Floor Soundproofing, Part 2

Understanding How Floors Transmit Noise

When we discuss floor soundproofing underlayments, the elimination of footstep noise is usually the prominent goal. Floors transmit footstep noise in the form of vibration; a shoe impacts the hard floor, creates a vibration at the point of contact and that vibration (noise energy) is radiated outward through rigid connections.

The transmission of footstep noise travels through many paths, an example is shown below.

Impact Noise diagram as related to soundproofing

With the many noise transmission paths shown in the example above, you now have a complete picture of the challenges faced when making a decision about floor underlayments for floor soundproofing. Because the ceiling below should be considered in your decision, the existing structure in your project has to be defined before the right floor soundproofing product can be selected.

This Floor Soundproofing Product Says STC 71 and IIC 71, and It Is Only $.20 a Square Foot!

Check Your Data When Choosing a Floor Soundproofing Product

As mentioned in the preceding section on IIC and STC testing, your floor soundproofing project may be much different than the tested floor/ceiling.

This inflated data is commonly shown on soundproofing literature, soundproofing websites and in soundproofing showrooms with no clarification. In the floor soundproofing industry, this is the most common misconception made to the consumer, and leads to much lower than expected soundproofing results. Please carefully evaluate your current noise situation, and select a floor soundproofing product that is appropriate. See if you can actually get a copy of the soundproofing test that was done, including a description of the complete floor/ceiling construction tested.

Warning: The vast majority of IIC floor soundproofing testing is done on 6" or more of concrete. Floor underlayment companies test their soundproofing products for large commercial or multi-family projects, and want to get the highest IIC and STC for their soundproofing product possible. Soundproofing performance tested on a 6" concrete slab will never, ever happen if your building is a wood framed floor/ceiling.

Find a company that can provide unbiased information to help with your selection of floor soundproofing products; one which carries a wide variety of products, and have no particular loyalty to one soundproofing product or the other.

There are reputable companies that have tested their floor soundproofing products in both concrete and wood frame conditions, and do state those values clearly; hopefully they can explain that the $.20/sqft product you are looking at will not work.

Click on Soundproofing to continue.