|BUILDING ELEMENT||TYPE I||TYPE II||TYPE III||TYPE IV||TYPE V|
|Primary structural framef (see Section 202)||3a||2a||1||0||1||0||HT||1||0|
| Nonbearing walls and partitions |
|See Table 602|
| Nonbearing walls and partitions |
|0||0||0||0||0||0|| See |
| Floor construction and associated secondary members |
(see Section 202)
| Roof construction and associated secondary members |
(see Section 202)
|For SI: 1 foot = 304.8 mm.|
|a. 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.|
|b. 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.|
|c. In all occupancies, heavy timber shall be allowed where a 1-hour or less fire-resistance rating is required.|
|d. Not less than the fire-resistance rating required by other sections of this code.|
|e. Not less than the fire-resistance rating based on fire separation distance (see Table 602).|
|f. Not less than the fire-resistance rating as referenced in Section 704.10.|
|g. 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 Table 506.2 or an allowable height increase in accordance with Tables 504.3 or 504.4. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.|
| FIRE SEPARATION DISTANCE = |
|TYPE OF CONSTRUCTION||OCCUPANCY GROUP He|| OCCUPANCY |
GROUP F-1, M, S-1f
| OCCUPANCY |
GROUP A, B, E, F-2, I, R, S-2, Uh
|X < 5b||All||3||2||1|
|5 ≤ X < 10||IA||3||2||1|
|10 ≤ X < 30||IA, IB||2||1||1c|
|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.
- 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 415.6.
- For special requirements for Group S aircraft hangars, see Section 412.4.1.
- Where Table 705.8 permits nonbearing exterior walls with unlimited area of unprotected openings, the required fire-resistance rating for the exterior walls is 0 hours.
- For a building containing only a Group U occupancy private garage or carport, the exterior wall shall not be required to have a fire-resistance rating where the fire separation distance is 5 feet (1523 mm) or greater.
TABLE 602.4 WOOD MEMBER SIZE EQUIVALENCIES
| MINIMUM NOMINAL SOLID |
| MINIMUM GLUED-LAMINATED |
| MINIMUM STRUCTURAL COMPOSITE LUMBER |
|Width, inch||Depth, inch||Width, inch||Depth, inch||Width, inch||Depth, inch|
- Sawn or glued-laminated planks, splined or tongue-and-groove, of not less than 3 inches (76 mm) nominal in thickness covered with 1-inch (25 mm) nominal dimension tongue-and-groove flooring, laid crosswise or diagonally, 15/32-inch (12 mm) wood structural panel or 1/2-inch (12.7 mm) particleboard.
- Planks not less than 4 inches (102 mm) nominal in width set on edge close together and well spiked and covered with 1-inch (25 mm) nominal dimension flooring or 15/32-inch (12 mm) wood structural panel or 1/2-inch (12.7 mm) particleboard.
Cross-laminated timber roofs shall be not less than 3 inches (76 mm) nominal in thickness and shall be continuous from support to support and mechanically fastened to one another.
1. 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 fire-resistance-rated construction is not required.
1.3. Roof construction, including girders, trusses, framing and decking.
Exception: In buildings of Type IA construction exceeding two stories above grade plane, fire-retardant-treated wood is not permitted in roof construction where the vertical distance from the upper floor to the roof is less than 20 feet (6096 mm).
2. Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.
1. 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.
2. 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.
3. Foam plastics in accordance with Chapter 26.
4. Roof coverings that have an A, B or C classification.
5. Interior floor finish and floor covering materials installed in accordance with Section 804.
6. Millwork such as doors, door frames, window sashes and frames.
7. Interior wall and ceiling finishes installed in accordance with Sections 801 and 803.
8. Trim installed in accordance with Section 806.
9. Where not installed greater than 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.
10. Finish flooring installed in accordance with Section 805.
11. 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.
12. Stages and platforms constructed in accordance with Sections 410.3 and 410.4, respectively.
13. Combustible exterior wall coverings, balconies and similar projections and bay or oriel windows in accordance with Chapter 14.
14. Blocking such as for handrails, millwork, cabinets and window and door frames.
15. Light-transmitting plastics as permitted by Chapter 26.
16. Mastics and caulking materials applied to provide flexible seals between components of exterior wall construction.
17. Exterior plastic veneer installed in accordance with Section 2605.2.
18. Nailing or furring strips as permitted by Section 803.13.
19. Heavy timber as permitted by Note c to Table 601 and Sections 602.4.7 and 1406.3.
20. Aggregates, component materials and admixtures as permitted by Section 703.2.2.
21. 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 1705.14 and 1705.15, respectively.
22. Materials used to protect penetrations in fire-resistance-rated assemblies in accordance with Section 714.
23. Materials used to protect joints in fire-resistance-rated assemblies in accordance with Section 715.
24. Materials allowed in the concealed spaces of buildings of Types I and II construction in accordance with Section 718.5.
25. Materials exposed within plenums complying with Section 602 of the International Mechanical Code.
26. Wall construction of freezers and coolers of less than 1,000 square feet (92.9 m2), in size, lined on both sides with noncombustible materials and the building is protected throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
27. Wood nailers for parapet flashing and roof cants.