20 Chapter Stair Construction. 20 Chapter Stair Construction.
-
Upload
baldwin-little -
Category
Documents
-
view
278 -
download
1
description
Transcript of 20 Chapter Stair Construction. 20 Chapter Stair Construction.
20 Chapter Stair Construction Objectives Identify the various
types of stairs.
Define basic stair parts and terms. Calculate the rise-run ratio,
number and size of risers, and stairwell length. Lay out stringers
for a given stair rise and run. Prepare sketches of the types of
stringers. List prefabricated stair parts that are commonly
available. Stairs Series of steps at elevated measured distances
leading from one level of structure to another Construction
requires high degree of skill Carriages are inclined supports that
carry treads and risers pics721/Shutterstock.com Types of Stairs
Two stair categories Stairs may be Service Main Closed
Open Combination of closed and open Platform Stairs Include
landings where direction is usually changed
L-type Double L-type U-type Often used in split-level houses
Straight Run Stairs Continuous from one floor level to another
without landings or turns Require long stairwell in floor above to
provide headroom Winding Stairs Have circular or elliptical
shape
Gradually change directions as they ascend from one level to
another Often require curved wall surfaces that are difficult to
build Usually found only in high-end homes Stair Parts Stairs are
basically sets of risers and treads supported by stringers Total
risers is always one greater than total number of treads Ideal
riser height is 7 Ideal tread width is 11 Stairwell Framing Timing
for stair constructions varies
Rough openings must be carefully laid out and constructed Trimmers
and headers in rough framing should be doubled Providing adequate
headroom is important Stair Design Mathematical relationship
between riser and tread is important All treads in stair run must
be same size Same is true of risers Widths and Handrails Stairs
should be wide enough to allow
Two people to pass without contact Furniture to be moved Handrails
are used on open stairways constructed with low partitions or
banisters pics721/Shutterstock.com Stair Calculations To calculate
number and size of risers and treads
Divide total rise by 7 to find number of risers Round to whole
number of risers Divide total rise by that number to determine unit
rise Number of treads is one less than risers Stairwell Length
Stairwell opening size must be known during rough framing
operations Amount of headroom required must also be known Add
thickness of floor structure Divide total vertical distance by
riser height Stringer Layout First determine riser height
Use framing square to lay out stringer Trim bottom end of stringer
to adjust riser height for tread thickness Pro Tip Be very accurate
in laying out stringers
Use sharp pencil or knife Make lines meet on edge of stock Use
stair gauges or clamp strip of wood to blade and tongue Treads and
Risers Thickness of main stair tread is generally 1 1/6 or 1 1/8
Vertical and sloping stair riser shapes are used Nosing is part of
tread that overhangs riser Basement stairs may be constructed with
open risers Types of Stringers Treads and risers are supported by
stringers solidly fixed to wall Built-up stringers Cut-out
stringers Housed stringers Stairs are often built as
fully-assembled units and taken to jobsite Top Tread Stairways
Winder Stairs May be useful where space is limited
Require full-size or carefully scaled layout plans Check local
building codes to see if winder stairs are allowed Open Stairs
Require decorative enclosure and support for handrail
Principal members of balustrade Newels Balusters Rails Balusters
are joined to stair treads or shoe rail Stock Stair Parts Available
in wide range of stock sizes
Ordered through lumber and millwork dealers Stringers are made in
two sections for easier shipping Spiral Stairways Eliminate framing
and save space
Available in aluminum or steel and in variety of designs Use of
spiral stairs is often restricted by building codes Spiral
Stairways Drawing Disappearing Stair Units
Can be purchased ready to install Operate through opening in
ceiling Swing up into attic space when not in use Ceiling opening
should be framed as ceiling joists are installed Rock Island
Millwork