1. Floor or Wall Assembly — Min 5 in. (127 mm) thick reinforced normal weight (140-150 pcf or 2240-2400 kg/m³) concrete. Wall may also be constructed of any UL Classified Concrete Blocks*. Max diam of opening is 14 in. (356 mm).

See Concrete Blocks (CAZT) category in the Fire Resistance Directory for names of manufacturers.

2. Steel Duct — Nom 10 in. (254 mm) diam (or smaller) No. 28 gauge (or heavier) steel duct. One duct to be installed either concentrically or eccentricity within the firestop system. The annular space between steel duct and periphery of opening shall be min 3/4 in. (19 mm) to max 3-1/4 in. (83 mm). Steel duct to be rigidly supported on both sides of floor or wall assembly.

3. Firestop System — The firestop system shall consist of the following:

A. Packing Material — Min 2 in. (51 mm) thickness of min 4 pcf (64 kg/m³) mineral wool batt insulation firmly packed into opening as a permanent form. Packing material to be recessed from top surface of floor and from both surfaces of wall to accommodate the required thickness of fill material.

B. Fill, Void or Cavity Material* — Sealant — Min 3/4 in. thickness of fill material applied within the annulus, flush with top surface of floor and both surfaces of wall. Additional fill material to be installed such that a min 1/4 in. crown is formed around the steel duct on top surface of floor or on both surfaces of wall.

RECTORSEAL — FlameSafe FS1900, FS1901, FS1905, FS1929, Metacaulk 1000, Metacaulk 350i, Biostop 350i or Biostop 500+