recommended for use in spaces that may be
exposed to moisture during construction, but will
be covered when construction is complete.
Overlaid panels have a resin-treated fiber-
surfacing material, on one or both sides, to hold
paint and finishes more readily. These exterior or
interior types of plywood are recommended for
use in furniture, cabinets, millwork, and exterior
Decorative panels are used basically for
exterior and interior wall sheathing. Both types
are manufactured in a multitude of designs and
patterns and can be painted, stained, or left to
A concrete form panel has a coating over its
exterior face to make it moisture-resistant and
nonadhesive to concrete when used as forming
material. The exterior coating reduces the number
of times the form must be oiled and allows the
panel to be reused several times.
COMMON WOOD SUBSTITUTE
For various reasons, many common con-
struction materials are used as wood or plywood
substitutes. Some are significantly less expensive
than plywood; others are more suitable because
of their decorative appearance and weather-
Particleboard, commonly referred to as chip-
board or flakeboard, is produced by mixing a
resin-bonding agent with wood particles and
bonding them together by means of heat and
pressure. The use of particleboard is limited to
nonstructural use because of its low strength
qualities. The most common size sheets are 4 ft
by 8 ft and vary from 1/4 in. to 1 1/2 in. thick.
Hardboard is made of compressed wood fibers
subjected to heat and heavy pressure. The finish
may be obtained in a plain, smooth surface or in
any number of glossy finishes, some of which
imitate tile or stone. Its strength is about equal
in all directions, and it can be bent into various
shapes. Hardboard is available in thicknesses from
1/8 in. to 3/8 in. The most common size sheets
are 4 ft by 8 ft.
Fiberboard is made of wood or vegetable fiber
that has been compressed to form sheets or
boards. They are comparatively soft and provide
good insulation and sound-absorbing qualities.
Fiberboard is available in sizes from 1/2 in. to
1 in. thick, 2 ft to 4 ft wide, and 8 ft to 12 ft
Gypsum wallboard is composed of gypsum
between two layers of heavy paper. Some types
have unfinished surfaces, while others have
finishes that represent wood grain or tile. The
most common thickness is 1/2 in. Its width is
usually 4 ft, and its length varies from 4 to 14 ft.
Another type of gypsum wallboard has
depressed or tapered edges. The joints are filled
with special cement and are then taped so that the
joints do not show. They can then be painted. This
procedure is commonly known as DRY WALL.
Dry walls are particularly useful in areas and
spaces where sound-deadening and fire-resistant
materials are desired.
When not properly treated and installed, wood
can be destroyed by decay, fungi, boring insects,
weathering, or fire. Although designed for the
specific use of the wood, treatment varies from
project to project and from one geographical area
to another. The kind and amount of treatment
is usually given by the project specifications.
Where no written specifications exist, the
drawings should indicate the kind and amount of
Manufacturers commercial standards contain
information on wood pretreated by the manu-
facturer. NAVFAC publications and specifica-
tions provide technical information and design
requirements for the treatment of wood used in
buildings and structures.
WOOD FRAME STRUCTURES
In a wood frame building or structure, the
framework consists mostly of wood load-bearing
members that are joined together to form an
internal supporting structure, much like the
skeleton of a human body.
When a complete set of drawings is made for
a certain building, large-scale details are usually
shown for typical sections, joints, and other
unusual construction features. Understanding the
different functions of the structural members of
a frame building will enable you to make these
drawings correctly and promptly.
THEORY OF FRAMING
Generally, a building has two main parts: the
FOUNDATION and that part above the founda-
tion, called the SUPERSTRUCTURE. The