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Sound Transmission Class

SONOpan goes beyond standard building code and has assemblies that start at an STC rating of 56, and go upwards depending on the wall assemblies.

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Sound Transmission Class

Sound Transmission Class (STC) is a standardized rating measuring reduction in sound decibels (dB) based on different wall or ceiling assemblies. STC accounts for sound measured between 125 Hz to 4000 Hz.

Sound decibels (dB) are a measure of sound intensity. In simpler terms, sound decibels are measured as the magnitude of the fluctuations in air pressure caused by sound waves. The STC rating is measuring the percentage change in dB reduction.


SONOpan STC ratings

Sound Scale

Scale of sound dB

0 dB Silence
60 dB A business office
80 dB A moving car
100 dB A plane taking off

To bring down the decibels of sound, you need distance and obstacles in the path of moving sound, like a wall, ceiling or sound proof board.

When it comes to reducing dB that travel in a housing unit with separating walls, the National Building Code of Canada requires a wall to have a Sound Transmission Class of 50. There are no sound transmission requirements for free-standing single-family homes.

Insulation Isn’t Enough

It is highly recommended that SONOPAN be used in conjunction with insulation to reduce sound travel. Insulation plays a key role in soundproofing by capturing certain frequencies and stopping resonance (echoing) in an empty cavity, but SONOpan soundproof boards for walls & ceilings will prevent the majority of sound from traveling.


For more information on Sound Transmission
Class and SONOpan sound proof insulation board, please contact us.

Increasing Sound Transmission Class

You can use Resilient Channels and/or isolation clips to increase Sound Transmission Class Ratings for any room.

If using resilient channels when adding SONOpan soundproofing, install them perpendicular to the ceiling joists every 12” and/or according to the manufacturer’s specifications. Install channels 6” from outer walls and every 12” on center in between.

For walls fastened perpendicular to the studs every 24” and according to the manufacturer’s specifications install the 1st channel 2” from the ground and every 24” on center stopping 6” from the ceiling.