What is it? Impact Insulation Class is an acoustical rating used to quantify impact sound absorption.

Impact noise will travel through a structure that does not have a resilient material as part of the construction assembly.

Impact noise will travel through a structure that does not have a resilient material as part of the construction assembly.

What is it used for? This rating system is used for floor/ceiling arrangements. Some arrangements include floor underlayments, which go under carpet, vinyl, or hardwood in multi-level buildings to absorb impact noise such as footfall, keeping the noise and vibration from transferring to the ceiling below. Assemblies with these acoustical underlayments have a higher IIC rating because they block more impact sound. So IIC ratings are assigned to floor underlayments not only based on the product’s material, but the floor assembly on which it is installed.

What underlayments carry have IIC ratings? Acoustical floor underlayments. Acoustical Solutions offers a variety of acoustical floor underlayments including EnkaSonic and Iso-Step.

EnkaSonic Floor Underlayment is a material made up of extruded nylon filaments which form a 3-dimensional core that has a non-woven fabric heat bonded to its upper surface.

Adding a resilient material to the construction assembly will help reduce or eliminate structure borne sound like foot fall noise.

Adding a resilient material to the construction assembly will help reduce or eliminate structure borne sound like foot fall noise.

The durable, yet pliable, construction of Enkasonic sound control matting lowers both structural and airborne sound transmission by its ability to convert and store vibrational energy. EnkaSonic has an impressive IIC and STC (sound blocking) rating for all assemblies, but carries no STC rating as a stand-alone material. Iso-Step Floor Underlayment is an environmentally friendly rubber-based product made from recycled tires. It offers credible sound reduction for structure borne noise, with exceptional IIC ratings for all assemblies and does help increase the STC rating when used in a soundproof flooring assembly.