I went over to the warehouse this morning to ship out items for one of our final trade shows of the year. I walked back to the door production area, and they were working on some of the Sound Transmission Class (STC) doors that we assemble for various government applications.

This got me thinking, “Self, you haven’t written about STC doors on the blog yet!” So, allow me to dive into the wonderful world of soundproof doors with you.

What Does STC Mean?

STC is the abbreviation for sound transmission class. There are various STC ratings a door can have, which were developed by ASTM International.

The higher the rating, the less noise that travels through the door. I’m almost positive my college apartment doors had a STC rating of 20. I could hear everything, which made it quite frustrating when I was trying to study or sleep (yes, I was a bit of a nerd).

The STC doors we make for government applications are the exact opposite of my apartment doors. The government doors have a STC rating of 50 or higher.

How Are STC Doors Made?

STC doors and frames come in a variety of materials, the most prominent are wood and metal.

Wood doors inherently have great sound blocking qualities. Find some wood and knock on it. Notice the dull thud? That, my friends, is why wood doors make great STC doors. They naturally deaden the sound.

Metal doors are filled with various materials, such as Rockwool, to increase the sound insulation properties.

When considering purchasing STC doors, be sure tht you don’t neglect the frames. You want to be sure that the frames are made of wood, or some sort of insulation such as spray foam or Rockwool.

If you are in the market for STC doors, let us know. We’re happy to help specify the best product for your needs.