Child’s Bedroom Soundproofing

N.M. Writes:

We built an addition to our home and our master bedroom shares a wall with our youngest son’s bedroom. Unfortunately, any noise in our room is heard in his room. Talking, TV (even low volume), listening to radio – it is all heard in the next room which keeps him awake (or wakes him up) and provides us with no privacy. Do you have any solutions, short of ripping out the wall and replacing it, to put on the wall to stop the sound?

There are a few things to consider, but fixing the problem is not an impossible task. We receive a lot of inquiries from people who, of course, want an easy and simple solution that will not create a big mess. Occasionally this is a possibility, but to get the job done correctly, some construction is almost always involved. Let’s take this one step at a time.

I would first ask you to inspect the air gaps around your son’s bedroom door. If, in fact, the sound is leaking through the perimeter of the door, sealing up the air gaps around the door is going to be not only one of the more cost affective first steps, but also one of the most effective means to keep sound out of the room.

Sound is similar to water when getting in/out of spaces. Both water and sound are going to follow the path of least resistance. A one-percent air gap around the door can leak thirty percent of the sound from one side of the door to the other. A one-quarter inch gap at the bottom of the door will leak a very significant amount of sound into your son’s room.

This issue can be fixed by installing our door seal kits. These kits are very easy to install onto most doors. If you have carpet in the doorway, you will need to install a threshold which you can get at any home supply center. The seal will need a hard surface to seal onto. The standard kit (17/32″ wide) will cost approximately $247.00 which includes the automatic door bottom as well as the jamb seal for the sides and top of the door frame. The heavy duty kit (7/8″ thick) will cost approximately $470.00 and simply provides a better seal than the standard kit.

If the sound is coming through the wall itself, it becomes a bit more of an involved solution. I would first ask you to inspect the wall to see if there is a common return cavity for the HVAC system. This will commonly be a very weak link in the wall construction and a direct conduit for the sound. If not, I would ask you to carefully listen while standing in your son’s bedroom to try to determine if there is one particular area in the wall where the sound is making it’s way through the structure.

There are a few things that can be done, and choosing which depends on the severity of the problem, and the amount of work that you are comfortable with or willing to do.

I will start with the most effective approach – which is the RSIC-1 Sound Isolation clips. These clips are a product that is designed to “float” a new layer of drywall off of the structure. I would suggest installing the clips on the noise-source side of the wall and filling the air space between the existing wall and the “new” layer of sheet rock with our 1″ Quiet liner to deaden the airspace even more. The installation would require extending outlets and receptacles approximately 2″ toward the interior of the room, installing a new layer of drywall, taping, mudding and re-installing the trim along the floor. This is a fairly involved process, but will be the most effective if done correctly. I have had the best reports from customers who have decided to go with the RSIC-1 clips with regards to all of the other products that I offer.

Another approach is with a layer of Barrier Decoupler on the common wall – under a “new” layer of sheet rock. This product will increase the amount of density and mass between the two spaces. The more mass you introduce between a noise source and a receiver, the weaker the sound is when it gets from one side of the barrier to the other. This installation would also involve re-doing the sheet rock on one side of the room – similar to the RSIC-1 Clips, but would be less effective.

Another way to help attenuate the sound is with a layer of Green Glue, which is a liquid, waterborne, viscoelastic damping compound which represents the highest performance product of it’s type. This product is also used with another layer of sheet rock. The Green Glue is smeared on one surface in a random surface pattern. The two layers of rock are then pressed together, and the new layer of rock is crewed through the existing layer, back into the structure (studs). A simple definition of Viscoelastic is :A shock absorbing rubber-like material. The product changes the airborne wave of energy into heat energy by taking advantage of the liquid, yet elastic “maze” of “glue.” People have been very happy with the result compared to the cost.


2 Comments

  1. william boyer

    great blog, thanks! any words of wisdom on insulating for noise and temp. inside my box truck

    • Ted

      William,
      Thank you for the feedback on the blog! Automobile applications can be a bit trickier than residential because of the number and location of the variables that come into play. Are you able to treat the engine bay or the engine side of the firewall?

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