If you’re prepping for a flooring project and researching underlayment, a good place to start is by recalling your first apartment. If you’re lucky, you’ll have no recollections of noisy neighbors or dogs that seem to be all lungs and toenails. For most people, however, unwelcome noise is either an unpleasant memory or a very painful present-day reality. But it doesn’t have to be that way. You can prevent acoustically awkward spaces by choosing an underlayment that offers superior sound-absorbing qualities.
Acoustical ratings may seem overly technical, but they are simply a measurement of two different types of sound: impact and airborne sound transmission.
Impact Insulation Class (IIC) refers to the ability to block sounds from impact. Imagine your upstairs neighbor repeatedly dropping their cell phone on the floor, your teenager taking up weightlifting, or your daughter playing dress-up and clomping around in heels right above your home office. IIC ratings measure the number of decibels your flooring resists. The higher the number, the quieter the floor.
Delta IIC tests the impact insulation of the underlayment alone. Delta IIC is basically comparing two IIC tests on the same concrete subfloor. A higher number shows better performance. One test measures impact sound on a bare concrete floor. The other test measures sound on the same subfloor with underlayment only. The difference between the two tests is the Delta IIC rating, a value notably lower than IIC ratings because the value of the subfloor itself is eliminated in the comparison.
Sound Transmission Class (STC) tests airborne sound transmission. To understand this rating, imagine your upstairs neighbor is hosting fantasy football tournaments, your teenager has quit fitness and is learning the drums, and your daughter is obsessed with Selena Gomez. Now, imagine these sounds being absorbed by the flooring beneath them. This is sound transmission, and this rating measures the number of decibels that airborne sound is reduced.
So, what should you look for? Start with the following benchmark: For both IIC and STC, a rating of 50 or above will satisfy the minimum requirements of the International Building Codes (IBC). Anything above that is extra protection for your peace and quiet.
In certified third-party laboratory testing, Eco Cork Foam® (ECF) received the following ratings, which are among the highest in the industry.
IIC (Impact Insulation Class) – 73 dB
Delta IIC – 23 dB
STC (Sound Transmission Class) – 67 dB
ECF is manufactured in North Carolina by Palziv, North America. Palziv brings together world-class science and engineering to deliver innovative products, materials and services for the construction, building, automotive, recreational, medical and packaging industries. Every day, we strive to grow our community, working with others to seek sustainable, innovative, market-driven solutions that promote better, safer, and healthier lifestyles and protect the environment for generations to come.