Last night on one of the home improvement shows, a couple had purchased half of a new duplex- a townhouse. They found they could easily hear the sound of the neighbors talking next door when they were in their kitchen. So the contractor had a sound expert come in & measure the sound. The results? They found the STC ([SIZE=-1]Abbreviation of Sound Transmission Class, a single number rating for describing sound transmission loss of a wall or partition) [/SIZE]was not within acceptable limits as a boom box playing loud in one half of the duplex was easily heard in the other.
So the contractor tore open the kitchen wall and found a double sheet rock wall with a little insulation in place where a construction access door way had originally been. The wall met minimum spec, but for a few more dollars, there would have never been a problem.
The fix was to use a sound absorbing/blocking material inside the wall and then to cover with a sheet rock-like material which was equivalent to 9 sheets of sheet rock in reducing sound transmission. The key was some type of elastic material between the outer layers of this special wall material.
The easiest sound to block are high frequency sounds. the low frequency sounds can be a challenge. Anyhow, once the contractor completed the work which also included placing a special material over every outlet & switch box, the sound transmission between the two units went from being loud to where it was no longer measurable.
Tony
So the contractor tore open the kitchen wall and found a double sheet rock wall with a little insulation in place where a construction access door way had originally been. The wall met minimum spec, but for a few more dollars, there would have never been a problem.
The fix was to use a sound absorbing/blocking material inside the wall and then to cover with a sheet rock-like material which was equivalent to 9 sheets of sheet rock in reducing sound transmission. The key was some type of elastic material between the outer layers of this special wall material.
The easiest sound to block are high frequency sounds. the low frequency sounds can be a challenge. Anyhow, once the contractor completed the work which also included placing a special material over every outlet & switch box, the sound transmission between the two units went from being loud to where it was no longer measurable.
Tony