Penetratio Firestop Systems: Key Ratings, Applications, and Standards

Penetration Firestop Systems

Penetration firestop systems are those that penetrate one side, as is the case with a membrane penetration, or both sides, in the case of a through penetration. These systems are used to restore the hourly rating of a tested vertical or horizontal assembly when penetrated by elements like pipes or cables. The systems are essential in maintaining the integrity of fire-rated barriers.

Key Elements of Firestop Systems

• F Rating: Evaluates the time the system prevents flame passage (in hours).
• T Rating: Measures the time the system limits temperature rise on the unexposed side.
• L Rating: Determines air leakage rates at specific pressures and temperatures.
• W Rating: Assesses water resistance and performance after water exposure.

Explanation

Firestop systems are critical for ensuring the safety of fire-rated assemblies like walls, floors, and ceilings. They restore the fire resistance rating after these assemblies are penetrated. The ratings (F, T, L, W) are determined based on standardized tests like ASTM E814 and UL 1479, which assess performance against flame, temperature rise, air leakage, and water exposure.

Determining Fire Barrier Location and Rating

The process of determining fire barrier locations and their hourly ratings is essential for ensuring building safety and compliance with fire protection standards. Here's a detailed breakdown:

1. New Construction Projects

• Architectural Drawings: Fire-resistance-rated barriers are typically marked in architectural blueprints. These include walls, floors, or ceilings with specific fire ratings.
• Fire Protection Engineer Input: If a fire protection engineer is involved, separate fire barrier drawings are often provided, showing precise locations and their hourly fire resistance ratings.

2. Existing Construction

• Limited Guidance: In older buildings, fire-rated barriers may not be clearly indicated in the original drawings or may not exist at all.
• Building Study: A thorough examination of the structure and the local building codes is required to locate fire-rated assemblies.
• Common Fire-Resistant Areas:
  • Floors: Typically rated for 1 or 2 hours to provide fire separation between stories.
  • Shafts and Stairs: Enclosed vertical spaces like stairwells and elevator shafts are usually rated for 1 or 2 hours, depending on the building’s height.
  • Special Rooms:
    • Boiler Rooms, Incinerator Rooms, and Large Storage Areas: Rooms larger than 100 ft² (9.3 m²) often have 2-hour fire-resistance ratings.
    • Paint Shops and Maintenance Areas: Generally require 2-hour-rated construction.
  • Tenant and Dwelling Separations: Spaces between different tenants or units (like apartments) are often rated for 1 hour.
  • Corridors: Hallways leading to exits typically require 1-hour ratings, though this may vary if automatic sprinklers are installed.

3. Special Cases

• Smaller Storage Rooms (<100 ft² or 9.3 m²): These usually require only a 1-hour fire resistance rating.
• Trash and Linen Chute Access Rooms: Commonly separated with 1-hour-rated barriers.
• Laboratories: Often classified for 1-hour fire separation due to the nature of activities conducted there

  Multiple Choice Questions

  1. What does the F rating measure in firestop systems?

  1. The system's resistance to water.
  2. The time to limit temperature rise.
  3. The time to withstand flame passage.
  4. The air leakage rate.

  Correct Answer: C

  2. Which test generates both F and T ratings?

  1. ASTM E814
  2. UL 1479
  3. NFPA 101
  4. ISO 9001

  Correct Answer: A

  3. Which rating is optional in UL 1479 but not included in ASTM E814?

  1. F Rating
  2. T Rating
  3. L Rating
  4. W Rating

  Correct Answer: C

  4. What is the main purpose of penetration firestop systems?

  1. To protect against water damage.
  2. To restore fire-rated assembly integrity after penetration.
  3. To provide ventilation in enclosed spaces.
  4. To reduce noise transmission between rooms.

  Correct Answer: B