This client report on the acoustics research component regarding sound insulation of elements and systems for mid-rise wood buildings is structured into a main part and four appendices. The main part outlines the background, main research considerations and summarizes conducted research and major outcomes briefly. It is structured like the Acoustics tasks in the Statement of Work of the Mid-rise Wood research project to identify accomplishments. For details on the research, testing and results, the main part references to four appendices that contain more details including test plans, test methods, specimen descriptions and all test data that is vetted so far.
This report summarizes the acoustics research component regarding sound insulation of elements and systems for the research project on mid-rise and larger wood buildings. The summary outlines the background, main research considerations, research conducted and major outcomes. Further details of the design and the results can found in the appendix of Client Report A1-100035-02.1 [1].
The goal of the acoustics research components was to develop design solutions for mid-rise wood and wood-hybrid buildings that comply both with the current National Building Code of Canada (NBCC) 2010 [2] requirements for direct sound insulation and with the anticipated requirements for flanking sound transmission in the proposed, 2015 version of the NBCC. In addition, the design solutions were to provide better impact sound insulation while still achieving code compliance for all other disciplines (interdependencies) as identified in the final report of the scoping study conducted in FY 2010/2011 [3]
This report contains the transmission loss (TL) results measured in accordance with ASTM E90-09 and the normalized impact sound pressure level (NISPL) results measured in accordance with ASTM E492-09 of 13 cross-laminated timber (CLT) floor assemblies and 5 glulam floor assemblies. The report also contains the nonstandard impact sound pressure level results measured on 6 different small patch specimens.
Summary tables containing the specimen number, sketch, short description, the sound transmission class (STC) and impact isolation class (IIC) ratings, as well as, the page number of the detailed test reports are provided starting on page 5.
A brief analysis of the floors tested as part of this test series is provided after the summary tables on page 9. The standard test reports of the tested floor assemblies begin on page 16. The floor assemblies were built and tested between January and April 2016.
Structure-borne sound transmission across a cross-junction of double solid timber walls with a solid timber floor was analyzed in a recent research project. Both, the double walls as well as floor slab, were of so-called Cross Laminated Timber (CLT). The floor slab was continuous across the junction for structural reasons and thus, formed a sound bridge between the elements of the double wall. To gain a better understanding of the contributions of sound transmission between the wall and floor elements from the different possible paths, a thorough analysis was conducted. Hereby, direct sound transmission through, and radiation efficiencies of, the CLT elements were measured in a direct sound transmission facility; as well as, structure-borne sound transmission between CLT elements was measured on a junction mock-up. The experimental data was used as in-put data and for validation of the engineering model of EN 12354/ISO 15712 for the prediction of flanking sound insulation in buildings. The test procedures, analysis and results of this research project are presented here.
Cross Laminated Timber (CLT), which is well suited for construction of tall buildings, is becoming a more popular construction material in North America. However, to ensure comfortable living conditions, sound insulation measures are necessary. The study presented here compares results of direct impact sound insulation of 5- and 7-ply CLT floors covered with different a concrete toppings on various interlayers. Improvements of up to 21dB in Weighted Normalized Impact Sound Pressure Level (Ln,w) were observed using a newly proposed reference floor for CLTs. Furthermore, the improvements of floor coverings on CLT floors are compared to those achieved on other types of construction, such as the reference concrete floor. The improvements of Ln,w tend to be higher on the concrete floors than on the CLT floors tested. These and other findings will be presented.
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.
In recent years Cross Laminated Timber (CLT) was introduced as an emerging building system in the North American market. CLT elements consist of multiple layers of wooden beams that are laid-out cross-wise and laminated together to form solid wood panels for floors and walls. As part of a multi-disciplinary research project a comprehensive study was conducted on the impact and airborne sound insulation of this type of elements in order to create a data base that allows building designers to predict the acoustic performance of CLT systems. Parametric studies were carried out on the direct impact airborne sound insulation of CLT floor assemblies (with/ without various floor topping and gypsum board ceiling variants), on the direct airborne sound insulation of CLT walls (with/without gypsum board linings), as well as on the structure-borne sound transmission on a series of CLT building junctions. The results were then used as input data for predictions of the apparent impact and airborne sound insulation in real CLT buildings using the ISO 15712 (EN12354) framework that was originally developed for concrete and masonry buildings. The paper presents the prediction approach as well as results of prediction and measurement series for apparent impact and airborne sound insulation.
