4- Building Construction- Building Systems Flashcards
Most stairs provide a dual role as a building system. They enable access to multiple levels of a structure and they serve as a means of egress. Stairs that are NOT part of the means of egress are often referred to as _____ _____.
Convenience stairs
Tread = __?__
Riser = __?__
___ is the horizontal measurement of a stair tread
___ is the vertical distance between the treads
Run ; Rise
The components of prefabricated stairs are held together using ___ ___, which are known to fail under specific conditions, having been tested for applications including roof and floor joists.
Metal Gussets
_____ Stairs extend in one direction for their entire length. Landings may be used between sections of vertical travel.
Straight-Run
_____ Stairs have an intermediate landing between floors and reverse direction at that point.
Return
_____ Stairs are two separate sets of stairs constructed in a common shaft. Cheaper and more space efficient than two separate stair enclosures.
Scissor
_____ Stairs are often found as grand stairs or convenience stairs serving only two levels.
Circular
*Minimum width of the run is usually 10”
*Special requirement is that the small radius of the full circle is greater than or equal to twice the widest part of the stair tread
_____ Stairs consist of a series of steps spiraling around a single column to fit in a very small space. Each tread is tapered and connects to the column (baluster) at the tread’s narrow end. Typically NOT enclosed.
Spiral
_____ Stairs are actually ladders used to provide access to an attic space that does not have a permanent access stair. Most commonly found in residential occupancies and added after construction to provide attic access.
Folding
*Springs in folding stairs lose tension rapidly when exposed to heat, and the stair assembly may swing down into the structure during a fire. The opening can also provide a vertical path for fire and smoke spread.
Some types of exit stairs provide _____ but not _____, that is, they do not allow building re-entry onto any floor except the ground floor, for security reasons.
Egress ; Access
_____ stairs must resist the effects of the products of combustion.
Protected
_____ stairs are naturally ventilated on one or more sides.
Exterior
____ _____ include open metal stairs and landings attached to the outside of a building. The lowest flight may consist of a swinging stair section to limit unauthorized access. They have not been permitted in new construction for many decades, but many still exist.
Fire Escapes
Building codes have traditionally required a minimum of one smokeproof stair enclosure for stairs serving buildings ___ stories or higher. More recently, codes also require protection for stairs serving floor levels more than ___ feet below the level of exit discharge.
Five ; 30
____ fire protection uses moving mechanical or electrical parts that work as a system and require a power source for operation. Systems that may be linked directly into a building’s systems include automatic sprinkler systems and fire alarm systems. Other power sources may be manual, like portable fire extinguishers.
Active
____ fire protection does not require any system activation or movement. It relies on building construction and materials to contain fire or products of combustion. Examples include fire walls and stair enclosures.
Passive
Building codes typically allow the use of open stairs in buildings only when they connect no more than ___ adjacent floors above the basement level.
Two
Escalator speeds are standardized at ___ ft/min.
Older escalators usually operate at speeds of either __ or ___ ft/min.
100 feet/minute
Older ones speeds either 90 or 120 feet per minute
Vertical penetrations for escalators serving more than __ floors must be protected.
2
The most common protection for the vertical opening of escalators serving more than 2 floors is to use closely spaced ____ and ____ ____ around the opening.
Sprinklers ; Draft Stops
*Combined, they may be arranged as an 18” deep draft stop with a row of automatic sprinklers on all sides outside the draft stop.
Elevators are complex mechanical building systems with the following (four) features:
-Serves 2 or more levels or landings
-Includes hoisting and lowering mechanisms
-Provides access to above- or below-grade stories
-Uses a car or platform that moves along guide rail
Elevators can be classified according to their use:
(there are 3)
-Passenger (carry people)
-Freight (carry resources that may be bulky or heavy)
-Service (passenger elevators designed to also carry freight)
_____ elevators operate via fluid forced, under pressure, into a cylinder containing a piston or ram. They have no brakes; movement is controlled through the flow of the fluid.
