How To Understand Sound Ratings In Flooring

There are three different standards for rating sound transmission.

How to understand sound ratings in flooring.

This is called impact sound transmission. The floor covering industry considers the sound insulation very important in living areas such as multi family or single family dwellings. Sound transmission class or stc is an integer rating of how well a building partition attenuates airborne sound. The third covers room to room transmission more appropriate for walls.

The uniform building code ubc contains requirements for sound isolation for dwelling units in group r occupancies including hotels motels apartments. Iic is measured in terms of sound impact or how well sound vibration travels through a floor to the room below. The lowest iic rated floors ceiling assemblies come in at around 25 and the highest rated systems can come in at 85 and up. Sound transmission class stc is an integer rating of how well a building partition attenuates airborne sound in the usa it is widely used to rate interior partitions ceilings and floors doors windows and exterior wall configurations see astm international classification e413 and e90.

Sound control standards were developed to regulate the amount of noise allowed to penetrate through common walls and floors within dwellings and are used to compare product qualities. Each defines a different way in which sound is transmitted. â under the current sound rating system the higher the number the better sound suppression quality. The stc rating for a six inch concrete sub floor is 52 55.

This sound rating increases to stc 42 45 with steel studs. Impact tests require a tapping machine to create impact sound directly on the floor construction in the source room. The first two measure flooring sound transmission. The stc rating for a basic wood structure floor ceiling is stc 40 43.

Generally an iic rating of 50 will satisfy the building code requirements. Floor coverings with a high iic rating help to reduce impact sound transmissions to lower levels thus reducing or eliminating those bothersome noises. The impact sound pressure level is calculated giving the floor an impact sound insulation rating. Laminate makes the most noise both when walked on and in echoing sound due to its hard surface and light weight but can be a good choice for sound reduction when used over a quality underlayment.

In the us it is widely used to rate interior partitions ceilings floors doors windows and exterior wall configurations. Measurements are taken in the receiver room in third octave bands from 100hz to 3150hz. Outside the us the sound reduction index sri iso index is used.