(ANSI). However, many engineers will modify them to suit their needs. For this reason, most drawings have a symbol list or legend. The electrical 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 construction 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 showing 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.
The exterior elevation drawings show views of the finished exterior sides of the building. They show exterior trim, finish, window and door openings, 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.
The interior elevation drawings show views of inside wall space that contain counters, sinks, cupboards, and other special features. These drawings 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
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 exterior 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 proportional reductions of the final structure. The amount of reduction depends on the size drawing 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.
A bill of material (BM) is a tabulated statement of the material required for a given project. It contains information such as stock numbers, unit of issue, quantity, line item-number, description, 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 construction 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.Continue Reading