Use of Symbols UNIT. Objectives. Door and Window Symbols

Transcription

1 UNIT Use of Symbols An alphabet of lines allows for clear communication through drawings; the use of standard symbols makes for even better communication. Many features of construction cannot be drawn exactly as they appear on the building. Therefore, standard symbols are used to show various materials, plumbing fixtures and fittings, electrical devices, windows, doors, and other common objects. Notes are added to drawings to give additional explanations. It is not important to memorize all the symbols and abbreviations used in construction before you learn to read drawings. You should, however, memorize a few of the most common symbols and abbreviations so that you may learn the principles involved in their use. Additional symbols and abbreviations can be looked up as they are needed. The illustrations shown here represent only a few of the more common symbols and abbreviations. A more complete reference is given in the Appendix. Door and Window Symbols Door and window symbols show the type of door or window used and the direction the door or window opens. There are three basic ways for household doors to open swing, slide, or fold, Figure 5 1. Within each of these basic types Objectives After completing this unit, you will be able to identify and understand the meaning of the listed symbols: Door and window symbols Materials symbols Electrical and mechanical symbols Reference marks for coordinating drawings Abbreviations Figure 5 1. Types of doors and their plan symbols. Use of Symbols 25

2 Openmirrors.com Figure 5 2. Window symbols. 26 Unit 5

3 there are variations that can be readily understood from their symbols. The direction a swing-type door opens is shown by an arc representing the path of the door. There are seven basic types of windows. They are named according to how they open, Figure 5 2. The symbols for hinged windows awning, casement, and hopper indicate the direction they open. In elevation, the symbols include dashed lines that come to a point at the hinged side, as viewed from the exterior. The sizes of windows and doors are usually shown on a special window schedule or door schedule, but they might also be indicated by notes on the plans near their symbols. Door and window schedules are explained later. The notations of size show width first and height second. Manufacturers catalogs usually list several sets of dimensions for every window model, Figure 5 3. The glass size indicates the area that will actually allow light to pass. The rough opening size is important for the carpenter who will frame the wall into which the window will be installed. The masonry opening is important to masons. The notations on plans and schedules usually indicate nominal dimensions. A nominal dimension is an approximate size and may not represent any of the actual dimensions of the unit. Nominal dimensions are usually rounded off to whole inches or feet and inches and are used only as a convenient way to refer to the window or door size. The actual dimensions should be obtained from the manufacturer before construction begins. Material Symbols The drawing of an object shows its shape and location. The outline of the drawing may be filled in with a material symbol to show what the object is made of, Figure 5 4. Many materials are represented by one symbol in elevations and another symbol in sections. Examples of such symbols are concrete block and brick. Other materials look pretty much the same when viewed from any direction, so their symbols are drawn the same in sections and elevations. When a large area is made up of one material, it is common to only draw the symbol in a part of the area, Figure 5 5. Some drafters simplify this even further by using a note to indicate what material is used and omitting the symbol altogether. Electrical and Mechanical Symbols Figure 5 3. Windows and doors can be measured in several ways. The electrical and mechanical systems in a building include wiring, electrical devices, piping, pipe fittings, plumbing fixtures, registers, and heating and air conditioning ducts. It is not practical to draw these items as they would actually appear, so standard symbols have been devised to indicate them. The electrical system in a house includes wiring as well as devices such as switches, receptacles, light fixtures, and appliances. Wiring is indicated by lines that show how devices are connected. These lines are not shown in their actual position. They simply indicate which switches control which lights, for example. Outlets (receptacles) and switches are usually shown in their approximate positions. Major fixtures and appliances are shown in their actual positions. A few of the most common electrical symbols are shown in Figure 5 6. Mechanical systems plumbing and HVAC (heating, ventilating, and air conditioning) are not usually shown in much detail on drawings for single-family homes. However, some of the most important features Use of Symbols 27

