Week 8
description
Transcript of Week 8
Week 8
Stairs and Fireplaces
Objectives• This chapter discusses stairs and
fireplaces: types, sizes, code requirements, design considerations, and how to draw them
• Residential applications are the primary focus of this chapter
Stairs• Form of vertical access• Stairs may be open, partially enclosed or
contained in a well• May be residential, commercial, indoor,
outdoor, built on site, or prefabricated• May be constructed of wood, concrete or
metal• All stairs share some common features
and must meet local code and accessibility requirements
Stair Features• Balustrade: assembly containing the
balusters, newel posts and handrail• Wall rail: handrail that is mounted on a wall
and supported by wall-mounted brackets instead of newels
• Headroom: clear vertical distance between the tread and the ceiling, measured linearly along a sloped plane
• Pitch: angle of the staircase; the rise divided by the run
Stair Features (cont’d.)
Figure 11.6 Residential staircase clearances and dimensions.
Stair Features (cont’d.)Rise: vertical distanceRun: horizontal distanceStairs, stairway, staircase, stairwell, flight: a series of steps or flights of steps used for passing from one floor or landing to another Landing: level rest area on a staircaseStringer: diagonal structural support for the steps
Stair Features (cont’d.)• Step: consists of riser and tread• Riser: vertical board at the front of the step• Tread: horizontal board at the top of the
step• Well opening: hole made in an upper floor
for stairway placement• Handrails and guards: help people steady
themselves and usually consist of a single rail installed at a specified height
Stair Features (cont’d.)
Figure 11.11 Step construction detail.
Non-Residential vs. Residential Code
Compliance• Handrails on residence landings must be
between 34" –38" high, measured from tread top to handrail top
• Handrails on commercial building landings must be a maximum of 42" high.
• Stairs must be at least 36" wide in residences and 44" wide in commercial buildings with occupancy over 50
Stair Types• Straight run stairs: have no turns but may
have a landing• L-shaped stairs: have a landing and a turn
– Used when there is not enough space for a straight-run
• Winder stair: L stair where the L-shaped turn is made with trapezoidal treads due to lack of space for a landing
• U-shaped or scissors stair: consists of two parallel flights
Stair Types (cont’d.)
Figure 11.18 Winder stairs.
Stair Types (cont’d.)
• Spiral stair: rises in a circle above a center point; used where there is little horizontal space available
• Circular stair: requires a lot of horizontal space– Steps are trapezoidal and rise along an
irregular curve or arc
Exterior Stairs• Designed with smaller riser heights and
wider treads than interior stairs• There should be a landing every 16 risers
on continuous stairs• Usually the same material used on the
deck or porch is used for treads, and a non-skid material can be used to cover them
Exterior Stairs (cont’d.)
Figure 11.31 Concrete, wood, and open-riser exterior stairs. Basement and exterior wood steps rarely require risers.
Stair Design• Consider the staircase’s potential use
when deciding how wide to make it• Minimum code requirements result in
steep, narrow stairs• Use several short landings • Avoid single steps to sunken rooms• Select handrails that complement the
staircase• A well-designed staircase follows given
formulae
Calculating How Many Stairs Are Needed
• Formulae– Two risers plus 1 tread = 24"–25"– Riser tread = 72"–77"– Riser tread = 17"–18"– Angle should be 30°–37°
• Know the total rise• Calculate the height and number of risers• Calculate the width and number of treads
Creating a Grid to Draw the Stairs
• Draw a rectangle, making the length the total run available and the height the total rise
• Divide one of the vertical lines into the number of risers needed
• Mark off all 19 increments and project these increments horizontally to the vertical lines
Creating a Grid to Draw the Stairs (cont’d.)
• Now divide one of the horizontal lines into the number of treads needed
• Mark off all 18 increments and project these increments vertically to the horizontal lines
• Darken the risers and treads
Creating a Grid to Draw the Stairs (cont’d.)
Figure 11.38 Drawing a stairs grid: step 6.
Ramps• Sloped surface whose purpose is to make
a building accessible • Landings are required at the top and
bottom, and their length must take into account any adjacent doors
• An entry platform should extend 18" beyond the handle side of the door to facilitate wheelchair use
• Any ramp that exceeds a 1:12 ratio must have at least one handrail
Fireplaces and Stoves
• Framed opening in a chimney that holds an open fire
• A stove is a free-standing external fireplace in a metal container
• All fireplaces share some common features and must adhere to building codes for proper build and installation
Fireplaces and Stoves (cont’d.)
Figure 11.50 Different fireplace styles.
Features• Chimney: vertical structure that carries
smoke and gas out of the room• Header: horizontal component over the
fireplace opening• Firebox: combustion chamber where the
fire is contained• Firebrick: heat-tempered brick• Surround: immediate border of the face
around the firebox opening or a non-combustible/masonry decorative frame
Features (cont’d.)• Opening: rectangular recess in the
surround• Hearth: floor of the fireplace.• Mantel: whole frame surrounding a
fireplace• Vent: opening that draws air into the fire
and allows combustion byproducts to escape
Fireplace Styles
• Site-built: built on a masonry foundation and is usually rectangular with one, two, or three open faces
• Prefabricated: has a metal shell and a brick-lined firebox and is insulated
• Insert: heating unit that fits inside existing fireplace to convert it into an efficient zone heater
Fireplace Styles (cont’d.)
Figure 11.58 Two-face opposite masonry fireplace.
Design Considerations• Purpose: to provide an aesthetic focal
point, a zone heater, or both• Placement: fireplace can occupy an
interior wall, an exterior wall, or a corner• Firebox opening size: important for
appearance and operation• Available fuel options: cordwood, wood
pellets, fire logs, natural gas, propane, oil, coal, and electricity
Summary
• Stairs and fireplaces are important building components
• Many styles and materials for each are available
• When choosing and placing them, you must consider technical considerations and building codes along with aesthetic, functional, and design criteria