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Wood is composed of many small cellular tubes that are predominantly filled with air. The natural composition of the material allows for wood to act as an effective acoustical insulator and provides it with the ability to dampen vibrations. These sound-dampening characteristics allow for wood construction elements to be specified where sound insulation or amplification is required, such as libraries and auditoriums. Another important acoustical property of wood is its ability to limit impact noise transmission, an issue commonly associated with harder, more dense materials and construction systems. The use of topping or a built-up floating floor system overlaid on light wood frame or mass timber structural elements is a common approach to address acoustic separation between floors of a building. Depending on the type of materials in the built-up floor system, the topping can be applied directly to the wood structural members or over top of a moisture barrier or resilient layer. The use of gypsum board, absorptive (batt/loose-fill) insulation and resilient channels are also critical components of a wood-frame wall or floor assembly that also contribute to the acoustical performance of the overall assembly. Acoustic design considers a number of factors, including building location and orientation, as well as the insulation or separation of noise-producing functions and building elements. Sound Transmission Class (STC), Apparent Sound Transmission Class (ASTC) and Impact Insulation Class (IIC) ratings are used to establish the level of acoustic performance of building products and systems. The different ratings can be determined on the basis of standardized laboratory testing or, in the case of ASTC ratings, calculated using methodologies described in the NBC. Currently, the National Building Code of Canada (NBC) only regulates the acoustical design of interior wall and floor assemblies that separate dwelling units (e.g. apartments, houses, hotel rooms) from other units or other spaces in a building. The STC rating requirements for interior wall and floor assemblies are intended to limit the transmission of airborne noise between spaces. The NBC does not mandate any requirements for the control of impact noise transmission through floor assemblies. Footsteps and other impacts can cause severe annoyance in multifamily residences. Builders concerned about quality and reducing occupant complaints will ensure that floors are designed to minimize impact transmission. Beyond conforming to the minimum requirements of the NBC in residential occupancies, designers can also establish acoustic ratings for design of non-residential projects and specify materials and systems to ensure the building performs at that level. In addition to limiting transmission of airborne noise through internal structural walls and floors, flanking transmission of sound through perimeter joints and sound transmission through non-structural partition walls should also be considered during the acoustical design. Further information and requirements related to STC, ASTC and IIC ratings are provided in Appendix A of the NBC in sections A-9.10.3.1. and A-9.11.. This includes, inter alia, Tables 9.10.3.1-A and 9.10.3.1.-B that provide generic data on the STC ratings of different types of wood stud walls and STC and IIC ratings for different types of wood floor assemblies, respectively. Tables A-9.11.1.4.-A to A-9.11.1.4.-D present generic options for the design and construction of junctions between separating and flanking assemblies. Constructing according to these options is likely to meet or exceed an ASTC rating of 47 that is mandated by the NBC. Table A-Table 9.11.1.4. presents data about generic floor treatments that can be used to improve the flanking sound insulation performance of lightweight framed floors, i.e., additional layers of material over the subfloor (e.g. concrete topping, OSB or plywood) and finished flooring or coverings (e.g., carpet, engineered wood).

In a context where wood construction is gaining momentum, acoustics remains a key challenge in ensuring occupant comfort and compliance with standards. With this in mind, AcoustiTECH, an expert in acoustic solutions, has partnered with FPInnovations, a leader in research and development in the wood sector, to conduct an in-depth comparative study in its laboratory facility. Who We Are AcoustiTECH is a broker specializing in acoustic solutions, supporting building professionals in selecting highperformance materials that meet and exceed industry standards. With 25 years of experience and unique expertise, we offer customized assemblies through a specialized brand ecosystem and reliable data. Our personalized service, backed by dedicated technical and engineering teams, ensures tailored and effective solutions that enhance the acoustic comfort of occupants. FPInnovations is a globally recognized, private, non-profit organization specializing in research and development for the forestry sector. Its mission is to support businesses and building professionals in innovating and optimizing wood-based materials. With ISO 17025-accredited laboratories and state-of-the-art facilities, FPInnovations assesses the performance of wood structures in terms of acoustics, vibrations, fire resistance, and more. Study Objective At AcoustiTECH, our goal is to continuously innovate by delivering new data and acoustic solutions tailored to the specific requirements of each project. This collaboration with FPInnovations marks a significant milestone in our acoustic analysis of wood structures, as it represents our first large-scale data collection on a GLT masstimber slab and our second mass-timber campaign overall, building on a prior study. Through this study, we obtain precise acoustic measurements for this structural system and conduct rigorous comparisons across numerous innovative market solutions. We take into account key project criteria such as acoustic performance, budget, thickness, weight, and even design, as different acoustic solutions can also influence the choice of floor coverings. Grounded in a scientific approach and conducted in controlled environments with FPInnovations, this research aims to evaluate various acoustic configurations optimized for mass timber construction. By combining technical expertise, innovation, and in-depth analysis, we provide architects, engineers, and developers with high-performance solutions that meet and exceed the industry standards.

