(ANSI). However, many engineers will modify
Sectional or Detail Drawings
them to suit their needs. For this reason, most
drawings have a symbol list or legend. The elec-
trical symbols in figure 4-2 are taken from the
ANSI Y32.9, 1972 publication.
With a thorough knowledge of blueprint
language (symbols, abbreviations, and lines), you
will be able to extract the information that is
provided on the different prints. Types of con-
struction drawings you should be familiar with
are discussed in the following sections.
The plot plan is the starting point for any
building that is to be constructed. It shows where
the building is to be placed on the plot of land
or property and shows the shapes and dimensions
of the plot. When the plot plan is bounded by
streets or drives, such information is also shown.
The plot plan aids the Utilitiesman by show-
ing the point where the service taps from a main
are to be connected or what route the pipe will
need to be run for an underground service.
Exterior Elevation Drawings
The exterior elevation drawings show views of
the finished exterior sides of the building. They
show exterior trim, finish, window and door open-
ings, roofing, and brickwork. Finished grade lines
and floor lines are also shown. You may find this
information helpful in locating outside wall
hydrants or hose bibs.
Interior Elevation Drawings
The interior elevation drawings show views of
inside wall space that contain counters, sinks, cup-
boards, and other special features. These draw-
ings can be of great help in determining where to
place rough-in piping for water or drainage
systems in kitchens and bathrooms. The material
that is to be used for walls also affects the
distance from the finished wall that the through
floor drainage or water supply will be roughed
in to (water closets, floor drains, and so forth).
Sectional or detail drawings are often inserted
into drawings to show a specific detail. They may
be a cross-sectional view of the building supports
or foundation. They could be used to show story
height and ceiling height. They may be used to
show what floors are made of, whether they have
wooden joists or some other type of construction.
Any of these factors might influence the method
of doing mechanical work and the kind of
material that is to be used.
A floor plan drawing is used to show exactly
what the name implies, a plan of the floor. The
drawing includes the layout of all interior and ex-
terior walls, including windows and doors. It also
shows all fixture requirements. A typical floor
plan is shown in figure 4-3.
All the drawings mentioned thus far are pro-
portional reductions of the final structure. The
amount of reduction depends on the size draw-
ing desired. Dimensions in feet are reduced to
parts of an inch; for example, 1 foot may be
reduced to 1/4 inch or 1/8 inch. The reduction
is called the scale of the drawing. If the scale of
a drawing is 1/4 inch = 1 foot, a 1-inch line would
represent 4 feet on the actual structure.
BILL OF MATERIAL
A bill of material (BM) is a tabulated state-
ment of the material required for a given project.
It contains information such as stock numbers,
unit of issue, quantity, line item-number, descrip-
tion, vendor, and cost. Sometimes the bill of
material will be submitted on either material
estimate sheets or material takeoff sheets; each
contains similar information. Actually, a bill of
material is a grouped compilation based on the
takeoffs and the estimates of all the materials
needed to complete a structure. Usually, the
takeoff sheet is an actual tally and checkoff of
the items shown, noted, or specified on the con-
struction drawings and specifications.
Most NAVFAC drawings will contain a bill
of material incorporated within the drawings. But,
there are times when you are directed to tabulate
materials needed for a new project that has been
designed in-house for cost estimating and funding.