As necessary, SECTIONS are used in each of the main divisions of construction drawings to show the types of construction required, the types of materials used, their locations, and the method of assembling the building parts. Although they may be used in each of the divisions, the most common sections are generally located in the architectural and structural divisions.

All properly prepared sections are important to those responsible for constructing a building. Perhaps the most important of all are WALL SECTIONS, such as those shown in figure 10-22. These sections, commonly drawn at a scale of 3/4 in. = 1 ft, and normally located in the structural division, provide a wealth of information that is necessary to understand the structural

Figure 10-22.-Examples of wall sections.

Figure 10-23.Development of a sectional view.

arrangement, construction methods, and material composition of the walls of the building. When a cutting plane is passed through the narrow width of a building, as shown in figure 10-23, a TRANSVERSE, or CROSSSECTION, is developed. Similarly, passing the cutting plane through the length of a building results in a LONGITUDINAL SECTION. These section, usually located in the architectural division, are used to clarify the building design and total construction process. Another example of a building section is shown in figure 10-24, view A. Often, transverse and longitudinal sections are drawn at the same scale as the floor plan. To show as much construction information as possible, it is not uncommon for staggered (offset) cutting planes to be used in developing these sections.

If the time and effort were spent to draw a separate section for each and every wall and part of a building, it would soon become apparent that many of these sections are completely identical. To reduce the time and effort required for drafting and to simplify the construction drawings, it is common practice to use typical sections where exact duplications would otherwise occur. An example of a typical section is shown in figure 10-24, view B.

For best results and to save time, you should make a sketch of the section before beginning the actual drawing. Always have your sketch checked by your leading petty officer or another experienced EA to make sure that your work is compatible with their concept of the design of the building.

When more than one section is placed on the drafting sheet, arrange the sections so that the first one is through the front of the building, the other sections, excluding the last, move progressively through the interior, and the last one is through the back. This way, when the sections are finished, they give the user an orderly construction "tour" through the building. The following procedures will guide you in the development of a section:

1. After having selected the appropriate scale, lay out the first section lightly. Next, lay out all the other sections, allowing enough space between them for notes and dimensions. Align the sections so that the same elevation is maintained and the sections relate to one another, as shown in figure 10-22. Again, maintain enough clearance for sub-titles and scale and enough room for your title block.

2. Lay out the guidelines for the material labels, leaders, and vertical dimensions.

3. Darken the section drawings, using a system such as starting at the top of the sheet and working down, then starting at the left and

Figure 10-24.-Types of sections.

You may add detail markings, if any, at this time.

4. Add material symbols. Some EAs prefer to place the symbols at the back of the sheet rather than in the front for neatness and fast access for erasure when a minor change or revision affects them. Place the title and scale below to complete the section drawing. Remember to go over your section checklist for accuracy and completeness.