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
