Section 9.11 — Sound Transmission (See Note A-9.11.)

(1) Except as provided in Sentence (3), a dwelling unit and a suite in hotels shall be separated from every other space in a building in which noise may be generated by (a) a separating assembly and adjoining constructions, which, together, provide an apparent sound transmission class (ASTC) rating of not less than 47, or (b) a separating assembly that provides a sound transmission class (STC) rating of at least 50 and adjoining constructions that conforms to Article 9.11.1.4. (See Note A-9.11.1.4.) (2) Reserved. (3) Construction separating a dwelling unit or suite in a hotel from an elevator shaft or refuse chute shall have an STC rating of not less than 55.

(1) The STC ratings shall be determined in accordance with ASTM E413, “Classification for Rating Sound Insulation,” using the results from measurements carried out in accordance with ASTM E90, “Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements.” (2) The ASTC ratings shall be (a) determined in accordance with ASTM E413, “Classification for Rating Sound Insulation,” using the results from measurements carried out in accordance with ASTM E336, “Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings,” or (b) calculated in accordance with Article 5.8.1.4. or Article 5.8.1.5.

(1) Compliance with the required STC ratings shall be demonstrated through (a) measurements carried out in accordance with Sentence 9.11.1.2.(1), or (b) the construction of separating assemblies conforming to Table 1 or 2 of MMAH Supplementary Standard SB-3, “Fire and Sound Resistance Tables,” as applicable. (2) Compliance with the required ASTC ratings shall be demonstrated through (a) measurements or calculations carried out in accordance with Sentence 9.11.1.2.(2), or (b) the construction of separating assemblies conforming to Table 1 or 2 of MMAH Supplementary Standard SB-3, “Fire and Sound Resistance Tables,” as applicable, that have an STC rating of not less than 50 in conjunction with flanking assemblies constructed in accordance with Article 9.11.1.4. (See Note A-9.11.1.3.(2)(b))

(1) This Article applies where the required protection is provided in accordance with Clause 9.11.1.1.(1)(b) and compliance is demonstrated in accordance with Clause 9.11.1.3.(2)(b). (2) Flanking wall assemblies connected to a separating floor or ceiling assembly shall be constructed with (a) concrete or concrete block having a mass per area greater than 200 kg/m2, or (b) gypsum board finish that (i) is supported on wood or steel framing, and (ii) ends or is interrupted where it meets the structure of the separating floor or ceiling assembly. (3) Flanking wall and ceiling assemblies connected to a separating wall assembly shall be constructed with (a) concrete or concrete block having a mass per area greater than 300 kg/m 2, or (b) gypsum board finish that (i) is supported on wood or steel framing, and (ii) ends or is interrupted where it meets the structure of the separating wall assembly or, for double-stud walls, where it meets the space between the two lines of studs. (4) Flanking floor assemblies connected to a separating wall assembly shall be (a) constructed (i) with concrete having a mass per area greater than 300 kg/m 2, or (ii) in accordance with Section 9.16., or (b) supported on joists or trusses that are not continuous across the junction and are covered with floor treatments in accordance with Table 9.11.1.4. for the applicable wall construction. Table 9.11.1.4. Floor Treatments for Flanking Wood-Framed Floor Assemblies in Horizontally Adjoining Spaces Forming Part of Sentence 9.11.1.4.(4) Type of Separating Wall Assembly with STC ≥ 50 from Minimum Requirements for Floor Treatments Applied over Subfloor of Wood-Framed MMAH Supplementary Standard SB-3, “Fire Flanking Floor Assemblies on Both Sides of Floor/Wall Junction and Sound Resistance Tables” • wood strip flooring not less than 16 mm thick aligned parallel to separating wall, or • one layer OSB or plywood not less than 15.5 mm thick plus finished flooring, or W5, W6, W10, W12 (staggered studs) • one additional material layer plus finished flooring having a combined mass per area not less than 8 kg/m²(1) • one layer of OSB or plywood not less than 12.5 mm thick plus hardwood strip flooring not less than 19 mm thick aligned parallel to separating wall, or W4, W11 (staggered studs) • one additional material layer plus finished flooring having a combined mass per area not less than 16 kg/m²(1) • concrete or gypsum concrete topping not less than 19 mm thick bonded to the subfloor plus finished flooring, or W8, W9 (staggered studs) • one additional material layer plus finished flooring having a combined mass per area not less than 32 kg/m²(1) Table 9.11.1.4. (Cont’d) Floor Treatments for Flanking Wood-Framed Floor Assemblies in Horizontally Adjoining Spaces Forming Part of Sentence 9.11.1.4.(4) Type of Separating Wall Assembly with STC ≥ 50 from Minimum Requirements for Floor Treatments Applied over Subfloor of Wood-Framed MMAH Supplementary Standard SB-3, “Fire Flanking Floor Assemblies on Both Sides of Floor/Wall Junction and Sound Resistance Tables” • where a continuous subfloor or other rigid materials at the floor/wall junction provide structural connection between the two rows of studs in the separating wall: • hardwood strip flooring not less than 16 mm thick aligned parallel to separating wall, or • one layer OSB or plywood not less than 15.5 mm thick plus finished flooring, or W13, W14, W15 (double stud walls) • one additional material layer plus finished flooring having a combined mass per area not less than 8 kg/m²(1) • any finished flooring where the subfloor and other rigid materials are not connected at the floor/wall junction and where there are no structural connections between the two rows of studs in the separating wall B1 to B10 • any finished flooring Notes to Table 9.11.1.4.: (1) See Note A-Table 9.11.1.4.