As we build our new office, the topic of how to soundproof a door has come up a few times.

While we don’t have top-secret conversations behind closed doors, there are some discussions that need to remain confidential.

As a result, we have asked:

“What are inexpensive ways to soundproof a door?”

What’s in a Rating?

ASTM International has developed sound transmission class (STC) ratings that classify how much sound is able to transfer through specific building materials.

All doors have a STC rating; the lower the rating, the more sound that will pass through the door.

We assemble doors used in government applications where the required STC ratings are 50 and higher. Top secret conversations can be held behind these doors without fear that conversations can be overheard.

However, for general office use, a rating anywhere from 30-49 is more than sufficient.

There are numerous ways to achieve higher STC ratings.

The Inexpensive Ways to Soundproof a Door

Door Material

If you can start from scratch, the best thing you can do to soundproof a door is specify a solid core wood door. These doors have phenomenal insulation properties that will block a decent amount of sound.

VT Industries and Graham Wood Doors have affordable acoustic doors with STC ratings from 29 through 49.

Overly Door Company specializes in acoustical doors and is a leader in the market for specialized doors. They manufacture both metal and wood doors with STC ratings up to 57. In 2010, they were featured on Modern Marvels for their bullet proof and blast proof doors.

Frame Material

If you have to soundproof a door that is already installed, don’t worry; there are still things you can do. First, check out your frame material. If the frame is made of wood, your door already has some soundproof qualities.

If, however, you have a hollow metal frame, you can backfill the frame with insulation such as spray foam or Rockwool.

Sound Seals and Door Bottoms

Next you can install sound seals and door bottoms. These products reduce the amount of sound that can transfer through the gap between the door and frame or the door and threshold.

You can go as cheap as silicone peel and stick gaskets, or you can purchase products specifically made to soundproof a door. PEMKO, a division of ASSA ABLOY, has developed a comprehensive line of seals and door bottoms that will increase the STC rating of your doors.

If you follow these simple steps, you can take your door from this:

 

To this:

Do you need more information on how to soundproof a door? Let us know, we’re happy to answer any questions you may have!