Author Topic: Need to build a virtually soundproof room to sleep in  (Read 1656 times)


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Need to build a virtually soundproof room to sleep in
« on: August 29, 2019, 12:43:13 AM »
I am in the process of renovating a small single family home in a residential neighborhood next to a road that is generally very quiet. But every hour so... and particularly very late at night... the most obnoxiously loud motorcycles (street and dirt bikes) and race cars go flying by.  They often ride in large groups to visit a popular city lights viewing platform up the road. The noise from their highly modified exhaust systems is absolutely deafening and easily approaches 110+ DB at my front door (the road is about 20 feet away from my front door).  The neighborhood has been petitioning the city to address the problem but our city is useless so I am taking matters into my own hands. 

To exacerbate matters, I suffer from a sleeping disorder and anxiety. If I am ever waken in the middle of the night, I am incapable of going back to sleep.  So if I am woken at 1 a.m. by an obnoxious motorcyclist, I will not sleep one second for the remainder of the night.   I decided it's impractical to soundproof the entire home and the noise doesn't really bother me too much as long as I'm not trying to sleep.  So I am only going to focus on extreme soundproofing measures for one single bedroom (it is just myself and my wife in the house). 

A couple things to note - I have no budget.  I will spend $50K on a 11 x 14' room to get restful sleep if I have to but I do want the money to be spent wisely and to achieve the ultimate soundproof room.   The room is not large - about 150 SF and I really only need to make this area completely soundproof. 

I am assuming that going with grout-filled CMU brick is the best route.  With either wood siding or EIFS system on the exterior.  On the interior, I plan to paint the brick then put one layer of 5/8" drywall over the brick, one layer of green glue and then one additional layer of 5/8" drywall. 

To keep the room as sound proof as possible, I am only installing one window for egress purposes (to meet code). I plan to go with two laminated windows stacked on top of each other.  So basically two independent windows, one on top of each other with about 3" of airspace between each window.   Each of the two windows will consist of one sheet of laminated glass with a PVB interlayer between two sheets of plate glass.  I am not sure if I will go with an awning, slider or single hung window yet.  Any suggestions on the type of window would be appreciated. 

I will have two individual solid core wood doors with rubber sweep beneath to access the living room (which will not be soundproofed like my bedroom).  The doors will be separated with a 4' x 4' hallway space.  I am not sure how much noise will come through the exterior wall, into the living room and ultimately through my bedroom doors... but I figured it wouldn't hurt to put two doors on top of each other. 

The bedroom is on the second floor with a garage below.  So I will have to soundproof the floor between my bedroom and garage as well because noise will come through the garage door (garage doors are lousy for sound insulation).  I am assuming I can simply pour concrete onto a pan that sits over my floor.  This would force me to build a step up into the bedroom which I am OK with.  I am not sure if pouring concrete on the floor is overkill but I am worried that a lot of noise will come through the garage door and then the bedroom floor.  Maybe several layers of drywall in the garage plus resilient channel plus insulation may do the trick but I am not sure. 

I am not sure how to tackle the ceiling but I am thinking of using hanger plates and running 2x8" rafters (so the rafters attach to the side of the CMU wall as opposed to resting on top) and then pouring concrete into a metal pan that sits over these rafters.  The concrete will run continuously across the entire ceiling with no opening or air gaps.  I would then put drywall over the pan below.  I can also run resilient channel over the metal pan to mount the drywall. 

In order to get the level soundproofing I need for the space, I am basically building a bomb shelter.  But I want to make sure what I ultimately build is more of a quiet shelter vs a bomb shelter. 

Does the above build scenario sound like I will be able to completely isolate myself from the noise outside?  The goal is to take the loudest bike you ever heard into a faint whisper inside the room.  I know that sounds impossible but I will do my best to get there.  Again, I am only looking to sound proof an area about 11 x 14'.  Not a huge space. 

I am assuming mass is more critical based on the type of noise I am trying to isolate.  But I am open to building a thicker wall with air space if that is a better way to go.  Any feedback is much appreciated and thank you in advance for any responses!

Randy S

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Re: Need to build a virtually soundproof room to sleep in
« Reply #1 on: August 29, 2019, 07:24:38 PM »
I appreciate the thorough post but what has stopped me from a lengthy reply is that you mention this room is on a second floor!
I do not think a standard stick built structure was engineered to hold this amount of added weight.
Once my designs exceed 25lbs sqft I have to go back and consult with structural engineers to insure I can support this type of design. Using filled 8" cinder block will exceed this weight by far.

Since you seem adamant about a successful soundproof room I feel it would be best to have a discussion over the phone.

Please contact me direct at your convenience and we can discuss your approach and I can share my many years of experience with these type of rooms.

Randy S.


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Re: Need to build a virtually soundproof room to sleep in
« Reply #2 on: August 31, 2019, 01:45:30 AM »
Thanks, Randy.  I will try you by phone next week.  I apologize but you are correct... while the bedroom is on the second floor, the CMU is being built from the ground up.  So directly below my room will be a storage room (identical in size to my bedroom) surrounded by CMU.  So technically the sound won't make it from the garage and to the floor of the room.  So unless I'm missing something, the focus would be just on the walls, doors, windows and ceiling.  Thank you!