The Impact of a Poorly Isolated Floor

The Impact of a Poorly Isolated Floor

Do you need an IIC test? Do your tenants complain of hearing their neighbors above?  Does your old building meet modern building codes for sound isolation?  Do you want to make sure that you have the sound isolation that you paid for?  Maybe you need an IIC test. What is an IIC rating? The IIC (Impact Insulation Class) is a rating of the impact sound on a floor that is audible in the room below.  A higher number means better impact sound insulation. What is an IIC test? An IIC test is done by an acoustic engineer using ASTM Standard E1007 – Standard Test Method for Field Measurement of Tapping Machine Impact Sound Transmission Through Floor-Ceiling Assemblies and Associated Support Structures.   The test can determine the IIC of the floor-ceiling that separates condominiums, apartments, or offices. How is an IIC test done? The test requires access to the both rooms – the one above the floor and the one below.  A standard tapping machine bangs on the floor to generate impact sound (see ours in action).  First, while the tapping machine is banging away, the sound level is measured in the room below.  This is repeated with the machine in four different positions on the floor. Then the reverberation time, or T60, is measured in the room below.   The T60 is used in IIC calculation to “normalize” the measurements to a standard condition.  This allows us to compare an IIC measured in a “dead” room to one measured in a “live” room. Next, the airborne sound isolation of the floor-ceiling is measured.  Usually a loudspeaker and amplifier generate pink...
What’s a Tapping Machine?

What’s a Tapping Machine?

The new Tapping Machine is here!  The new tapping machine is here! Okay, maybe you’re not an Acoustic Engineer and not as excited as I am, but just look at this beauty in action. What is a tapping machine?  It’s only purpose in the world is to measure the Impact Insulation Class (IIC) of a floor-ceiling.  The IIC is a measure of how much you hear someone walking around in the condominium or apartment above you.  The machine bangs on the floor by dropping five metal “hammers” over and over again.  If you look close you can see the hammers dropping under the machine. The weight of the hammers, the hammer spacing, the height from which they are dropped, and the time between impacts are all defined in ASTM Standards E492 and E1007, and ISO Standard 140-6.  ASTM E1007 is the Standard Test Method for Field Measurement of Tapping Machine Impact Sound Transmission Through Floor-Ceiling Assemblies and Associated Support Structures.  This is the standard we use to do field tests in apartments, condos, and other buildings. Now don’t you wish you had a tapping...