FRAMING PLANS show the size, number,and location of the structural members (steel or wood) in the building framework. Separate framing plans may be drawn for the floors, the walls, and the roof.
The FLOOR FRAMING PLAN must specifythe sizes and spacing of joists, girders, and columns used to support the floor. Detail drawings must be added, if necessary, to show the methods of anchoring joists and girders to the columns and foundation walls or footings. The floor framing plan is basically a plan view showing the layout of the girders and joists. Figure 10-19 shows the manner of presenting floor framing plans. The unbroken double-line symbol indicates joists. Joist symbols are drawn in the position they will occupy in the completed building. Double framing around openings and beneath bathroom fixtures is shown where used. Bridging is also shown by a double-line symbol that runs perpendicularly to the joist. In the figure, the number of rows of cross bridging is controlled by the span of the joist; the rows should not be placed more than 7 or 8 ft apart. Hence, a 14-ft span may need only one row of bridging, but a 16-ft span needs two rows.
Dimensions need not be given between joists.Such information is given along with notes. For example, "2" by 8" joists @ 2' – 0" O.C." indicates that the joists are to be spaced at intervals of 2 ft 0 in. on center (O.C.). Lengths may not be indicated in framing plans; the overall building dimensions and the dimensions for each bay or distances between columns or posts provide such data. Notes also identify floor openings, bridging, and girts or plates.
The WALL FRAMING PLANS show thelocation and method of framing openings and ceiling heights so that studs and posts can be cut.
The ROOF FRAMING PLANS show theconstruction of the rafters used to span the building and support the roof. The size, spacing, roof slope, and all of the details are also shown in the plan. The roof framing plan is drawn in the same manner as the floor framing plan; rafters are shown in the same manner as joists. Figure 10-20 is an example of a roof framing plan for a wood-frame roof.
In a precast or cast-in-place concrete floorand roof framing, a structural plan should indicate, with symbols, the location of bearing walls, beams, and columns, and the direction and size of steel reinforcing bars, the direction of the span, and the size and thickness of required structural members. Figure 10-21 shows an example of a structural roof framing with schedules and general notes included. When preparing framing plans, follow the procedures outlined below.
1. For wood-frame construction, trace ortransfer the dimensions of the location of the exterior stud wall, and lay out the limits of the roof overhang. Next, lay out the roof framing by locating the ridgeboard first and then all of the required intersecting pieces.
2. When the floor framing plans are required,proceed to transfer dimensions of the foundation walls or footings. Lay out supporting girders and joists in their proper spacing. Notice any bearing wails, stairwells, and other openings when you are developing a second-floor framing plan.
3. For concrete framing, take a similarapproach. Lay out the dimensions of the bearing walls below the floor (or roof) being framed. Hence, you will need the foundation plan to draw the first-floor framing, and you will need the first-floor plan to draw the second-floor framing. Next, add the locations of the beams and columns and the direction of the span and size of the precast concrete or the reinforcing steel for the poured-in-place concrete.
Figure 10-19.-Example of a structural floor framing plan for a wood-frame construction.
Figure 10-21.-Example of a structural roof framing plan for a precast or a cast-in-place concrete construction.
4. For steel framing, trace off or transfer thedimensions 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.