Impact sound transmission
Testing of in-room flooring impact sound is fairly new, but the testing and analysis of impact sound transmission from a room above to a space below has been common for decades. Common industry standards used to determine the severity of impact noise transferred from a source room to a space below are impact insulation class (IIC) and delta impact insulation class (ΔIIC) ratings. These standards play a key role in determining the effectiveness of flooring and flooring underlayments when addressing impact sound transmission from footsteps, rolling carts, and dropped items.
IIC ratings depend on the design and construction of an entire floor/ceiling assembly, but they can be improved significantly with the right selection of flooring and/or acoustical underlayments. Higher IIC ratings mean lower noise levels in the room below.
Where IIC ratings measure the performance of an entire floor/ceiling assembly, ΔIIC ratings just measure the impact insulation performance of floorcoverings and underlayments when tested on a standard 152-mm (6-in.) concrete slab. A ΔIIC rating is essentially the difference in IIC ratings between the bare 152-mm concrete slab, and the 152-mm concrete slab with the flooring and underlayment. For example, if a bare 152-mm concrete slab has a rating of IIC 29 and the addition of flooring and underlayment result in an IIC 52, the ΔIIC rating would be 23. Since ΔIIC ratings are based on a standard 152-mm concrete slab, they provide a better apples-to-apples comparison of the impact insulation provided by flooring and underlayment. However, when comparing underlayments, it is important to note the finish floor tested on top of the underlayment also affects the ΔIIC rating, so it is advisable to only compare underlayment tests using similar finish flooring materials.
The single composition material allows for improved acoustic performance due to the capability of using a thicker underlayment. This allows one to combine a thicker underlayment with sheet vinyl (or another top layer material) and receive the performance benefits of both the vinyl and the underlayment.
Loud sound levels can have a negative impact on patient wellness, health-care provider efficiency, and overall quality of care. To reduce sound levels and improve patient experience and outcomes, many health-care facilities are looking to update their site designs and building materials, including flooring selections. When evaluating health-care flooring options, it is important to consider reducing noise levels while maintaining high standards of cleanliness to provide safety and comfort to patients and health-care providers. Studies show resilient flooring surfaces with rubber underlayment improve acoustical issues without creating a hygiene risk. These materials contribute to a quieter environment more conducive to healing while supporting health-care providers in their delivery of quality care.
Mark Huxta is the director of healt-hcare sales for Ecore. An industry veteran with more than 40 years in the flooring industry, Huxta offers extensive experience and knowledge to his clients with a focus on issues affecting patients, residents, and health-care providers. He was a founding board member of the Delaware Valley Green Building Council and is a member of the HealthPoint Advisory Board. Huxta can be reached via e-mail at email@example.com.
Sharon Paley was formerly an acoustic engineer with Ecore. She graduated with a master’s degree in mechanical engineering from Boston University and is a full member of both the Acoustical Society of America (ASA) and the Institute of Noise Control Engineering (INCE).