2024 Ontario Building Code Sound Transmission Standards: OBC 9.11.1 and Acoustic Compliance
Sarah's Expert Insight
OBC Compliance Specialist
"The transition toward prioritizing Apparent Sound Transmission Class (ASTC) ratings is a significant shift for developers in London and Oakville, as it forces us to look at the 'flanking' paths where sound leaks around walls. At empcontracting.ca Inc. your construction contractor in London, Ontario, we emphasize the use of SB-3 compliant assemblies and high-grade gaskets near elevator shafts to ensure our builds exceed the STC 55 requirement, providing the luxury-level quiet that Muskoka and Oakville clients expect."
Introduction to Sound Transmission in the 2024 OBC
Ensuring acoustic privacy between dwelling units is a critical component of modern residential construction. According to the 2024 Building Code Compendium, Section 9.11 focuses on protection from airborne noise to improve the quality of life for occupants in multi-unit buildings. At empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure every project meets these rigorous laboratory and field-tested standards.
9.11.1.1 Required Protection and Ratings
To provide adequate separation, a dwelling unit or a hotel suite must be separated from other spaces by assemblies that meet specific ratings:
- ASTC 47: An Apparent Sound Transmission Class rating of at least 47, which accounts for both the separating assembly and flanking constructions.
- STC 50: A Sound Transmission Class rating of at least 50 when adjoining constructions conform to Article 9.11.1.4.
- STC 55: High-traffic noise areas, such as construction separating a unit from an elevator shaft or refuse chute, require a higher rating of at least 55.
9.11.1.2 Determination of Sound Transmission Ratings
Ratings are determined via standardized testing methods to ensure accuracy and consistency across Ontario construction projects:
- STC Ratings: Measured according to ASTM E90 and classified under ASTM E413.
- ASTC Ratings: Determined through field measurements (ASTM E336) or calculated based on the specific assembly and flanking paths as per Section 5.8.
9.11.1.3 Compliance with Required Ratings
Contractors can demonstrate compliance through two primary paths: direct measurement by an acoustic specialist or by following the prescriptive construction assemblies outlined in MMAH Supplementary Standard SB-3, "Fire and Sound Resistance Tables." Using pre-approved assemblies ensures that projects in London and the surrounding areas remain compliant without the need for exhaustive field testing in every instance.
Kitchen Cabinetry and Heating Element Clearances
In addition to soundproofing, the code specifies safety clearances for kitchen installations. Cabinetry located at least 450 mm above heating elements or burners generally does not require additional protection, and countertop splash boards that extend above the level of burners are also exempt from specific protection requirements under Sentence 9.10.22.2.
Disclaimer: This content is generated from the Ontario Building Code for educational purposes. Always consult with a licensed professional engineer or your local building department before starting any construction project in London, Ontario.