Technology Education Department
Technical Drawing Program
- An elevation is a drawing that shows the client and the contractor
what the exterior of a structure looks like.
- Front, back, rightside, and leftside elevations are used
to show the vertical heights of the floors, ceilings, windows,
doors and ridge line; the materials used on the exterior walls,
window and door trims, fascia and roof; the orientation and type
of windows and doors; the amount of overhang; and the pitch of
the roof.
- Elevations can be created by using an "elevation layout"
that includes all of the vertical measurements: ground level,
top of foundation wall, top of sill plate, finished floor, spacing
of siding, top and bottom of windows, size of fascia, finished
ceiling height, shingle spacing, ridge heights, and top of chimney.
The "elevation layout" along with a floor plan are
used to project uniform elevation views.
- Front, back, rightside, and leftside elevations are drawn
or plotted at a scale of 1/4"=1'-0". The back,
rightside, and leftside elevations may be plotted at a scale
of 1/8"=1'-0" to conserve paper. Angled, curved or
partially hidden sides must be "developed" or "rotated"
as separate elevation views to show their true shape.
- Materials are shown using textured patterns, fills or hatching
and labeled with a leader and appropriate lettering.
- The ground line is usually 6" below a 4" thick
concrete slab floor and 16" to 18" below a wooden joist
and subfloor. The ground line must be 6" below the top of
the concrete foundation wall when a full basement is part of
the house.
- The floor thickness depends on the size of the floor joist
and the type of subfloor:
2x10 joists @ 16"O.C. with 3/4" tongue & groove
plywood measures 10"
2 x 12 joists @ 16"O.C. with 3/4" tongue & groove
plywood measures 12"
- The tops of windows should be aligned with the tops of doors
either 6'-8" or 7'-0".
- Wall heights of 8'-0", 9'-0" or 10'-0" are
increased by 1.5" to allow for ceiling and flooring materials:
.5" for drywall on ceiling, .375" to .5" for ceramic
or vinyl tile underlayments, .75" to 1.0" for marble
or stone, .375" to .75" for hardwood flooring or .25"
to 1" for padding and carpeting.
- Ceiling joists between the first and second floors are usually
2x12's with .75" T&G plywood for a total of 12"
of thickness.
- Rafters are usually 2x6's, 2x8's or 2x10's @ 16" O.C.
with .5" or .625" T&G plywood sheathing and asphalt
or cedar shingles and measure 6", 8" or 10" respectively.
- The ridge line is the highest point of the roof intersections.
- A gable roof has a single ridge running the length of a building
with the roof sloping in two directions.
- A hip roof has a shorter ridge with the roof sloping in four
directions.
- A shed roof slopes in one direction only.
- The pitch of a roof is usually expresses as the the amount
of "rise to run" in feet or inches:
3" or 4" in 12" for warm dry climates and ranch
or prairie style homes (example 3/12 pitch)
5" to 8" in 12" for wet climates and traditional
or colonial style homes (example 6/12 pitch)
12" to 18" in 12" for snowy climates and chalet
or A-frame style homes (example 12/12 pitch)
- Chimneys and furnace vents must extend 24" above the
ridge of the roof if within 10'-0" of the ridge. If the
chimney is over 10'-0" from the ridge, the top of the chimney
must be 24" above a point 10'-0" away from the center
of the chimney.
- The roof overhang is influenced by the style of the house,
the climate of the building site, the height of the walls, the
height of windows and doors and the slope or pitch of the roof.
- The overhang (measured at the bottom of the fascia) should
not be lower than the framing at the top of windows and doors.
A typical fascia is 6" to 7.25" in height and can
be made from wood, vinyl or aluminum.
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