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Walls may
also be made of blocks, as we have detailed elsewhere, 4-inch-wide
blocks being the narrowest width recommended, 6-, 8-, 10-, and 12-inch-
wide blocks being adaptable to various walls for various purposes. Concrete may be cast as a wall, too, 4 to 6 inches being the narrowest it is
practical to cast for low walls. Above that, use any width that is practical
for your purpose. Block and concrete walls may be topped with a
soldier course of bricks (see Chapter XI), finished with coping blocks,
cut stone, or cast concrete to provide an overhang so that moisture does
not drip or run down the face of the wall. Bolts may be embedded in the
mortar or concrete so that wooden planks or other wooden seats may be
fastened to the top of the masonry wall. Providing the proper finish
to the top of the wall is important not only to the looks of the wall but
also to insure its durability. Walls of blocks or concrete may be veneered
on the face with bricks where they are used for low retaining walls.
Walls of waist height or higher which are of any length may require
the insertion of pilasters or piers every 10 feet. Intervals of 6 to 8 feet
would be safer with higher walls. The exception to this rule is the
serpentine wall, whose double curve, if based on a proper footing
and foundation, will withstand a great deal of stress and strain merely
by exerting opposing pressures of its own. A curved template or form
built of hardboard or thin plywood, bent to the proper radius, and
fastened to a wooden frame will be of assistance in building a serpentine
wall quickly and easily. Lay out the basic curves for the first course
on the foundation by using a stake and a cord and running an arc.
Where this arc joins the arc made from the opposing radial center,
the bricks or blocks are laid to join and then go in the opposite curve.
For taller serpentine walls deeper curves are needed than for low ones,
but for even shoulder-height walls a single-thick course of bricks is all
that will be necessary. If you have ever seen the beautiful serpentine
walls at the University of Virginia at Charlottesville, Va , which were
laid out by Thomas Jefferson, you know the truth of this statement.
If you wish to make wider serpentines, it is a good plan to run headers
to tie together the double or triple courses every four or five courses
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