A noisy environment can have detrimental effects on your quality of life. Especially when it invades the place where you’re supposed to relax the most – your home. We’re going to classify noise as any unwanted sound. Your teenager blasting music from his new record player is noise (yes they’re making a comeback). The construction sound from outside – noise. The T.V. in the other room – noise. Luckily, this article will help you do something about it!
While the most effective soundproofing is completed during the construction stage, there are still a few tweaks we can make to existing rooms to lessen the sound transmission.
Let’s first cover how sound transmission is measured and then move onto some actionable tips you can use to cut down on the noise.
Sound Transmission Class (STC)
Sound Transmission Class, or STC, is the universal way to measure the amount of sound that is transferred from one room to the next. The STC is a numerical value given to different floors, walls, ceilings, insulation, doors, etc. as a way to quantify the level of sound transmission.
In short, the STC provides a rough idea of how much sound a door, for example, might stop. The higher the STC the less sound will be transmitted.
Untreated rooms with typically have an STC of around 15. With a few quick additions to the room, we can hopefully increase the STC above 25.
How Sound is Transmitted
Understanding the basics of sound transmission will go a long way in helping us soundproof our rooms. Unfortunately, conventional walls and ceilings are only marginally effective when it comes to blocking noise.
Sound waves strike one surface and transfer through the air gap to the other surface where they’re broadcast as noise. Additionally, any solid connection, say between the stud and drywall, will act as a direct transmission path for the sound waves.
When it comes to soundproofing there are two main things you need to focus on: sealing any air leaks and improving the acoustic damping on all sides of the room where sound transmission is possible.
Soundproofing Without Renovating
If you want a completely soundproof room you’re going to need to do a major renovation. Unfortunately, this is both time-consuming and expensive. So what are the options for the rest of us?
While not perfect, there are a few things you can do to improve the STC of your room.
- Seal Any Gaps With Acoustic Sealant.
One of our main tools is going to be acoustic sealant. A special type of caulking, it’s perfect for sealing up any air leaks where sound can flow freely.
First, remove the baseboard trim and seal off the space between the drywall and floor. Next, find any electrical boxes and seal the gap between the box and the wall. Finally, completely fill the holes in the box.
If you have any recessed lighting fill these in as well. Any plumbing lines should also be sealed. Finishing elements, such as plates and molding, should be installed after the sealant is applied.
A quick note: You’re going to have a very hard time increasing your STC if there is duct entering your room from a central air system. These ducts leak sound like crazy and there are no easy fixes that I am aware of.
Doors are usually the biggest problem areas. Untreated, hollow body doors will usually have an STC rating of 15 or less. If possible, upgrading to a solid core wood door will have a very positive impact on your rooms STC.
Whichever door you have you’ll want to fill any space between the jamb and the adjacent doorframe with your acoustic sealant. Next, you’ll want to add some weather stripping to the doorstop molding. This creates a tight seal around most of the door perimeter.
Finally, by installing a sweep and a transition strip at the bottom of the door you’ll have an airtight seal. With hollow wood panel doors, you’ll be able to increase the STC above 20 using this method.
- Sound Absorbing Material
Hardwood, tile, or laminates are notoriously bad for sound transmission. By increasing the damping within the room using sound absorbing material/objects the STC rating will increase.
Your first option is to purchase sound-absorbing curtains. These are dense, specially designed curtains to absorb sound transmission coming from outside your room. However, they will also cut down on any reverberations inside the room.
Your next option would be installing carpeting in the room. Similarly, while this is also the preferred way to decrease the noise transfer through the floor to the basement, it will also reduce the reverberations within the room itself.
If you have one trouble wall, in particular, hang a thick blanket or mount a bookshelf directly to the wall. Anything to make that particular wall thicker will go a long way in increasing your STC.
If you require more soundproof you’ll have to go with more drastic measures. These may involve installing a new wall, adding damping to your studs, using soundproof insulation, installing sound barriers, or using thick drywall.
While not perfect, these small fixes should hopefully make a dent in your STC and provide you with a little more peace and quiet. Each room will need to be tackled on a case-by-case basis. By keeping in mind the principles and tips above you will be well on your way to a relaxing soundproof home.
About Author – Glen Parry writes for the blog Audio Mastered. He’s been involved in many soundproofing projects as well as home studio construction. You can find more information on acoustic treatment or other gear related guides such as the top digital pianos over at audiomastered.com.