formed steel roof framing in accordance with Table
1,200 psi 115 100
R804.3. Additionally, sheathing panel edges perpendicu-
Masonry of hollow load- lar to framing members shall be backed by blocking, and
bearing units: sheathing shall be connected to the blocking with fasten-
2,000 + psi 140 120 ers at the edge spacing. For Seismic Design Categories C,
1,500 psi 115 100 D , D and D , where the width-to-thickness dimension of
2
1
0
1,000 psi 75 70 the diaphragm exceeds 2-to-1, edge spacing of fasteners
700 psi 60 55
shall be 4 inches (102 mm) on center.
Hollow walls (cavity or
d
masonry bonded ) solid R606.12.2 Seismic Design Category C. Townhouses
units: located in Seismic Design Category C shall comply with
2,500 + psi 160 140 the requirements of this section.
1,500 psi 115 100 R606.12.2.1 Minimum length of wall without open-
Hollow units 75 70
ings. Table R606.12.2.1 shall be used to determine the
Stone ashlar masonry: minimum required solid wall length without openings
Granite 720 640 at each masonry exterior wall. The provided percentage
Limestone or marble 450 400 of solid wall length shall include only those wall seg-
Sandstone or cast stone 360 320
ments that are 3 feet (914 mm) or longer. The maxi-
Rubble stone masonry: mum clear distance between wall segments included in
Coarse, rough or random 120 100 determining the solid wall length shall not exceed 18
For SI: 1 pound per square inch = 6.895 kPa. feet (5486 mm). Shear wall segments required to meet
a. Linear interpolation shall be used for determining allowable stresses for the minimum wall length shall be in accordance with
masonry units having compressive strengths that are intermediate between Section R606.12.2.2.3.
those given in the table. R606.12.2.2 Design of elements not part of the lat-
b. Gross cross-sectional area shall be calculated on the actual rather than
nominal dimensions. eral force-resisting system.
c. See Section R606.13. R606.12.2.2.1 Load-bearing frames or columns.
d. Where floor and roof loads are carried on one wythe, the gross cross- Elements not part of the lateral force-resisting sys-
sectional area is that of the wythe under load; if both wythes are loaded, the
gross cross-sectional area is that of the wall minus the area of the cavity tem shall be analyzed to determine their effect on
between the wythes. Walls bonded with metal ties shall be considered as the response of the system. The frames or columns
cavity walls unless the collar joints are filled with mortar or grout. shall be adequate for vertical load-carrying capacity
and induced moment caused by the design story
drift.
R606.11 Anchorage. Masonry walls shall be anchored to
floor and roof systems in accordance with the details shown in
Figure R606.11(1), R606.11(2) or R606.11(3). Footings shall
be permitted to be considered as points of lateral support.

268 2018 INTERNATIONAL RESIDENTIAL CODE ®
Copyrighted © 2017 by, or licensed to, ICC (ALL RIGHTS RESERVED); licensed to UL, LLC pursuant to License Agreement with ICC. No further reproductions authorized or distribution authorized.
ANY UNAUTHROIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT; AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.