Figure 4-l8.Joint finishes.
Figure 4-19.Common arch shapes.
supports must not only be able to support the masonry
during construction but also provide the geometry
necessary for the proper construction and appearance
of the arch. Such supports are called templets.
Figure 4-20.Using a template to construct an arch.
DIMENSIONS. Construct a brick arch over the
templet (fig. 4-20) that remains in place until the
mortar sets. You can obtain the templet dimensions
from the construction drawings. For arches spanning
up to 6 feet, use 3/4-inch plywood to make the templet.
Cut two pieces to the proper curvature, and nail them
to 2 by 4 spacers that provide a surface wide enough
to support the brick.
POSITIONING. Use wedges to hold the
templet in position until the mortar hardens enough to
make the arch self-supporting. Then drive out the
Lay out the arch carefully so that you dont have
to cut any bricks. Use an odd number of bricks so that
the key, or middle, brick falls into place at the exact
arch center, or crown. The key, or middle, brick is the
last one laid. To determine how many bricks an arch
requires, lay the templet on its side on level ground and
set a trial number of bricks around the curve. Adjust
the number of bricks and the joint spacing (not less
than one-fourth inch) until the key brick is at the exact
center of the curve. Then mark the positions of the
bricks on the templet and use them as a guide when
laying the brick.
ESTIMATING BRICK AND MORTAR
When estimating the number of brick and the
quantity of mortar, you need to know the exact size of
the brick and the thickness of the mortar joint. This
information is found in the plans or specifications.
Table 4-5 shows the quantities of material required for
NOTE: Quantities of brick include the thickness
of the mortar joint and no allowance for waste.