Best options for noise control in mulit-family dwellings
Acoustical separation of units is a most critical component in the design of multi-family housing. Our flooring underlayments are engineered with a recycled fiber blend to help aid with noise control and impact sound from traveling to rooms below. All of our fiber underlyaments have LEED building benefits.
Insulation between the ceiling joists and the wall studs and resilient channel attachments of the drywall to the structure help in mitigating the sound. Floors have their own complications. An understanding of the type of noise, rating systems, codes and methods to reduce the sound transmission is important in determining the best solution for your residence.
Types of Noise
There are four types of noise that affect the performance design of the floor/ceiling . The first two, airborne and impact noise, are something that you as a tenant can mitigate.
- structural deflection, and
- floor squeaks.
Airborne noise. This noise is transmitted through the air and intervening partition and floor systems. Sources would be a voice, a barking dog or a television. Solutions include adding: absorptive materials (ie. wall and ceiling insulation); an air space by attaching the drywall with resilient channels, and; mass, as with multiple layers of drywall.
Impact noise. This originates when one body strikes another, ie. footsteps, hammering, and falling objects. This noise can travel through the structure with little loss of energy if the structure is rigid and continuous. Solutions include soft flooring materials that absorb impact (ie carpet and pad) or resilient materials used as an underlayment for hard materials.
Structural deflection. This noise is different in that an impact load on the floor causes the structure to deflect such as the noise of a sumo wrestler living upstairs. This is beyond a tenant’s control as it involves the stiffness of the structure and so design of the building.
Floor squeaks. These occur from rubbing, as in the case of poorly installed wood planks. This can be corrected with the installation of a proper sub floor.
Multi-family Housing Codes
Using the STC and IIC Rating Systems
The sound rating classifications, established by HUD and the National Bureau of Standards, are recognized by building construction regulatory bodies and agencies and found in our building codes.
As there are a number of components in the design of the floor/ceiling assembly, the resultant STC and IIC ratings are based on testing the total assembly. To properly design your floor’s acoustics, you will need to know the existing floor and ceiling structure of the building.
Another method would be to find out the Delta IIC rating (ΔIIC) which is the rating for the material itself without considering the floor/ceiling assembly. This will give you a better comparison between the products you are evaluating without the contributions of concrete, sound rated ceilings, and other components.