the strength of walls constructed with cored brick
and those constructed with solid brick. Resistance
to moisture penetration is about the same for both
types of walls. The most easily available brick that
will meet the requirements should be used whether
the brick is cored or solid.
SAND-LIME bricks are made from a lean
mixture of slaked lime and fine silicious sand,
molded under mechanical pressure and hardened
under steam pressure.
Types of Bonds
When the word bond is used in reference to
masonry, it may have three different meanings:
STRUCTURAL BOND is a method of inter-
locking or tying individual masonry units together
so that the entire assembly acts as a single
structural unit. Structural bonding of brick and
tile walls may be accomplished in three ways: first,
by overlapping (interlocking) the masonry units;
second, by the use of metal ties embedded in
connecting joints; and third, by the adhesion of
grout to adjacent wythes of masonry.
MORTAR BOND is the adhesion of the joint
mortar to the masonry units or to the re-
PATTERN BOND is the pattern formed by
the masonry units and the mortar joints on the
face of a wall. The pattern may result from the
type of structural bond used or may be purely a
decorative one in no way related to the structural
bond. Five basic pattern bonds are in common
use today, as shown in figure 7-52. These are
running bond, common bond, stack bond,
Flemish bond, and English bond.
RUNNING BOND is the simplest of the basic
pattern bonds; the running bond consists of all
stretchers. Since there are no headers used in this
bond, metal ties are usually used. Running bond
is used largely in cavity wall construction and
veneered walls of brick and often in facing tile
walls where the bonding may be accomplished by
extra width stretcher tile.
COMMON or AMERICAN BOND is a
variation of running bond with a course of full-
length headers at regular intervals. These headers
provide structural bonding, as well as pattern.
Header courses usually appear at every fifth,
sixth, or seventh course, depending on the
structural bonding requirements. In laying out any
bond pattern, it is important that the corners be
started correctly. For common bond, a three-
quarter brick must start each header course at the
corner. Common bond may be varied by using
a Flemish header course.
STACK BOND is purely a pattern bond.
There is no overlapping of the units, all vertical
joints being aligned. Usually, this pattern is
bonded to the backing with rigid steel ties, but
when 8-in.-thick stretcher units are available, they
may be used. In large wall areas and in load-
bearing construction, it is advisable to reinforce
the wall with steel pencil rods placed in the
horizontal mortar joints. The vertical alignment
requires dimensionally accurate units, or carefully
prematched units, for each vertical joint align-
ment. Variety in pattern may be achieved by
numerous combinations and modifications of the
basic patterns shown.
FLEMISH BOND is made up of alternate
stretchers and headers, with the headers in
alternate courses centered over the stretchers
in the intervening courses. Where the headers are
not used for structural bonding, they may be
obtained by using half brick, called blind-headers.
Two methods are used in starting the corners.
Figure 7-52 shows the so-called FLEMISH
corner in which a three-quarter brick is used to
start each course and the ENGLISH corner in
which 2-in. or quarter-brick closures must be used.
ENGLISH BOND is composed of alternate
courses of headers and stretchers. The headers are
centered on the stretchers and joints between
stretchers. The vertical (head) joints between
stretchers in all courses line up vertically. Blind
headers are used in courses that are not structural
bonding courses. The English cross bond is a
variation of English bond and differs only in that
vertical joints between the stretchers in alternate
courses do NOT line up vertically. These joints
center on the stretchers themselves in the courses
above and below.
Specific terms are used
various positions of masonry
to describe the
units and mortar