What Is Impact Insulation Class (IIC Rating)

Are vinyl floors loud? No, SPC and other solid floors are not too loud when the right products, materials, and installation methods are used. You don't have to stick with carpet. Noise can be reduced with the correct underlayment and installation.

First, we need to know about the floor’s Impact Insulation Class (IIC) rating.

What Is IIC Sound Rating?

Impact Insulation Class (IIC) is the measurement of a floor's ability to reduce a sound’s impact. In layman's terms, this means how much sound vibration travels, similar to the way you might hear dropped objects or footsteps in the room above. The higher the IIC class, the more sound reduction.

An IIC rating calculates the floor assembly’s noise-blocking ability. The floor assembly includes everything that makes your floor-the joists, subfloor, underlayment and floor covering.

Professionals use a tapping machine with steel-faced hammers, then strike the floor to generate an impact noise. Next, they calculate the amount of impact sound lost during the process and plot it onto a graph. Finally, the professional will reference those calculations and plot points to identify an accurate IIC rating.

What Is a Good IIC Rating?

The International Building Code requires many public structures to have an IIC rating of at least 50. Whether you’re in a residential or commercial space, strive for this number to achieve the most comfortable environment. Some assemblies, especially those with flooring underlayments, can reach an IIC rating in the 80s.

Here are three IIC classes:

IIC 50–The lowest rating and least impact, IIC 50 is typically found in stone and tile. An IIC 50 rating is applicable for ground floors. However, without much insulation between, we recommend avoiding this for second or higher levels in your home.  

IIC 60–A more medium impact, IIC 60 is typical in hardwoods, laminates and some vinyls. Hegao’s vinyl planks have this rating.

IIC 65–The highest level of sound absorption, this is reserved for thick, dense flooring like carpet and cork.   

How to Improve Your Floor’s IIC?

The best way to improve your floor’s IIC rating is by tackling different aspects of your floor’s assembly, including your floor’s joists and flooring underlayment.

Vinyl + Textile/Foam Backing To Reinforce the IIC Rating

Vinyl flooring is designed with a foam-backing design and flexible material, which is ideal for sound absorption. However, you have to seek out top-quality vinyl. Hegao vinyl plank has excellent sound absorption, offering Comfort 10x high density IXPE backing, and cork backing.