[Sidenote: Great Importance]
In examining the bond in a brick wall, the eye naturally is first
attracted to the brick units as so many colored spots arranged in
different order so as to produce a certain pattern effect; but this
pattern effect in the brickwork depends very largely upon what
at first may be overlooked or disregarded, the mortar joint. The
mention of mortar suggests in the mind a very commonplace thing
which the workman mixes and carries in a hod to the bricklayer; but
it is concave one of the most important elements entering into the
beauty, as well as the strength, of a brick wall.
[Illustration: Fig. 57. Mortar Joints]
[Sidenote: Effect of Mortar Color]
When you consider that all the joints in brickwork, both vertical
or "head" joints, and horizontal or "bed" joints, are filled with
mortar weathered of one color or another, amounting on an average
to one-seventh of the wall, it is evident what a vital part they
play in the appearance of the entire wall surface. An artist will
tell you that this amount of color introduced into any surface will
greatly modify, by contrast or analogy, the general effect, so that
it is of the utmost importance, in selecting the sort of brick you
wish for your wall surface, that you also select the mortar joint.
[Sidenote: Three Elements Involved]
Three elements must be carefully considered in dealing with the
mortar joint: its color, its texture, and its size and kind. The
color of the mortar joint may be such as entirely to destroy the
beauty of the brick. On the other hand, if it is properly chosen,
it will bring out the fine shades and tones of the brick in such a
way as to enhance very greatly its natural beauty. Then, the mortar
joint has a certain texture which is produced either by finishing
it rough or smoothing it with the trowel or a tool made for that
purpose. This mere treatment of the surface of the mortar joint has
more to do with the appearance of the wall than one might at first
suppose. In addition to that, the size of the mortar joint, running
from a thin "buttered" joint up to an inch in width affects the
color relation of the whole surface; and the kind of joint, whether
cut flush, raked out, or tooled in various shapes, has a distinct
bearing on the whole effect (Fig. 57). In a word, do not neglect
the mortar joint, for it is one of the most important elements
that go to make up the beautiful fabric of the brick wall, in the
building of which there is deserved and required the exercise of a
fine discriminating taste.
All in all, what with the convenient units of stretcher and header,
each with its color and texture, you have a medium in the choice
of bond, mortar joint, and pattern for weaving the most charming
mosaic or tapestry effects into the wall surface, a possibility
offered by no other material than face brick.