St Cloud Window

Ever wonder why STC ratings for doors are important? 

07/22/2021

Simply stated noise impacts our health. Street noise, people, electronics – everywhere we go there is noise and it can damage more than your hearing. Research shows that excessive noise increases the level of stress hormones and is linked to increased anxiety, depression, high blood pressure, heart disease, and stroke – even in small amounts.

To create quieter indoor spaces, builders, architects, and owners can opt for acoustically rated products.

Specifically, doors can keep sound from moving in or out. They are typically the thinnest point in a wall and the weakest link when it comes to blocking sound or reducing noise. For example, a door in an 80 square foot wall potentially represents close to 20% of the area and the door itself represents the weak point in the wall for sound to penetrate.

However, some doors are much better at blocking sound than others. Sound Transmission Class (STC) rating for doors measures how successful it will be at blocking sound transfer. Selecting a door with an STC rating of 34-36 would block low speech, according to the National Wood Window and Door Association.  However, to block loud speech, a door needs an STC rating of from 40-50. For excellent noise blocking, the door needs an STC of 50-60 and gaskets to block noise from traveling through gaps.

Hanley Wood University acoustic course suggests:

    • Acoustical doors meet most building STC performance requirements for a multitude of projects and applications, including schools, universities, government buildings, private offices, auditoriums, theatres, and libraries.
    • STC ratings vary depending upon the manufacturer, and specific construction and acoustical door thicknesses may vary.
    • Lite kits must be installed at the factory for STC rating.
    • Specify acoustical doors that have been laboratory tested per the most recent version of ASTM E-90, Standard Method for Laboratory Measurement of Airborne Sound Transmission.
    • Testing of the entire opening system is conducted, which includes the door in combination with properly installed gasket seal systems (frame gaskets and door sweeps), and frames.
    • Tests should only be performed in an operable state to accurately simulate on-site performance.

Acoustic doors reduce the amount of outside noise that seeps into buildings. Look for STC and OITC ratings to find the optimal levels of noise mitigation.
Our acoustic window and door experts at St. Cloud Window can help you find the best window for your needs – request a quote today for more information.

At St. Cloud Window we know every project begins with a challenge or an idea of what a building might be. We bring that vision to life with our distinctive design aesthetics, precision performance, and design-to-delivery support. Learn more about how our products can deliver on your design objectives and site requirements here. Then, check out our full line of historic replica and acoustic window products, and get in touch for more details about any of our high-performing commercial window products.