Silver Lining Windows & Siding

Abbreviation for Sound Transmission Class Rating. When glass is used on the building interior, the sound transmission classification (STC) value can be used to categorize the glass performance. The STC rating is a single-number rating system for interior building partitions and viewing windows. The STC rating is derived by testing in accordance with ASTM E90, 'Laboratory Measurement of Airborne sound Transmission of Building Partitions". The STC value is achieved by applying the Transmission loss (TL) values to the STC reference contour of ASTM E413, "Determination of Sound Transmission Class". The STC rating is a basis for glass selection. Its original intent was to quantify interior building partitions, not exterior wall components. As a result, it is not recommended for glass selection of exterior wall applications, since the single-number rating was achieved under a specific set of laboratory conditions.

An STC rating is a standard defined by the American Society for Testing and Materials (ASTM). A higher STC rating indicates a greater sound-reducing effect. For example, single-pane glass has an STC of 26, which is considered low because voices from outside can be clearly heard. Dual-pane insulating glass, with an air space between the panes, has an STC of 28. Even better, laminated glass has an STC of 35. Laminated glass can help homeowners turn down the volume indoors. At this STC rating, loud speech from outside can be heard but not clearly understood. Sound-Tite Windows with an Optical grade acrylic with a thickness of .236" (1/4") combined with a single pane of glass has an STC Rating of 41. At this STC traffic noise is reduced by over 80-90% to the human ear. Sound-Tite Windows with an Optical grade acrylic with a thickness of .236" (1/4") combined with a double pane of glass has an STC Rating of 48-53. At this STC traffic noise is reduced by over 90-100% to the human ear and loud talking is completely eliminated.

The Table Below compares STC Ratings


Single Pane Window = STC Rating = 26


Double Pane Window = STC Rating = 28


Single Pane Window with Sound-tite Window=
STC Rating = 41


Double Pane Window with Sound-tite Window=
STC Rating = 45-53