Setting a new standard in Canada’s tallest mass timber structure, Soprema Insonomat system provided an ideal balance of sustainability, safety, and superior sound insulation.

AcoustiTECH’s innovative and effective acoustic solutions made New York’s first mass timber residential project a triumph of modern design and sound comfort. Discover how the AcoustiTECH Lead 6 and AcoustiTECH SOFIX system harmonized natural aesthetics with high acoustic performance.

Offering beautiful views and exceptional acoustic comfort, the Lakeside project benefited from AcoustiTECH’s innovative approach to residential sound insulation.

Discover how the Travino project benefited from AcoustiTECH’s Acoustiboard and Acoustivibe solutions, achieving unmatched acoustic comfort for residents while complying with seismic requirements.

With the lightweight and resilient Fermacell 2E32 and Soprema Acoustivibe systems, this project is a model of acoustic excellence and seismic compatibility. Discover how our solutions elevated resident comfort.

This Rothoblaas document explores the role of underfloor insulation in improving acoustic performance in long-span cross-laminated timber (CLT) floor systems. Intended for designers, engineers, and building professionals, the document addresses key soundproofing challenges associated with larger spans and exposed timber structures. The document explains how underfloor insulation contributes to reducing airborne and impact sound transmission, with discussion of system behaviour, material selection, and integration with CLT floor assemblies. It also highlights design and construction considerations that influence acoustic performance, including detailing, installation quality, and coordination with other building systems. Developed as a technical reference, this document supports informed design decisions for long-span CLT floors, helping project teams achieve acoustic comfort while maintaining structural and architectural objectives.

The following report contains the Transmission Loss (TL) results measured in accordance with ASTM E90-09 of 8 cross-laminated timber (CLT) wall assemblies and the TL results and normalized impact sound pressure level results measured in accordance with ASTM E492-09 of 26 CLT floor assemblies and 3 glulam floor assemblies. Reference tables containing the specimen number, sketch, short description, rating(s) as well as the page number of all the assemblies tested are found starting on page 16. The wall assemblies were built and tested between November and December 2014. The specimen descriptions and the reported mass per area of the 8 wall assemblies that were previously published under report numbers A1-006070.1 to A1-006070.8 have been revised in this report. The floor assemblies were built and tested between December 2014 and June 2015. The specimen description and the reported mass per area of floor specimen A1-006070-11F that were previously published under report number A1-006070.9 have been revised in this report. The following discussion section contains analyses and graphical comparisons of the tested wall and floor assemblies used to highlight key findings: In-situ TL vs. Laboratory TL Results 2. TL Results of Current Bare Assemblies vs. Previous Assemblies 3. TL Results of Walls vs. Floors 4. TL Results of CLT Walls 5. TL Results of CLT Floors 6. TL Improvement of Toppings and Resilient Membranes 7. TL Difference of Poured vs. Precast Concrete Topping 8. TL Interpolation for Floor Toppings 9. TL Improvement of Floor Coverings 10. TL Improvement of Hung Ceilings 11. TL Results of Glulam Floors The last three pages of this report contain additional test setup information for each facility. APPENDIX: ASTM E90-09 – Airborne Sound Transmission – Wall Facility APPENDIX: ASTM E90-09 – Airborne Sound Transmission – Floor Facility APPENDIX: ASTM E492-09 – Light Impact Sound Transmission – Floor Facility

Fire is an ever-present danger for building occupants. Research and experience confirm that fire safety in a house or apartment has little to do with the combustibility of the structural materials used in its construction. In fact, the occupants’ safety is far more dependent on their own awareness of fire hazards (open flames, etc.), the contents of their home (furniture, etc.), and the fire protection measures designed into the building. Minimization of sound transmission in single- and multi-family residential buildings is also an important factor to ensure occupant comfort, and is closely related to fire-resistant construction. The intent of this brochure is to demonstrate how wood frame buildings meet code requirements by providing examples of wood-based light frame building systems designed to maximize fire safety and minimize sound transmission.