I. General
the Installation of Sprinkler Systems, on all floors, ENT shall be permitted to be used within walls, floors, and ceilings, exposed or concealed, in buildings exceeding three floors abovegrade.
FPN: A finish rating is established for assemblies containing combustible (wood) supports. The finish rating is defined as the time at which the wood stud or wood joist reaches an average temperature rise of
121°C (250°F) or an individual temperature of 163°C
(325°F) as measured on the plane of the wood nearest
362.1 Scope. This article covers the use, installation, and construction specifications for electrical nonmetallic tubing (ENT) and associated fittings.
362.2 Definition.
Electrical Nonmetallic Tubing (ENT). A nonmetallic, pli- able, corrugated raceway of circular cross section with integral or associated couplings, connectors, and fittings for the installation of electrical conductors. ENT is composed of a material that is resistant to moisture and chemical atmospheres and is flame retardant.
A pliable raceway is a raceway that can be bent by hand with a reasonable force but without other assistance.
362.6 Listing Requirements. ENT and associated fittings shall be listed.
II. Installation
362.10 Uses Permitted. For the purpose of this article, the first floor of a building shall be that floor that has 50 percent or more of the exterior wall surface area level with or above finished grade. One additional level that is the first level and not designed for human habitation and used only for vehicle parking, storage, or similar use shall be permitted. The use of ENT and fittings shall be permitted in the following:
(1) In any building not exceeding three floors above grade as follows:
a. For exposed work, where not prohibited by 62.12 b. Concealed within walls, floors, and ceilings
(2) In any building exceeding three floors above grade, ENT shall be concealed within walls, floors, and ceil- ings where the walls, floors, and ceilings provide a thermal barrier of material that has at least a 15- minute finish rating as identified in listings of fire- rated assemblies. The 15-minute-finish-rated thermal barrier shall be permitted to be used for combustible or noncombustible walls, floors, and ceilings.
Exception to (2): Where a fire sprinkler system(s) is in- stalled in accordance with NFPA 13-2007, Standard for
the fire. A finish rating is not intended to represent a rating for a membrane ceiling.
(3) In locations subject to severe corrosive influences as covered in 300.6 and where subject to chemicals for which the materials are specifically approved.
(4) In concealed, dry, and damp locations not prohibited by 362.12.
(5) Above suspended ceilings where the suspended ceilings provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire-rated assemblies, except as permitted in 362.10(l)(a).
Exception to (5): ENT shall be permitted to be used above suspended ceilings in buildings exceeding three floors above grade where the building is protected throughout by a fire sprinkler system installed in accordance with NFPA 13-2007, Standard for the Installation of Sprinkler Systems.
(6) Encased in poured concrete, or embedded in a concrete slab on grade