Building Construction Chapter 4

Stairs in a Building

• Stairs provide a means of vertical transportation and access between floors.

Types of Stairs

• Convenience stairs: secondary stairs that provide access to floors, but are not a primary means of egress.
• Scissor stairs: often found in industrial or commercial settings, where space is limited.
• Spiral stairs: typically found in smaller areas, such as residences or secondary spaces.
• Circular stairs: minimum width of the run is not specified, but it depends on the size and shape of the staircase.
• Folding stairs: can be folded up to save space when not in use.
• Straight run stairs: have a single, straight flight of stairs.

Fire Escapes and Stair Enclosures

• Fire escapes: a means of escape in case of emergency, often found on the exterior of a building.
• Smoke-proof stair enclosures: minimum requirement in more recent building codes is to provide a smoke-proof enclosure for stairwells.

Escalators and Elevators

• Escalators: typically set at a standard speed.
• Stairs as a means of egress: a key requirement is to provide a safe and accessible route for occupants.
• Elevators: characteristic feature is vertical transportation of people or goods.
• Freight elevators: carry resources that may be bulky or heavy.
• Hydraulic elevators: use a ram or piston with pressurized hydraulic fluid.
• Dedicated elevator car use for firefighters: allows firefighters to access a building quickly and safely during emergencies.

Elevator Systems

• Traction elevators: may require a high-voltage power supply when operating at great heights.
• Elevator motor: directly aids in stopping the car at the correct floor during normal operations.
• Dumbwaiters: commonly used for transporting small items, such as food or supplies.

Building Systems

• HVAC systems: primary purpose is to provide heating, ventilation, and air conditioning.
• Elevator hoistway enclosures: in tall buildings of reinforced concrete, typically constructed with a fire-resistant material.
• Blind hoistways: in tall buildings, provide a separate shaft for elevators, allowing for easier maintenance and upgrades.
• Compensated system: in pressurized stairwells, helps to maintain a consistent air pressure.

Safety and Emergency Systems

• Smoke control mode: manual activation typically occurs during a fire emergency.
• Duct detectors: primary function is to detect smoke and fire in HVAC systems.
• Overpressure relief: in a stairwell, achieved through the use of relief vents or doors.
• High voltage electrical equipment: defined as equipment operating at 600 volts or higher.
• Low voltage equipment: defined as equipment operating at 600 volts or lower.
• Oil-filled transformers: primary function of oil is to cool and insulate the transformer.
• Older cooling oils in transformers: contain hazardous materials, such as PCBs, which require labeling and special handling.