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New York City · Through Local Law 2026/135 (enacted August 31, 2026)

N.Y.C. Admin. Code § BC 603: Section BC 603: Combustible Material in Types I and II Construction

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Where this section sits in the code
  1. New York City Administrative Code
  2. Title 28
  3. Chapter 7: New York City Building Code

603.1 Allowable materials.

Combustible materials shall be permitted in buildings of Type I or II construction in the following applications and in accordance with Sections 603.1.1 through 603.1.3.

1. Fire-retardant-treated wood, complying with Section 2303.2, shall be permitted in:

1.1. Nonbearing interior partitions where the required fire-resistance rating is 1 hour or less.

Exception: Public corridors and exits shall be constructed of noncombustible materials.

1.2. Roof construction as permitted in Table 601, Note b.

2. Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.

Exceptions:

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 or B classification as defined in Section 1505.

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 (1828.8 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 602.4.3.

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 New York City Mechanical Code.

26. Bleachers, grandstands, and folding and telescopic seating within an assembly space in accordance with Section 1029.1.1 of this code.

603.1.1 Ducts.

The use of nonmetallic ducts shall be permitted where installed in accordance with the limitations of the New York City Mechanical Code.

603.1.2 Piping.

The use of combustible piping materials shall be permitted where installed in accordance with the limitations of the New York City Mechanical Code and the New York City Plumbing Code.

603.1.3 Electrical.

The use of electrical wiring methods with combustible insulation, tubing, raceways and related components shall be permitted where installed in accordance with the limitations of the New York City Electrical Code.

Collected 2026-09-06T02:48:57Z. Source file · JSON

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