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Stairs provide dual roles, What are they?
A means of egress and access to different levels
6 types of stairs and describe
- Straight run- straight line entire length; may have landings
- Return stairs- intermediate landings; reverse direction
- Scissor stairs-2 separate stairs in common shaft
- Circular stairs- found as Grand stairs, or convenience connecting 2 levels, w 10"
- Folding stairs- attics
- Spiral stairs- allows stairs in a very small space, each tread tapered connected on narrow end
Stairs as a means of egress
Describe: exterior stairs
exterior and open to air, maybe partially enclosed from weather, atleast 1 side open
Describe fir escapes
open metal stairs and landings, not permitted for decades
Describe Smokeproof enclosure
buildings have requirement of 1 smokeproof enclosure stairwell on buildings 5+ stories and more recently levels more than 30ft below grade
Active smokeproof enclosure
mechanical air handling system(fans) designed to keep smoke out by pressuring the shaft
Passive smokeproof enclosure
Accessed by a vestibule or balcony; pprovides protection w/ a means for smoke to be vented to the outside before it enters the stair enclosure
What are open stairs?
Typically allowed only when they connect no more than 2 adjacent floors above the basement level. Can be used as means of egress in a 2 story dwelling
2 elevator types
- Hydraulic and Electric
- Hydraulic max height used is 6 stories
- 2 types of electric- drum and traction
- drum is older and uses a drum which winds the hoist cable
- traction is most common, fast has hoist cable but not wound
Elevator safety features(5)
- Terminal device- terminates power; stops car
- Buffers- large springs or hydraulic cylinders; act as shock absorbers
- Speed regulator switch- speed govenor
- Overspeed switch- activated if speed regulator switch fails
- Car safeties- tapered sets of steel jaws that wedge against the car on guide rails and bring car to a stop
Elevator hoistways usually required to have ___FRR, if building has 3 or fewer elevators codes require ___ hoistways and if greater than 3 stories requires ___ hoistways
- Usually requires 1 or 2 hr rating
- 3 or fewer elevators= 1 hoistway
- 4 or more elevators= minimum of 2 hoistways
- If building has multiple hoistways up to 4 elevators may be allowed in one hoistway
What is a blind hoistway?
On tall high rise buildings elevators have zones. Blind hoistways have elevators service top most zone
Moving stairs/walk ways speed?
usually either 90 fpm or 120 fpm now standard is 100 fpm
Vertical shafts/utility chases
describe: vertical shaft, utility chase, pipe chase, refuse/laundry, grease ducts
- Vertical shafts=stairwells, elevators etc...
- utility chase=contains plumbing, electrical etc...
- pipe chase= piping for hot and cold water, spinkler etc.
- grease ducts-
In general a fire or smoke damper may be required whenevr a duct penetrates a fire rated assembly
NFPA 90 requires that the HVAC enclosure be a ___hr FRR for buildings less than 4 stories and ___ FRR for buildings greater than 4 stories
- 1hr less than four stories
- 2hr greater than 4 stories
Smoke control systems are a means to control smoke thru use of mechanical fans to produce pressure differences across smoke barriers to inhibit smoke movement
2 types: automatic and manual; describe
- automatic- accomplished by smoke detectors
- manual- transfer valve to fire mode; adv eliminating system disruption due to false alarms; disadv slower response
There are 2 methods that can be used to protect an enclosed stairway
1. smokeproof tower; describe
2. Pressurized stairwell; describe
- smokeproof stairwell- makes use of a vestibule between corridor and the stairwell that is open to the atmosphere where smoke is exhausted
- pressurized- uses a blowe or fan to provide a slightly greater pressure in the stairwell than the corridor to prvent infiltration of smoke.
- 2 types single injection and multiple injection
What are curtain boards?
- Used in conjunction with smoke vents to increase effectiveness. Hung from ceiling. These reduce the dissipation of the heated air currents froma fire and increase speed of operation of vents
- *should not be placed further than 8x the ceiling height
High voltage is defined as? Low voltage?
What is the FRR if a transformer room is inside the building, with autosprinklers? and without auto sprinklers?
- High voltage is greater than 600 volts; low is less than 600 volts
- FRR of transformer room without autosprinkler 3hr
- if it has automatic sprinkler 1HR FRR
Generators are limited to how gallons of diesel?
What are things classified as interior finishes?
- Exposed interior surfaces of buildings including fixed or movable walls, partitions, columns and ceilings
- * bulding codes exclude surface treatments no greater than 1/28"
What are the class ratings of interior finishes?
- Class A 0-25= materials with this rating are required in the vertical exits of most occupancies
- Class B 26-75 Are required in corridors that provide exit access
- Class C 76-200
Common fire retardent coatings (4)
- Intumescent paints- expand when exposed to heat to thick puffy coating
- mastics-similar to intumescent but organic materials used
- gas forming agents
- cementious and mineral fiber coatings
Firewalls must extend beyond walls and roofs to revent padiant heat of flames. Parapet wall height must be _____
- Interior walls used to subdivide a floor or area
- partitions in exit corridor may require 1HR FRR
- also 1HR FRR if separating apartment units, commonly done by use of gypsum board or each side of steel studs
Enclosure and Shaft walls FRR?
- Stairwells in buildings 3 stories or less require 1 HR FRR
- stairwells taller than 3 stories or more require 2HR FRR
What are curtain walls?
- serve to enclose a building when it provides no structural support. Designed to separate interior from wind, rain, and snow and rain
- Also to control heat loss, noise transmission, and solar radiation
Fire Doors FRR? (7)
Fire door ratings are 4HR, 3HR, 1 1/2HR, 1HR, 3/4 HR, 1/2 HR, and 20 mins
What are the classes of fire doors under the old system?(A-E)
- Class A openings in firewalls
- Class B openings in vertical shafts and openings in 2HR rated partitions
- Class C openings in between rooms and corridors FRR 1 HR or less
- Class D openings in exterior walls subject to severe fire exposure from the outside
- Class E openings in exterior walls subject to moderate fire exposure from the outiside
Glazing and Fire Doors
Doors with up to ___HR FRR can have glass panels
Fire doors with 1, 1 1/2, and 3HR ratings ccan have glass panels up to ___
Fire doors rated at 3/4 can have a total glass area consistent with their listing but individual pieces cannot exceed _____
- 1. 3HR
- 2. 100 sq inches
- 3. 1296 sq inches
Types of Fire doors describe
Rolling steel fire doors
Horizontal sliding doors
Swinging fire doors
Special fire doors
- Rolling steel fire doors- on overhead rolling door ordinarily closes under the force of gravity when a fusible link melts but moror driven also available
- Horizontal Sliding doors- These doors are usually held open by a fusible link and SLIDE into position along a track either by gravity or by counterweight
- Swinging fire doors- very common for stairwell enclosures and corridors; avail in ratings of 3HR to 20 mins
- Special- horizontal has been developed with motor
Builder's hardware and fire door hardware difference?
FD assembly normally shipped with the door