Contemporary sound control methods
Unfortunately, many contemporary sound control strategies for wall assemblies have become known for being either too expensive or problematic to install. Often, even minor installation errors can compromise the sound-control abilities of the entire wall assembly.
Using resilient channels, for instance, to acoustically isolate gypsum board from wall studs, and thereby reduce sound transmission, has been a common sound control technique since the 1960s, but has created its share of problems on the job. These sound-dampening metal strips are screwed in perpendicular to studs, and the gypsum boards are carefully screwed into the resilient channels. This requires high precision, though—a simple mistake, such as installing the resilient channels too close together or upside down, can result in the creation of a new sound transmission path negatively impacting the assembly’s acoustical performance. This occurrence is referred to as a ‘short circuit.’ Interferences with resilient channel performance can also occur during picture-hanging or pressing of heavy objects against the wall. Investigations have found that resilient channels have a 90 per cent post-construction failure rate.
Building double-stud walls or installing multiple layers of gypsum board can also be effective, but this is often costly. As with resilient channels, incorrect placement of the boards can compromise the wall assembly’s noise-reducing abilities. Additionally, these wall assembly configurations often increase the footprint of the wall, which reduces the usable square footage of the floor plan. With Toronto condo prices averaging $382,070 and a typical townhouse in Greater Vancouver now costing $563,700, more efficient use of floor space can yield real estate rewards of several thousands of dollars.
Fortunately, the emergence of new technology has permitted building product manufacturers to introduce more practical, smarter options for sound control in wall assemblies. One better example is laminated-core, noise-reducing gypsum board.
Laminated-core, noise-reducing gypsum board
Intended as a replacement for some of the contemporary sound control methods on interior walls and ceilings in residential, commercial, or institutional applications, laminated-core, noise-reducing gypsum board is a single-panel product containing a viscoelastic polymer core applied between two specifically formulated thin layers of gypsum board. The final product ends up being 13 to 16 mm (1/2 to 5/8 in.) thick—the same as traditional gypsum board thicknesses. It can be ideal for new construction or renovations over both wood and steel framing.
One sizable advantage of laminated noise-reducing gypsum boards is their ability to dampen sound transmission. The polymer core acts as somewhat of a shock-absorber that dampens board vibrations and dissipates the sound energy into thermal energy. Additionally, the boards perform well acoustically over an extended range of frequencies, resulting in higher STC ratings for wall assemblies. Therefore, this type of gypsum board is a suitable acoustic solution to specify to meet STC code requirements without materials such as resilient channels and isolation clips, which require complex installation.
Risks associated with resilient channels and isolation clips are eliminated when laminated noise-reducing gypsum board is directly applied to framing, resulting in more consistent and predictable acoustical performance. However, the laminated core noise-reducing gypsum board can be used to achieve extra sound transmission control in wall assemblies where resilient channels or isolation clips are desired. In such cases, the material helps reduce the negative impact of any short circuits.
Offering the same level of sound control as traditional multi-layered gypsum systems in the form of a standard-sized laminated noise-reducing gypsum board allows project teams to build effective noise-reducing walls with less material and no special tools. Additionally, the project will gain valuable square footage, cut construction time, and reduce material and labour costs. Minimal use of material also means a more sustainable structure in line with today’s green building practices.
Assemblies utilizing a single layer of laminated core noise-reducing gypsum board have been tested and proven to meet or exceed the acoustic performance of assemblies using double layers of traditional gypsum board. The high-performance gypsum board is therefore quite effective in applications where acoustic management is needed to dampen sound energy and significantly improve sound attenuation through walls and ceilings.
