FIRE-RESISTANCE RATING REQUIREMENTS FOR BUILDING ELEMENTS (hours)
|BUILDING ELEMENT||TYPE I||TYPE II||TYPE III||TYPE IV||TYPE V|
Primary structural frameg(see Section 202)
|Nonbearing walls and partitions||See Table 602|
|Nonbearing walls and partitions||0||0||0||0||0||0||See Section 602.4.6||0||0|
Floor construction and secondarymembers (see Section 202)
Roof construction and secondarymembers (see Section 202)
|11/2b||1b, c||1b, c||0c||1b, c||0||HT||1b, c||0|
For SI: 1 foot = 304.8 mm.
- Roof supports: Fire-resistance ratings of primary structural frame and bearing walls are permitted to be reduced by 1 hour where supporting a roof only.
- Except in Group F-1, H, M and S-1 occupancies, fire protection of structural members shall not be required, including protection of roof framing and decking where every part of the roof construction is 20 feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
- In all occupancies, heavy timber shall be allowed where a 1-hour or less fire-resistance rating is required.
- An approved automatic sprinkler system in accordance with Section 903.3.1.1 shall be allowed to be substituted for 1-hour fire-resistance-rated construction, provided such system is not otherwise required by other provisions of the code or used for an allowable area increase in accordance with Section 506.3 or an allowable height increase in accordance with Section 504.2. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.
- Not less than the fire-resistance rating required by other sections of this code.
- Not less than the fire-resistance rating based on fire separation distance (see Table 602).
- Not less than the fire-resistance rating as referenced in Section 704.10
FIRE-RESISTANCE RATING REQUIREMENTS FOR EXTERIOR WALLS BASED ON FIRE SEPARATION DISTANCEa, e, h
|FIRE SEPARATION DISTANCE = X|
|TYPE OF CONSTRUCTION||OCCUPANCY |
GROUP F-1, M, S-1g
GROUP A, B, E, F-2, I, R, S-2g, Ub
|X < 5c||All||3||2||1|
|5 ≤ X < 10||IA|
|10 ≤ X < 30||IA, IB|
|X ≥ 30||All||0||0||0|
For SI: 1 foot = 304.8 mm.
- Load-bearing exterior walls shall also comply with the fire-resistance rating requirements of Table 601.
- For special requirements for Group U occupancies, see Section 406.1.2.
- See Section 706.1.1 for party walls.
- Open parking garages complying with Section 406 shall not be required to have a fire-resistance rating.
- The fire-resistance rating of an exterior wall is determined based upon the fire separation distance of the exterior wall and the story in which the wall is located.
- For special requirements for Group H occupancies, see Section 415.3.
- For special requirements for Group S aircraft hangars, see Section 412.4.1.
- Buildings and structures with an occupancy in Group H-3 used for the display, sale or storage of fireworks, 1.4G, shall be located in accordance with Section 415 and the fire code.
Type IV construction (Heavy Timber, HT) is that type of construction in which the exterior walls are of noncombustible materials and the interior building elements are of solid or laminated wood without concealed spaces. The details of Type IV construction shall comply with the provisions of this section. Fire-retardant-treated wood framing complying with Section 2303.2 shall be permitted within exterior wall assemblies with a 2-hour rating or less. Minimum solid sawn nominal dimensions are required for structures built using Type IV construction (HT). For glued-laminated members the equivalent net finished width and depths corresponding to the minimum nominal width and depths of solid sawn lumber are required as specified in Table 602.4.
WOOD MEMBER SIZE
|MINIMUM NOMINAL SOLID SAWN SIZE||MINIMUM GLUED-LAMINATED NET SIZE|
|Width, inch||Depth, inch||Width, inch||Depth, inch|
For SI: 1 inch = 25.4 mm.
- Fire-retardant-treated wood shall be permitted in:
- 1.1. Nonbearing partitions where the required fire-resistance rating is 2 hours or less.
- 1.2. Nonbearing exterior walls where no fire rating is required.
- 1.3. Roof construction, including girders, trusses, framing and decking.
- Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.
- Insulation placed between two layers of noncombustible materials without an intervening airspace shall be allowed to have a flame spread index of not more than 100.
- Insulation installed between a finished floor and solid decking without intervening airspace shall be allowed to have a flame spread index of not more than 200.
- Foam plastics in accordance with Chapter 26.
- Roof coverings that have an A, B or C classification.
- Interior floor finish and floor covering materials installed in accordance with Section 804.
- Millwork such as doors, door frames, window sashes and frames.
- Interior wall and ceiling finishes installed in accordance with Sections 801 and 803.
- Trim installed in accordance with Section 806.
- Where not installed over 15 feet (4572 mm) above grade, show windows, nailing or furring strips and wooden bulkheads below show windows, including their frames, aprons and show cases.
- Finish flooring installed in accordance with Section 805.
- Partitions dividing portions of stores, offices or similar places occupied by one tenant only and that do not establish a corridor serving an occupant load of 30 or more shall be permitted to be constructed of fire-retardant-treated wood, 1-hour fire-resistance-rated construction or of wood panels or similar light construction up to 6 feet (1829 mm) in height.
- Stages and platforms constructed in accordance with Sections 410.3 and 410.4, respectively.
- Combustible exterior wall coverings, balconies and similar projections and bay or oriel windows in accordance with Chapter 14.
- Blocking such as for handrails, millwork, cabinets and window and door frames.
- Light-transmitting plastics as permitted by Chapter 26.
- Mastics and caulking materials applied to provide flexible seals between components of exterior wall construction.
- Exterior plastic veneer installed in accordance with Section 2605.2.
- Nailing or furring strips as permitted by Section 803.4.
- Heavy timber as permitted by Note c to Table 601 and Sections 602.4.7 and 1406.3.
- Aggregates, component materials and admixtures as permitted by Section 703.2.2.
- Sprayed fire-resistant materials and intumescent and mastic fire-resistant coatings, determined on the basis of fire-resistance tests in accordance with Section 703.2 and installed in accordance with Sections 1704.12 and 1704.13, respectively.
- Materials used to protect penetrations in fire-resistance-rated assemblies in accordance with Section 713.
- Materials used to protect joints in fire-resistance-rated assemblies in accordance with Section 714.
- Materials allowed in the concealed spaces of buildings of Types I and II construction in accordance with Section 717.5.
- Materials exposed within plenums complying with Section 602 of the mechanical code.