Tag Archives: noise

Faster-drying Noise Control Mat

ConstructionSpec Keene Branded News Jan 2015 IMAGE 02

Gypsum concrete poured atop Quiet Qurl 55/025 FT sound control mat.

Quiet Qurl® FT is a sound control mat designed to limit impact noise between floors. The “fast-tracking” fabric liner suspends the concrete mixture while expediting the drying time.

ConstructionSpec Keene Branded News Jan 2015 IMAGE 01

A roll of Quiet Qurl 55/025 FT with entangled net facing up. (Click to enlarge)

Quiet Qurl FT can cut down drying times up to 40 percent under the right environmental conditions. This occurs because the bottom side is thick enough for air movement, while the fabric is open enough to allow bottom drying through convection.

Quiet Qurl FT provides high-performance impact noise control, but also decreases a project’s delivery time at a crucial stage in the construction life cycle. This Class A fire-rated product enables moisture to continue evaporating from the bottom side of the topping pour, but prevents trapped moisture because it allows vapor to pass through.

When used in conjunction with 25.4-mm (1-in.) gypsum concrete, the combined system can achieve an “Extra Heavy Duty” rating from the Tile Council of North America (TCNA). Quiet Qurl FT has excellent performance at reducing sound in mid and high frequencies. Floors can be covered faster, allowing for quicker project completion in multi-family apartment and condominium construction.

http://www.keenebuilding.com/quiet-qurl-55-025-ft.aspx

 

Sounding Off on Acoustic Sealants

In the February issue of The Construction Specifier, we published the article, “Using Gypsum Wallboard for Acoustical Control,” by Ashwin L. Himat. The piece dealt with new drywall products designed to reduce noise. However, one reader was concerned there was a bigger picture to keep in mind. Steven Zalben, AIA, NCARB, LEED AP, wrote:

The use of acoustical sealant to reduce sound transmission was only cursorily mentioned. Using an appropriate sealant on both top and bottom plates, and sealing all perimeter joints of all layers, is as important—possibly, more important—than the mass. The mass primarily addresses the structure-borne sound, while sealing primarily addresses airborne sound.

We asked the article’s author to respond.

Mr. Zalben’s feedback on the use of acoustic sealants along wall and ceiling edges for dampening airborne sound transmission is quite valid. It is important to incorporate these sealants into all aspects of the gypsum-board-finishing process, and also to apply acoustical putty around all electrical boxes to prevent similar airborne sound transmission.
The function of gypsum board sealant is similar to that of the viscoelastic polymer used as the middle layer in laminated noise-reducing gypsum boards—both convert sound energy into thermal energy. The image below helps illustrate the sound transmission paths that could be present in most buildings.

SoundTransmissionI would further like to emphasize adding mass with layers of drywall to dampen airborne sound has its disadvantages. For instance, it is not as effective for improving the sound transmission class (STC) rating of the wall system, and it reduces the footprint of the usable space. Decoupling methods using resilient channels also have their limitations, as they are easy to short-circuit during installation. The newer concept of a laminated noise-reducing gypsum board achieves high STC ratings without any of the limitations that often result from adding extra layers of drywall or using resilient channels.