vertical (last) or bottom (first) cut. The triangular
description of the method of framing a pipe through
blocks can also be cut from 2 x 6 or 8-inch stock.
the ridge. Where a roof jack is not used, the
sheathing and other wood should be at least 6 inches
from the pipe. If some type of insulation board is
available, the wood should be covered with this.
Figure 3-23 shows the pipe through the roof when the
slope is in one direction. The framing is placed as
stated above. In many cases stovepipes are carried to
the outside of the building through the side wall.
This eliminates flashing and waterproofing around
the pipe or roof jack (fig. 3-24). Here the sheathing
on the side is cut back 6 inches from the pipe and
some type of insulating material is used, if possible.
b. (1) Where stovepipes are carried
through the roof, roof jacks are used with flashing
attached (figs. 3-22 and 3-23). In most cases these
Figure 3-20. Built-up stair stringer.
are installed over the roof and nailed. Fibered tar
cement is used around the edges and over the nail
3-13. ELECTRICAL SYMBOLS
heads, and the roof jack is soldered to the stovepipe,
if practicable. If the roof jack is used on a metal roof,
A study of utility installation in TO buildings is
beyond the scope of this subcourse. But since the
it is soldered to the roof if practicable; otherwise, the
location and type of electrical wiring and fixtures are
tar cement is used around the edge after it has been
normally shown on plan views, you should be able to
nailed securely (fig. 3-23). Where no roof jack is
recognize the basic electrical portion of architectural
used, the hole is covered with a piece of sheet metal
drawings. Some of the most commonly used
which has a hole cut to the size of the stovepipe. The
symbols are shown in figure 3-21.
sheet metal is placed over the roofing at the bottom
edge, and under it at the top edge. Where a metal
3-14. FIRE PREVENTION
roof is used, the flashing is soldered to the roof or
fastened by means of tar cement.
Since fire is always a danger in TO structures,
stovepipe does not go through the roof but out
precautions must be taken to reduce this hazard. It is
through the wall, no flashing is required; only one
important to know where to insulate against intense
piece of sheet metal slightly larger than the wall
heat and how far wood framing must be placed from
opening, with a hole the size of the pipe is necessary.
stoves, stovepipes, flues, and chimneys, in order to
This is nailed over the opening in the wall (fig. 3-24).
(2) Where a stovepipe goes through the
a. Framing around stovepipes is of major
sheet metal, a hole must be cut. The best method is
importance to the carpenter in the theater of
to mark a circle on the metal 1/2 inch larger in
operations since stoves are the usual method of
diameter than the pipe, then make another circle on
heating buildings. The pipes are carried out of the
the inside with a diameter 2 inches less than the
building by several methods. Figure 3-22 shows how
diameter of the first. With a straightedge, draw lines
the pipe is carried through the ridge of the roof. Here
through the center of the circle from the outside.
the sheathing must be cut to form an opening at least
These marks should be from 1/2 to 3/4 inch apart
12 inches larger than the pipe. The stove, where
along the outer circumference. Cut out the center
possible, should be set so that the rafters need not be
circle, then cut to the outside
cut. The ceiling joists or tie beams must also be
considered. Figure 3-22 also presents a detailed