§ 18-28-602.2.1 — Materials exposed within plenums

18-28-602.2.1 Materials exposed within plenums.

Materials exposed within plenums shall be noncombustible or shall be listed and labeled as having a flame spread index of not more than 25 and a smoke-developed index of not more than 50 when tested in accordance with ASTM E 84 or UL 723. No floor drains or sanitary waste and vent piping, storm drain piping or condensate drain piping may be exposed within a supply plenum. No material which has the potential of contaminating the air stream may be located in a supply plenum. Exceptions: 1. Rigid and flexible ducts and connectors shall conform to Section 18-28-603. 2. Duct coverings, linings, tape and connectors shall conform to Sections 18-28-603 and 18-28-604. 3. This section shall not apply to materials exposed within plenums in Group R-5 occupancies. 4. This section shall not apply to smoke detectors. (Amend Coun. J. 9-14-21, p. 35949, Art. VI, § 2)