chap 4 Flashcards
building systems
continuous and unobstructed path of exit travel from any point in a building or structure to a public way
means of egress
stairs that usually connect 2 floors in a multistory building(NOT part of the means of egress )
An open set of stairs connecting two floors
convenience stairs
horizontal face of step
tread
VERTICAL PART of a stair step
riser
HORIZONTAL measurement of a stair tread or the distance of the entire stair length
run
VERTICAL distance b’tw the treads of a stairway, or the height of the entire stairway
rise p. 94
6 types of stairs
straight run , return , scissor, circular, folding and spiral
Intermediate landing b’tw floors and reverse direction at that point( common in modern construction).. May have more than one landing, where the height between floors is greater than normal. This type of stair design is common and modern construction..
return stairs p.95
2 separate sets of stairs constructed in common shaft( cheaper and space efficient ) Often used in assembly building that have large floor to ceiling height
scissor stairs
Often found as grand stairs or convenience stairs serving only 2 levels.. the minimum width of the run is usually 10 inches a special requirement is that small radius full circles is greater than twice the width part of the stair tread
This type of stair design is constructed as a sweeping curve and often used for grand entries and convenience stairs in upscale offices.
found in airports , convention centers, cinema and malls
circular stairs p.96
Series of steps spiraling around singe column to fit in a very small space ( primarily used in residential occupancy.. Each tried is tapered and connectS to the column(baluSTER) at the treads narrowing end.. Primarily used in residential occupancies for limited use.. because they are difficult to traverse ‘’ stairs are generally allowed as part of the means of egress only within residents.. steel ‘’ stairs are sometimes used for access to permit required confined space as well as dry wells and a sewage pump station and an industrial applications..
spiral
Actually ladders used to provide access to an attic.. Most commonly found in residential occupies.. Often located away from the buildings usual functional spaces.. usually have three wooden sections …
folding stairs p.97
extend in 1 direction for entire length.. landings may be used between sections or vertical travel.
straight run
’’’’ stairs as a component of the required means of egress, must meet strict requirements to ensure safe passage during buildings evacuation. this includes:
fire- resistance rating of the enclose
separation when exterior stairs are utilized
features to ensure safety during both nonemergency and emergency use
exit
What stairs must resist the effects of the products of combustion
Protected stairs
Measures indicated in building codes to ‘’’ stair enclosures include:
Limited penetrations in the enclosure for light, fire protection and environmental control
required self or automatic closing fire rated doors
separation from the rest of building
stairway vestibules
protect stair
stairs separated from interior of a building by walls
exterior stairs p. 98
fire escapes are fully anchored to the building, and the anchor points may fail w/o warning due to ?
damage from freeze- thaw cycle
corrosion from pollution and weather
inadequate mortar holding the anchors
active vs passive fire protection
A- moving mechanical or eletric parts that work as a system and require power ( fire alarm )
P- no system activation or movement relies on building construction ( fire walls ) p. 99
building code typically allows the use of open stairs in building only when they connect
no moe that 2 adjacent floors above basement level
system used to transport items and materials
conveyor system
conveyors systems often penetrate fire barriers, and are protected by features such as:
FD
S
S
fire doors , shutters and water spray fixed fire suppression system
Safeguards against incomplete ‘’’ include:
auto stop controls
breaks in conveyor
multi layers of doors or shutters
closure
Conveyor transport devices alined as a stair way with electrically powered steps that move in 1 direction
escalators p. 101