Understanding STC Ratings

STC is an acronym for sound transmission class, which is a method to measure how well something attenuates sound traveling in space. Sound waves travel through mediums by vibrating molecules in the matter, resulting in different mediums conducting sound waves at different rates. Solid mediums will produce sound at a higher rate due to the molecules being close together. Gaseous mediums will result in a lower-rated sound due to their molecules being farther apart.

When analyzing the STC performance of wood doors paired with aluminum framing systems, each of the core components must be analyzed as it can affect the overall result of the score. Aluminum frames and window panels are all manufactured from the same type of mediums, meaning they are all classified as solid mediums. This indicates that each of these components that make up the framing system will transmit sound waves at approximately the same rate. 

The next step in determining the STC rating is combining the components to see how sound travel will be affected when the pieces are interlocked. Putting together the components of the assembly will result in potential sound paths, which will affect the STC rating of the overall system. The aluminum framing may have air pockets that exist within the extrusion channels, and the doors used with the assembly are the largest variable factor that can change an STC rating. When placing the pieces of the system together, the STC rating of the product will begin to decrease. 

To improve the system’s STC rating, manufacturers must ensure the system is designed to eliminate as many sound paths as possible. Additionally, the door component of the assembly must be analyzed since it is the biggest factor in the change of STC ratings. Wood door frames must meet certain requirements in order to be classified with high-performance STC ratings. 

Frameworks Manufacturing is pleased to offer to its distributors a new option never before available in the aluminum frame industry. The Frameworks Type II aluminum frame system has now been tested with STC-rated wood doors from Graham and Maiman. Designed specifically for interior applications, this new solution consists of an STC 35 architectural wood door paired with Frameworks aluminum frames. An aesthetically pleasing industry first that allows designers to achieve the clean lines of aluminum frames with the beauty of wood doors.

Frameworks offers a selection of aluminum framing systems to achieve the client’s vision for their office space. Browse our website or download our brochure to learn more about the products we offer and what we can do for you. For additional questions or to discuss your manufacturing needs, contact one of our specialists today!