Chapter 4 General Requirements

The provisions of this chapter apply to high challenge (HC) fire walls, fire walls, and fire barrier walls unless modified by provisions of Chapters 5, 6, or 7, respectively, and shall hereafter in this chapter be referred to as walls.

4.2* Design Loads

All walls and their supports shall be designed for loads in accordance with ASCE/SEI 7, Minimum Design Loads for Buildings and Other Structures, and to withstand a minimum uniform load of 5 lbf/ft 2 (0.24 kPa) from either direction applied perpendicular to the face of the wall.

4.3 Fire Resistance Ratings

4.3.1

The fire resistance rating of assemblies shall be determined in accordance, ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and Materials, or ANSI/UL 263, Standard for Fire Tests of Building Construction and Materials, or other approved test methods or analytical methods in accordance with 4.3.2.

4.3.2 Analytical Methods

4.3.2.1 General

Analytical methods utilized to determine the fire resistance rating of building assemblies shall comply with 4.3.2.2 or 4.3.2.3.

4.3.2.2* Calculations

4.3.2.2.1

Where calculations are used to establish the fire resistance rating of structural elements or assemblies, they shall be permitted to be performed in accordance with ASCE/SFPE 29.

4.3.2.2.2

Where calculations are used to establish the fire resistance rating of concrete or masonry elements or assemblies, the provisions of ACI 216.1/TMS 0216.1, Code Requirements for Determining Fire Resistance of Concrete and Masonry Construction Assemblies, shall be permitted to be used.

4.3.2.3 Methods

4.3.2.3.1

Except for the method specified in 4.3.2.2, analytical methods used to calculate the fire resistance rating of building assemblies or structural elements shall be approved.

4.3.2.3.2

Where an approved analytical method is utilized to establish the fire resistance rating of a structural element or building assembly, the calculations shall be based on the fire exposure and acceptance criteria specified in ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and Materials, or UL 263, Standard for Fire Tests of Building Construction and Materials.

4.4 Ducts and Air-Transfer Openings

4.4.1 General

The provisions of Section 4.4 shall govern the materials and methods of construction used to protect ducts and air-transfer openings in fire walls, fire resistance-rated horizontal assemblies, and fire barrier walls.

4.4.2* Fire Damper Requirements

Fire dampers shall be installed to protect ducts and air-transfer openings that penetrate fire barriers and fire walls as required by other sections of the applicable building code.

4.4.2.1

Fire dampers shall be designed and tested in accordance with the requirements of UL 555, Standard for Safety of Fire Dampers, and shall have the minimum fire protection rating specified in Table 4.4.2.1 for the rating of the assembly penetrated.

Fire Resistance Rating of Wall Assembly Minimum Damper Rating (hr) 3-hr or greater fire resistance-rated assemblies Less than 3-hr fire resistance-rated assemblies

4.4.2.2

In systems where fans continue to operate in the emergency mode, dynamic fire dampers shall be required.

4.4.2.3

  1. Ducts and air-transfer openings penetrating walls or partitions having a fire resistance rating of 2 or more hours
  2. Ducts and air-transfer openings penetrating shaft walls having a fire resistance rating of 1 or more hours
  3. Air-transfer openings that occur in walls or partitions that are required to have a fire-resistive rating of 30 minutes or more

4.4.2.4

  1. In a duct system serving only one floor and used only for exhaust of air to the outside and not penetrating a wall having a required fire resistance rating of 2 hours or more or passing entirely through the system and contained within its own dedicated shaft
  2. Where branch ducts connect to enclosed exhaust risers in which the airflow is upward, and steel subducts at least 22 in. (560 mm) in length are carried up inside the riser at each inlet

4.4.3 Installation

4.4.3.1

Air-conditioning, heating, and ventilating ductwork and related equipment, including fire dampers, smoke dampers, combination fire and smoke dampers, and ceiling radiation dampers, shall be installed in accordance with NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems, or NFPA 90B, Standard for the Installation of Warm Air Heating and Air-Conditioning Systems, where applicable.

4.4.3.2

The equipment specified in 4.4.3.1 shall be installed in accordance with the requirements of Section 4.4, the manufacturer's installation instructions, its listing, and the applicable mechanical code as specified in Chapter 50 of NFPA 5000, Building Construction and Safety Code.

4.4.4 Access and Identification

4.4.4.1 Access

  1. The means of access shall be large enough to allow inspection and maintenance of the damper and its operating parts.
  2. The access shall not affect the integrity of fire resistance-rated assemblies.
  3. The access openings shall not reduce the fire resistance rating of the assembly.
  4. Access doors in ducts shall be tight-fitting and suitable for the required duct construction.
  5. Access and maintenance shall comply with the requirements of the mechanical code.

4.4.4.2 Identification

  1. A label having letters not less than 1 /2 in. (13 mm) in height reading as follows in (a), (b), or (c):
    1. FIRE/SMOKE DAMPER
    2. SMOKE DAMPER
    3. FIRE DAMPER

    4.4.5* Fire Damper Actuation Device

    The operating temperature of the heat-actuating device shall be approximately 50°F (27.8°C) above the normal temperature within the duct system, but not less than 160°F (71°C); or it shall be not more than 286°F (141°C) where located in a required smoke control system; or, where a combination fire and smoke damper is installed, it shall not exceed 350°F (177°C) where located in a smoke control system.

    4.5* Double Wall Assemblies

    Where either wall of a double wall is laterally supported by a building frame with a fire resistance rating less than that required for the wall, double wall assemblies shall be considered to have a combined assembly fire resistance rating as specified in Table 4.5.

    Fire Resistance Rating of
    Each Wall (hr)     Equivalent to
    Single Wall (hr)

    4.6* Impact Damage

    4.6.1

    Where the wall is subject to impact damage from moving vehicles or the handling of merchandise or other activity, protection against impact damage shall be provided for an appropriate height but not less than 60 in. (1525 mm) from the finished floor.

    4.6.2

    Where the fire-protective covering of a structural element required to have a fire resistance rating by Section 5.4 or Section 6.4 is subject to impact damage from moving vehicles, the handling of merchandise, or other activity, protection against impact damage shall be provided for an appropriate height but not less than 60 in. (1525 mm) from the finished floor.

    4.7* Joints

    The provisions of Section 4.7 shall govern the materials and methods of construction used to protect joints within or between walls in accordance with 4.7.1.

    4.7.1 Joint System Required

    4.7.1.1

    Joints made within or between fire resistance-rated assemblies shall be protected with a joint system that is designed and tested to prevent the spread of fire for a time period equal to that of the assembly in which the joint is located.

    4.7.1.2

    The materials, systems, or devices specified in 4.7.1.1 shall be tested as part of the assembly in accordance with the requirements of ASTM E 1966, Standard Test Method for Fire-Resistive Joint Systems, or ANSI/UL 2079, Standard for Tests for Fire Resistance of Building Joint Systems.

    4.7.1.2.1

    Testing of the joint system shall be representative of the actual installation.

    4.7.1.2.2

    All joint systems shall be tested at their maximum joint width in accordance with the requirements of ASTM E 1966, Standard Test Method for Fire-Resistive Joint Systems, or ANSI/UL 2079, Standard for Tests for Fire Resistance of Building Joint System, under a minimum positive pressure differential of 0.01 in. of water column (2.5 Pa) for a time period equal to that of the assembly.

    4.7.1.2.3

    All test specimens shall comply with the minimum height or length required by the standard.

    4.7.1.2.4

    Wall assemblies shall be subjected to a hose stream test in accordance with ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and Materials, or UL 263, Standard for Fire Tests of Building Construction and Materials.