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Section 4 Finishing
Summary
A stairway is a series of steps, each elevated
a measured distance, leading from one level of
a structure to another. Main stairways are often
constructed in a factory, then assembled on-site
by the carpenter. Stairways are either straight
run or winding (circular or elliptical). Stairway
components include the stringers that support
risers and treads, vertical risers between treads,
and the horizontal treads (steps). In a given
run of stairs, all treads must be the same size
to assure safe use. Risers must also be the same
size. A main stair should be wide enough for
two people to pass each other without contact.
The number of steps and risers is calculated
using the total rise (vertical height) and total
run (horizontal distance) occupied by the stairs.
Stairways that are open on one side require use
of a decorative enclosure that also supports a
handrail. This enclosure is called a balustrade
and consists of newels, horizontal rails, and
balusters. Balustrades are typically factory made
and shipped to the job site for installation by the
carpenter. Metal spiral stairways are available.
They are usually installed to save space. Disap-
pearing stair units fold into the ceiling. They
provide access to attic areas without consuming
space in the room below.
Test Your Knowledge
Answer the following questions on a separate piece of
paper. Do not write in this book.
1. The platform type of stairway includes
______ where the direction of the stair run is
usually changed.
2. The minimum headroom for a main stairway,
as specifi ed by FHA, is ______.
3. One of the rules used to calculate riser-tread
relationship states that the sum of two risers
and one tread should be ______.
4. The front edge of the tread that overhangs
the riser is called the ______.
5. A stairs in a split-level home has six risers
with a tread width of 11″. The total run of the
stairs is ______.
6. A semihoused stair stringer is formed by
attaching a(n) ______ stringer to a backing
stringer.
7. True or False? Winder stairs are allowed by
all building codes.
8. ______ are glued and driven into the stringer
to assemble risers and treads in housed
stringers.
9. The three principal members of a balustrade
are the newels, rails, and ______.
10. When a disappearing stair unit is used to
provide attic access, the attic fl oor should be
designed for ______ fl oor loading.
Curricular Connections
Social Studies. The Dutch artist M.C. Escher
created a number of drawings featuring
stairways that were optical illusions—they
led nowhere but back to themselves. Use the
library or Internet to view several Escher
stairway prints. Try to determine how he
achieved the optical illusion. Also, search for
ways that other artists have featured stair-
ways in their paintings or photographs. See
how many different kinds of stairways you
can fi nd depicted. If possible, determine why
the artist made the stairway the focal point
of the work.
Outside Assignments
1. Obtain a set of architectural plans where
the main or service stairway is not drawn
in detail. Carefully study the stair require-
ments and then prepare a detail drawing
similar to Figure 18-12. Use a scale of 1/2″
equals 1′. Carefully select and calculate the
riser-tread ratio. Be sure the number and size
of risers is correct for the distance between
the two levels. Check the headroom require-
ments against your local building codes and
determine the stairwell sizes. Submit the
completed drawing and size specifi cations
to your instructor.