The Ontario Building Code | Sound Transmission Class
5.9.1.1. Sound Transmission Class
(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 the 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".
In Plain Language
Sound transmission class ratings, used to measure how well an assembly blocks airborne noise, must be determined in accordance with ASTM E413, the referenced standard for rating sound insulation.
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.