Underlayment for Condos
Q: I currently live in a condo and my upstairs neighbor wants to install a wood or laminate floor. They currently have the builder supplied carpet and underlayment. While we can’t hear them talking, we can definitely hear them walking and other thumping noises from above. We are reluctant to give permission for them to install new flooring since we feel the noise might increase. Is there a solution to letting them install wood/laminate flooring and reduce to noise we hear now? Is cork underlayment the solution?
thanks,
Warren
A: There are two very important factors to noise transmitting from an overhead floor, STC and IIC. Now let’s break down these terms, STC or Sound Transmission Control, is a measurement of how much sound transfers through the floor. IIC or Impact Isolation Control measures how well something absorbs impact. When combined, these two ratings will give you an idea of how much noise you will hear from ambient sound, like talking, and impact, such as walking.
Finding carpet statistics is very hard, but roughly put your average carpet pad and carpet will give you an STC rating around 55-60 with IIC ratings around 75. Carpet is the king of impact control, which is why it is so commonly used in apartments (it can also be very cheap). With 6mm cork you will have STC ratings of 51 and IIC ratings of 50 – so you have similar sound control, but much less impact control. Now the other typical underlayment option that you can look into is something like Sound 6, which will give you STC ratings of 73 and IIC ratings of 61-63.
This leaves a fairly tricky scenario, but a solution that has been recommended in the past is to use 6mm cork as a substrate and then put Sound 6 over it. This combines all of the benefits of both, which when combined should give you the best solution for getting a hardwood floor to perform at the levels of carpet. Keep in mind that regardless, this will still be a hard surface floor, and some noise will change, but with this underlayment set up over a solid floor (might want to avoid some of the cheaper laminate floors), you should be able to satisfy both your wants for sound suppression and your neighbor’s want to have a wood floor.