Hydraulic
Four common styles of electric elevators are:
-Drum elevators (passenger use)
-Traction elevators (passenger use)
-Machine Room-Less (MRL) elevators (passenger use)
-Dumbwaiters (cargo use)
_____ elevators use a hoisting cable wound on a drum located in a motor room directly over the hoistway.
Drum
*drum elevators are obsolete and found only in very old structures or in use as freight elevators
______ are the most common type of elevators in buildings over six stories. They are fast and don’t have the height limitations of other types of elevators.
Traction
_____ are small freight elevators that move along a hoistway and transport items of small weight and size between floors. Historically, they were drawn with ropes and used to move food from a kitchen to upper floors.
Dumbwaiters
Passenger safety devices found on elevators may include:
-Terminal device
-Buffers
-Speed reducing switch
-Overspeed switch
-Car safeties
An elevator ______ is the vertical shaft in which the elevator car travels.
Hoistway
The elevator _____ extends down from the lowest floor landing to the bottom of the hoistway.
Pit
If an elevator hoistway is not vented at the top, the accumulated hot gases and smoke tend to _______, or spread horizontally into the upper floors.
Mushroom
A building with __ or fewer elevators may contain all of them in a single hoistway. __ or more elevators must have a minimum of two separate hoistways.
3 ; 4
Where more than one hoistway is provided, up to __ elevators may be located in one hoistway. Elevators that share a hoistway are not usually separated.
4
Blind hoistways are used for express elevators that serve the upper elevator zones in tall buildings. There will be no entrances to the hoistway on floors between the main floor and the lowest floor served. If a SINGLE-CAR hoistway is used, access doors will be provided for rescue purposes. Generally, these are placed every ____ floors.
Three
Doors in elevator installations include both __ doors and __ doors. The two are usually designed to open and close together, in the same direction.
Car ; Hoistway
A top exit is provided on all electric traction elevators. Some top panels are designed to be opened from inside the car, but all can be opened from outside and all open _____.
Outward
______ are required at the top of a refuse or laundry chute and in its termination room.
Sprinklers
A ___ ____ is a concealed vertical channel in which pipes and other utility conduits are housed. Ones that are not properly protected can be major contributors to the vertical spread of smoke and fire in a building.
Pipe Chase
Duct detectors are typically provided for fans with capacities exceeding ____ cubic feet per minute, to stop these systems under fire conditions and minimize unwanted smoke movement.
2000
Air ducts are the distribution component of HVAC systems. Building, mechanical, and fire codes contain the requirement that they have ___ dampers and ___ dampers to maintain the integrity of the fire-rated assemblies.
Smoke ; Fire
With a few minor exceptions, codes require that HVAC ducts in multistory buildings be enclosed in a fire-rated shaft enclosure. NFPA 90A requires that the enclosure be __hour rated for buildings less than 4 stories in height and __hour fire rated for buildings 4 stories or greater.
One ; Two
An HVAC system operating in “smoke control mode” discharges smoke through the exhaust fan from the fire floor to the outside without returning air to the supply fan. The continuance of supply of air to the non-fire floors creates a “pressure sandwich” of _____ air pressure on floors above AND below the fire floor.
Higher
The advantages of manual operation of HVAC smoke control include:
-Elimination of system disruption due to false alarms
-More specific system control
_____ _____ may be used in conjunction with smoke vents to increase their effectiveness. They reduce the dissipation of the heated air currents from a fire and increase the speed of operation of the vents.
Draft Curtains (curtain boards)
The depth of a curtain board will vary depending on the nature of the hazards within an occupancy, but should not be less than ___% of the ceiling height. Curtain boards should be spaced so that the are not farther apart than __ times the ceiling height.
20% ; 8x
High voltage electrical equipment is defined as operating at ___ volts or higher; low voltage equipment operates at less than ___ volts.
600
_____ convert high-voltage electricity from the electric utility service to an appropriate voltage for building systems use.
Transformers
When transformers are inside, codes require that the transformer rooms or vaults be enclosed in __ hour fire-rated construction if not protected by automatic sprinklers, or __ hour fire-rated construction with sprinklers.
3 ; 1
Fuel storage should be located separately from a generator. An exception is a day tank, which may be located in the same room or directly on the generator. Fire codes typically limit the tank to __ gallons for diesel fuel.
60
