4. For steel framing, trace off or transfer the dimensions of all of the bearing walls, columns, and beams below the floor (or roof) being framed. Lay out the steel framing, using the grid system (a  common  setup  used  in  steel  framing). 5.  Lay  out  guidelines  for  dimensions,  notes, and labels. Darken in all of the framing and fill in the notes and dimensions. Draw in the section and detail marks. Go over your structural plans checklist and check the dimensions against those traced  from  the  floor  plan. MECHANICAL   DRAWINGS Refer to chapter 8 of this book to review the basic  functions  of  the  components  associated  with the mechanical systems and the methods used in the  development  of  a  mechanical  plan.  This section will focus on the procedures applicable in drawing  plumbing  plans  for  residential  and commercial   buildings. In  some  residences  and  commercial  structures, a  separate  mechanical  plan  is  drawn  to  show fixtures, water supply and waste disposal lines, equipment, and other supply and disposal sources. In   drawing   a   plumbing   plan,   the   following procedures  apply: 1.  Trace  the  floor  plan,  showing  all  exterior and   interior   walls,   major   appliances,   and plumbing  fixtures.  Orient  your  drawing  so  that enough  space  is  left  for  fixture  schedules,  legends, details,  or  other  related  information.  Note  that the outline of the building is drawn in thin but visible  lines. 2.  Draw  the  water-supply  line  from  the  source into  the  house,  and  then,  one  by  one,  to  all  of the  fixtures.  Use  the  appropriate  line  thickness  and symbols  for  drawing  valves,  fittings,  and  pipe sizes. Next, draw the disposal system. Start the layout with the house or building drain from just outside the building. Also, locate the waste and vent stack at this time. 3. Add a symbol legend, drawing title, notes, and scales, and fill in the title block. Go over and double-check  the  dimensions  and  the  checklist. As  you  can  readily  tell  from  figure  8-27  in chapter  8,  plumbing  plans  alone  can  become extremely difficult to read and fully comprehend. For this reason, it is general practice to prepare and include riser diagrams, such as those shown in  chapter  8,  figures  8-24  through  8-26.  These isometric  drawings  are  much  easier  to  understand and  are  invaluable  to  those  responsible  for preparing material estimates and to the craftsmen (UTs)  responsible  for  installing  plumbing  systems. As  alluded  to  in  chapter  8,  the  mechanical division  of  a  set  of  construction  drawings  will include, in addition to plumbing plans and details, drawings  for  any  heating,  ventilation,  and  air- conditioning   systems   that   a   building   might contain. Frequently,   the   drawing   sheets   in the  mechanical  division  are  identified  by  the designating letter  M in the title block. However, remember  that  in  the  order  of  drawings,  these sheets  containing  heating,  ventilation,  and  air- conditioning   drawings   will   precede   those   for plumbing. ELECTRICAL   DRAWINGS The  electrical  systems  and  plans,  as  described in chapter 9, consist of the basic functions of the components  associated  with  electrical  distribution and interior wiring and the methods used in the development  of  an  electrical  plan.  This  section, however,   emphasizes   the   procedures   used   in preparing  an  electrical  drawing  or  plan.  It  is important for an EA not only to understand the symbols  and  drafting  methods  used  here,  but  also to learn a great deal about how the system works, the  safety  of  the  system,  and  the  minimum requirements  of  local  and  national  codes  included in  the  drawing.    The  drawing  sheets  in  the electrical  division  of  construction  drawings  are frequently identified by the letter E in their title blocks. In drawing the electrical plan, follow the same approach used in the mechanical drawing, such as  using  the  correct  line  thickness  and  proper orientation. To the fullest extent possible, be sure, also,  to  use  the  standard  electrical  symbols discussed previously in the text. 1.  After  the  floor  plan  is  traced,  locate  the meter  and  service  panel,  noting  the  voltage  rating and the amperage. Locate all of the convenience outlets,  ceiling  and  wall  fixtures,  and  other electrical  devices  required  with  the  appropriate symbols. 2.  Locate  all  of  the  switches;  connect  the switches  to  the  fixtures  or  convenience  outlets, 10-26