With the array of underlayment products in today’s market, promoting high IIC and STC ratings, do you know what you are truly getting for your money? More importantly, do you understand the ratings? Well, let us dissect and educate you on the products.
Much of the inventory available today provides specs with higher ratings but not all may meet your criteria. There are many factors to consider such as slab thickness, ceiling suspension, and HOA requirements. Noted below is a side by side comparison of the most popular underlayment to date:
Now, what does all this mean?
Most of what’s in the market consists of a 6” slab. Taking into consideration that slab thicknesses vary, this will change the variable (decibel rating). A 6” slab has a decibel rating of 27(+/-). If you are working with an 8” slab, obviously, it will translate to a higher decibel rating; approximately 7 to 9 dB. While this is great, if you are not working with this thickness, then your underlayment will not meet requirements. Furthermore, suspended ceilings add another 14 decibels to the ratings which, again, most properties do not have.
In conclusion, it is important that you obtain test results with your specs. Read the specimen description. What other products were used (i.e., specific adhesive, acoustical sealant, additional underlayment)? These play a vital role in the final outcome of the testing. This is not intended to discredit the wide range of acoustical underlayment products out there but rather educate you on them and provide variables to consider on your next project. Know and understand what your clients needs are.