Flame-spread ratings and smoke developed classification limits for combustible insulation and coverings used on piping located within:

• concealed spaces in walls,
• floor slabs, or
• noncombustible enclosures.

This applies to buildings described in Sentence 1.3.3.2.(1) of Division A.

This also applies to:

• the fire safety characteristics of heating, ventilating and air-conditioning systems, as stated in Article 6.2.1.2., and
• buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], with respect to:
  • mechanical ventilation systems other than self-contained systems serving single dwelling units, as stated in Sentence 9.32.1.1.(2),
  • the ventilation of storage garages for more than 5 motor vehicles in residential occupancies, as stated in Sentence 9.32.1.1.(3),
  • mechanical ventilation systems used for the ventilation of rooms and spaces in dwelling units during the non-heating season, where natural ventilation is not provided in accordance with Article 9.32.2.2., as stated in Clause 9.32.2.1.(1)(b),
  • heating and air-conditioning systems other than those serving individual dwelling units, as stated in Sentence 9.33.1.1.(2), and
  • air duct distribution systems in which the rated heat input exceeds 120 kW, as stated in Sentence 9.33.6.1.(2).

To exempt combustible insulation and coverings used on pipes in certain locations from the requirements of Sentences 3.6.5.5.(2) to (4), which would otherwise impose certain flame-spread ratings and smoke-developed classifications, on the basis that the pipes are concealed in a manner that they would not easily be exposed to fire burning outside the concealed space.