Understanding STC

Understanding STC

STC – Sound Transmission Class

Understanding STC

What is STC?

STC is a unit of measure of how much airborne sound energy is diminished across a boundary wall or partition. It is mostly used for interior spaces. With STC, the higher the rating means the greater the sound attenuation capabilities of the interior partition. Opening glass walls with acoustically separated framing, specialized gaskets, and sound enhanced glass make excellent, flexible acoustical barriers within interior space.

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Understanding STC laminated glass

What is STC?

As innovation continues to drive the DNA of NanaWall products, it also presents a multitude of glass options to meet the sound control needs of architectural design. With standard monolithic glass, the sound transfer reduces as the thickness of the glass increases. Yet cost and weight can be a hindrance.

Laminated glass is a very effective means of improving the sound rating. With laminated glass, two layers of monolithic glass are sandwiched together with a thin layer of plastic—called a sound enhanced interlayer. This glass type greatly enhances sound attenuation. Lastly, insulated glass with two panes of glass separated with an air cavity. The glass type and airspace combination are seemingly endless.

  STC  What Can Be Heard


 Normal speech is easily understood


 Normal speech is audible but not understood


 Loud speech is understood


 Loud speech is audible but not clearly understood


 Must strain to hear loud speech


 Loud speech is not audible

Just Right—Specify Only What is Needed

NanaWall opening glass walls can be specified with various acoustic glass options from monolithic to sound enhanced laminated to double IGU to meet noise-reduction requirements.

Our sound-rated products have been interpolated based on true physical testing with three different glass types. STC rating and calculations are per ASTM E413 and DIN EN ISO 717-1. Our products are tested by certified and accredited independent laboratories to meet the highest standards per ASTM E90-09 and DIN EN ISO 10140-1, 2, 4 & 5 test procedure.