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Single Wood Stud Wall -2x4 Stud 2 Layers 1/2" Drywall Each Side One Side on Resilient Channel A - Without Insulation B - R-11 Batt Insulation

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The purpose of resilient channel is to provide a flexible connection to mechanically decouple the partitions on either side of the framing. When the panels are already separately or flexibly supported, the addition of resilient channel does little to improve the transmission loss. Thus there is little or no advantage in adding channel to double stud, staggered stud, or single lightweight metal stud construction.

Resilient channel is not effective when it is installed between two layers of gypboard, since the air gap is small (typically 13 mm or 1/2") and the trapped air creates an air spring, which makes an additional mass air mass resonance. If a single metal stud wall with batt insulation has drywall on each side and another layer is added on resilient channel, the result is worse than without the additional layer (Green and Sherry, 1982).

Resilient channel is utilized in floor-ceilings more often than in walls since it is compromised by mounting bookcases or cabinets to the supporting studs. It is only effective in isolating small-amplitude vibrations that are much less than the structural deflection under load. It is generally not effective in preventing the transmission of low-frequency sound created by the large-scale deflection of long-span joists under a dynamic load. However, it can provide an improvement at high frequencies to both the STC and IIC ratings in floor-ceiling systems. In floor-ceilings, it should be installed so that the ceiling gypboard is butted

Figure 10.8 Transmission Loss of Staggered Stud Walls (California Office of Noise Control, 1981)

Staggered Wood Stud Wall 2x4 Studs an a 2x6 Plate 1 Layer 5/6" Drywall Each Side A - Without Insulation B - R-1

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