Sound Transmission Class (STC)
Door Glass & Enclosed Blinds

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Definition

STC is expressed in decibels (dB) and is used to measure a building material's ability to reduce sound. A higher STC rating translates into more reduction in sound. Laboratory testing is used to measure the resistance of partitions such as walls, windows, or entry doors to the passage of sound.

The material with the lowest resistance to the passage of sound limits a partition's STC value. Poor construction practices can also nullify a partition's sound reduction properties. Cracks due to improperly fitted doors or windows can be a prime source of sound leakage.


STC Values

ODL conducted third party IAS-accredited lab testing on a range of doorglass configurations. All of the doorglass samples were 22" x 64" except the sliding patio door blind which was 33" x 74". These sound transmission loss tests were conducted in accordance with ASTM E 90. The Sound Transmission Class (STC) rating was calculated in accordance with ASTM E 413. Test results and benchmark values are presented below.

Family Configuration STC Comment Date
Tested
Test Report
Expiration
Deco Decorative glass with caming 31 Third party tested
(692 K) Adobe PDF
4/6/11 4/6/15
1-lights,
grilles
between
glass,
external
grilles
1/2" IG, clear glass 1-light,
1/4" air space, Intercept® spacer
27 Third party tested
(692 K) Adobe PDF
4/6/11 4/6/15
1/2" IG, clear glass, external grille,
1/4" air space, Intercept® spacer
27 Third party tested
(774 K) Adobe PDF
8/29/11 8/29/15
1" IG, clear glass 1-light,
3/4" air space, Intercept® spacer
28 Third party tested
(692 K) Adobe PDF
4/6/11 4/6/15
1" IG, clear glass, grilles between glass,
3/4" air space, Intercept® spacer
29 Third party tested
(774 K) Adobe PDF
8/29/11 8/29/15
Simulated divided light,
grilles between glass with external grilles,
3/4" air space, Intercept® spacer
30 Third party tested
(774 K) Adobe PDF
8/29/11 8/29/15
Severe
Weather
Severe Weather,
1-light door glass
35 Third party tested
4/9/14 4/9/18
Severe Weather,
decorative door glass
38 Third party tested
(692 K) Adobe PDF
4/6/11 4/6/15
Blinds Triple-glazed, grilles between glass blind,
with Intercept® spacers,
slats lowered and closed
34 Third party tested
4/9/14 4/9/18
Dual-glazed blind, with Intercept® spacer,
slats lowered and closed
38 Third party tested
4/9/14 4/9/18
Sliding patio door blind,
Intercept® spacer,
slats lowered and closed
28 Third party tested
4/9/14 4/9/18
Door and
window
reference
information
3' x 7' steel door,
1-3/4" thick with polyurethane core
26 From HUD Noise
Notebook*
30" x 48" aluminum clad
casement window,
1" IG with 1/8" panels
29 From HUD Noise
Notebook*
* Source: HUD Noise Notebook chapter 4 supplement, Sound Transmission Class guidance