Fire Safety Chapter 7 Flashcards

Means of Egress Overview

• Refers to a safe, continuous path from any point in a structure to a public way.
• Composed of three basic elements: exit access, exit, and exit discharge.

Common Factors in Loss-of-Life Fires

• Locked or blocked exit doors, improperly designed or marked exits, and inaccessible exits contribute to fatalities.
• Inadequate fire protection systems, combustible materials, and overcrowded spaces are significant risks.

Components of Means of Egress

• Includes subsystems such as automatic sprinklers, fire-resistance-rated construction (doors and walls), exit signs, illumination, and handrails.
• The means must terminate in a public way or an area of refuge.

Area of Refuge

• Provides a temporary safe space for individuals unable to use stairways during an emergency.

Regulatory Codes and Standards

• Governed by NFPA 101 (Life Safety Code) and American with Disabilities Act (ADA) of 1990, ensuring accessibility and safety in public spaces.
• Exit design must meet ICC/ANSI 117.1 requirements for accessibility.

Exit Definitions

• Exit: Separated portion of a means of egress providing a protected travel route to the exit discharge.
• Exit Access: Path leading to the exit, including hallways and corridors.
• Exit Discharge: Portion between the exit and public way.

Horizontal Exits

• Provide egress between buildings or through fire barrier walls at the same level.
• Must not account for more than 50% of total exit capacity.
• Require fire walls or barriers with at least a 2-hour fire-resistance rating.

Smokeproof Enclosures

• Stairways designed to minimize smoke penetration, ensuring safer egress during fires.
• Can be made smokeproof through pressurization or mechanical ventilation.

Door Requirements

• Exit doors must open in the direction of travel toward the primary exit based on occupancy and load.
• Minimum clear width for exit doors in new buildings is 32 inches.

Panic Hardware

• Must operate with no more than 15 pounds force to release the latch and 30 pounds to set in motion.
• Alarms may activate when panic hardware is used, alerting staff.

Delayed Egress Systems

• Allow doors to unlock upon loss of power or activation of fire systems, with a maximum opening delay of 15-30 seconds.
• Must include clear labeling and audible alarms.

Securing Exits

• Security bars can impede emergency personnel, posing risks during emergencies.
• Doors must be designed to allow easy access for occupants while providing security from outside.

Fire Ratings and Wall Finishes

• Fire walls and barriers' ratings depend on building type and occupancy, impacting interior finish materials.

Stairway Specifications

• Minimum width for stairs in multistoried buildings is 44 inches, decreasing to 36 inches if the load is under 50 occupants.
• Landings are required for stair flights exceeding 12 feet in height.
• Handrails are necessary for stairways and may require intermediate railings for wide stairs.

Emergency Lighting and Signage

• Emergency lights need battery or auxiliary power.
• Markings should direct occupants to exits within 100 feet, with exit signs featuring specific size requirements for visibility.

Occupant Load Calculations

• Total number of persons a building can safely accommodate is defined as occupant load, determined during plans review.
• Gross area refers to total square footage; net area considers space occupied by furniture and non-useable areas.

Path Configurations

• Dead-end corridors exist without egress for more than 20 feet in length.
• Common paths of travel are the routes all occupants must take before diverging to separate exits.