4 Openmirrors.com PLAN AND SECTION SYMBOLS EARTH ETC. CONCRETE EARTH ROCK STONE FILL METAL REINFORCING BARS STRUCTURAL CONCRETE LT. WEIGHT CONCRETE BLOCK STEEL, IRON ALUMINUM STRUCTURAL STEEL STONE PLYWOOD FINISH ROUGH STUD WALL & PARTITION CUT STONE RUBBLE CAST STONE (CONCRETE) GYPSUM SLATE, BLUESTONE SOAPSTONE COMMON FACE FIRE BRICK ON COMMON INSULATION GLASS PLASTER ON MASONRY BLOCK METAL STUD & PLASTER PARTITION PLASTER BOARD & PLASTER PARTITION LOOSE FILL OR BATTS RIGID BOARD SHEET & PLATE ELEVATION SYMBOLS RUBBLE STONE SQUARED STONE RUNNING BOND MASONRY STACK BOND MASONRY SHEET METAL GLASS CONCRETE PLASTER SHINGLES BRICK CERAMIC Figure 5 4. Material symbols. Figure 5 5. Only part of the area is covered by the brick symbol, although the entire building will be brick. may be shown. Piping is shown by lines; different types of lines represent different kinds of piping. Symbols for pipe fittings are the same basic shape as the fittings they represent. A short line, or hash mark, represents the joint between the pipe and the fitting. Plumbing fixtures are drawn pretty much as the actual fixture appears. A few plumbing symbols are shown in Figure 5 7. Reference Marks A set of drawings for a complex building may include several sheets of section and detail drawings. These sections and details do not have much meaning without some way of knowing what part of the building they are meant to show. 28 Unit 5

5 Figure 5 6. Some common electrical symbols. Callouts, called reference marks, on plans and elevations indicate where details or sections of important features have been drawn. To be able to use these reference marks for coordinating drawings, you must first understand the numbering system used on the drawings. The simplest numbering system for drawings consists of numbering the drawing sheets and naming each of the views. For example, Sheet 1 might include a site plan and foundation plan; Sheet 2, floor plans; and Sheet 3, elevations. On large, complex sets of drawings, the sheets are numbered according to the kind of drawings shown. Architectural drawing sheets are numbered A-1, A-2, and so on for all the sheets. Electrical drawings are numbered E-1, E-2, and E-3. A view number identifies each separate drawing or view on the sheet. Figure 5 8 shows drawing 5 on Sheet A-4. Because most of the drawings for a house are architectural, and the drawing set is fairly small, letters indicating the type of drawing are not usually included. Instead, the views are numbered, and a second number shows on which sheet it appears. For example, the fourth drawing on the third sheet would be 4/3, 4.3, or 4-3. Numbering each view and the sheet on which it appears makes it easy to reference a section or detail to another drawing. The identification of a section view is given with the cutting-plane line showing where it is taken from. For example, the section view shown in Figure 5 9 shows the fireplace at the cutting-plane line in Figure Notice that the cutting-plane line in Figure 5 10 indicates that the section is viewed from the top of the page toward the bottom, with the Use of Symbols 29

6 Openmirrors.com Figure 5 7. Some common plumbing symbols. fireplace opening on the right. That is how the section view in Figure 5 9 is drawn. This numbering system is also used for details that cannot be located by a cuttingplane line. The drawing in Figure 5-11 is a typical wall section, meaning that it is typical of a section view of any outside wall. This typical wall section includes a callout referencing a detail drawing of the roof cornice or eave. The cornice detail is Drawing 4 on Sheet A-4 and is shown in Figure Notice that the detail faces the opposite direction from the typical wall section. That is because, being a typical section, not a specific section, it represents all exterior walls regardless of the direction they face. Abbreviations Drawings for construction include many notes and labels of parts. These notes and labels are usually abbreviated as much as possible to avoid crowding the drawing. The abbreviations used on drawings are usually a shortened form of the word and are easily understood. For example, BLDG stands for building. The abbreviations used throughout this textbook and on the related drawings are defined in the Appendix. 30 Unit 5

7 Figure 5 8. This is drawing 5 on Sheet A-4. Figure 5 9. This section view is drawing 2 on Sheet 5. Use of Symbols 31

8 Openmirrors.com Figure Plan for fireplace detailed in Figure 5 9. Figure The detail of this cornice is shown in drawing 4 on Sheet A-4, Figure Unit 5

9 Figure This is the detail of the cornice in Figure CHECK YOUR PROGRESS Can you perform these tasks? Identify window types by their symbols. Identify materials by their symbols. Identify the most common plumbing equipment by its symbols. Reference details by their symbols. Define several common abbreviations used on construction drawings. Identify the most common electrical equipment by its symbols. Use of Symbols 33

10 Openmirrors.com ASSIGNMENT 1. What is represented by each of these symbols? 2. What is meant by each of these abbreviations? a. GYP. BD. b. FOUND. c. FIN. FL. d. O.C. e. REINF. f. EXT. g. COL. h. DIA. i. ELEV. j. CONC. 3. Where in a set of drawings would you find a detail numbered 6.4? 4. Where in a set of drawings would you find a detail numbered 5/M 3? 34 Unit 5