The Ontario Building Code | Determination of Sound Transmission Class Ratings
9.11.1.1. Determination of Sound Transmission Class Ratings
(1) Sound transmission class ratings shall be determined in accordance with ASTM E413, "Classification for Rating Sound insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation", using results from measurements in accordance with,
(a) ASTM E90, "Laboratory Measurement of Airborne Sound Transmission Loss of building Partitions and Elements", or
(b) ASTM E336, "Measurement of Airborne Sound Attenuation Between Rooms in Buildings".
9.11.2. Required Sound Control Locations (Airborne Sound)
In Plain Language
Sound transmission class (STC) ratings for walls, floors, and ceilings between units must be determined per the method set out in this article, giving a standardized measure of how well an assembly blocks sound.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.