This garage is being remodeled into a practice room for musical instruments! Let’s take a walk through…
“Hi There!”, Robby, one of the “Super Soundproofing” company consultants greets you as you enter the garage.
“Soundproofing a garage is one of the most difficult rooms to do because it’s usually partially unfinished, meaning the walls are thin and the movable garage door is a particular problem because it passes sound so readily”. He says as you walk with him into the garage.
“This can be a blessing, in that we can make major changes to the interior without ripping out walls and so on. We are building a “room-within-a-room” here, with studding separate from the existing studding. Since we need to keep the primary use as a garage, (as required by most building codes), the big door must remain operable. We will do everything we can to soundproof this garage because we don’t want any complaints from the neighbors at all. Even so, knowing we will not be able to make it absolutely soundproof, we’ll limit musical instrument playing to late morning , stopping before evening. We will also casually contact each of our neighbors and explain we are doing this remodeling to try to prevent annoying them”. He tells you.
“Our garage is fairly typical, a two car unit with bare wall studding and rafters. Even the walls to the house, (two of them), are unfinished on our side. Because we want to also be able to watch TV inside the home, we’ll pay extra attention to attenuating sound toward the house as well. The procedures shown here can be applied to most any room, even a shed”.
“We need to keep expense as low as we can, so we’ll do the work ourselves but because the sound of a band is so loud and overwhelming, using common building materials won’t perform as well as materials designed for sound control, so we’ll use professional materials. The first place we start is with the walls, carefully caulking any cracks or crevices in them to stop sound and air infiltration. We use a special soundproofing caulk that will stay flexible forever. Then we place “Wonderboard” or “Duroc” concrete board between the studs with construction adhesive bonding them to the inside of the drywall sheeting. A few nails hold them in position, as you can see here. We also caulk them along the edges. They will provide the mass we need to help stop those low bass notes from passing through. The next step with the walls is to rent a staple gun and staple Mass Loaded Vinyl (MLV) to the studding. You could run it horizontally, but we prefer to hang it vertically like wallpaper. It’s 4′ width allows it to be attached to the studding that’s on 2′ centers nicely. If it was hung horizontally, there may be gaps between unsupported runs that could let sound slip through and so we want a real tight fit”.
Next we’ll frame out a new set of “false” walls spaced about 6″ away from our roofing covered walls, using 2X4’s. This space between the walls must be airtight. Some have asked if the airspace should be filled with fiberglass batting. While it makes a good thermal insulator, it doesn’t have much sound absorbing qualities. A better material is absorbent cotton batting.
The doorway to the house we’ve framed into our wall, leaving the existing door opening toward the house in place and adding a second door that opens inward toward the garage. The new door is an exterior door with a solid core. (More on this!) Each door has a covering of “Super Soundproofing Mat” applied to their surfaces with contact cement. We used 1/2″ thickness here.
Let’s go to lunch and when we get back, the new walls will have been framed out. I’ll show you how the guys here framed the new walls”.
“Sure”, you reply. While you’re at lunch, you ask him a nagging question: “Say, Robby, what about that garage door. Isn’t it going to be a difficult job to soundproof”?
Yes, it is a problem area, but there are a few things one can do to start with. One, get an insulated door and Two, do not get one with windows! Also a folding door is harder to deal with than a tilt-up”
“What if there were some windows to deal with? Explain please”.
When you and he return from lunch, he points out the features of the studding job the workmen have done: “The men have laid a sill for the false wall on sections of our “Super Soundproofing Vibration Pads“. Here, have a look at one.
You take one in your hand and examine it. “It looks like ribbed neoprene”. you comment.
“Yes, it is a special ribbed neoprene. They come in 2″ square and about 3/8″ thick. We used to use a rubber strip, but the rubber, over time, compressed and the vibration isolation was lost. These pads will not do that”.
“I see they are placed every one and a half to two feet or so”.
“Yes, they can be spaced out a longer distance to support the wall, but we intend to use two layers of drywall, which adds considerable weight. Anyway they are cheap and very effective in providing a isolating base for our “soundwall” of double drywall, actually a layer of Sound Deadening Board covered with sheetrock. A heavy layer of acoustical caulk is laid down to cement the sill to the floor. If the gap is too wide, use some “Backer Square” to fill the gap first.
The drywall is 5/8″ “Firecode” gypsum board, mounted on “Hangers” (sound clips) or “resilient channels” to provide isolation. A thin layer of “1/8″ Super Soundproofing Mat” is applied in the airspace on one of the layers of drywall facing the dead air space, providing additional sound absorption. Twod be better to add natural cotton batting to reduce standing waves between bare studs. The outer layer of sheetrock is brought within a 1/4″ up to the ceiling and 1/4″ from the floor. Caulking then seals the gap. The corners are also sealed in the same fashion. Taping finishes the job, ready for paint, if desired.”
The framing clearly showed the 6″ distance from the inner walls covered with “Sound Deadening board” and extended up to but not touching the rafters.
“What about the ceiling? You ask.
“We’re installing non-flush fluorescent tube lights to avoid cutting holes and covered the ceiling with resilient channel and sheetrock. We’ve already put “soundboard” sheets on top of the rafters for support and laid several complete layers of more MLV over the soundboard up inside the attic area, tightly butted and sealed together. This gives us an airspace the depth of the 6″ rafters between the plywood and the drywall on hangers, same as the walls. A foot would be better, but we need the space! If we find there is some sound emission from the attic, we can lay more roofing or perhaps attach it to the attic roof rafters. Depending on the final testing, we may need more “Super Soundproofing” barrier material (MLV) called “Flooring” in there too.”
“I still want to see what you did to the garage door to stop sound from passing through it!”
“Remember, we can’t completely “soundproof” anything. Everything has some attainable level of noise reduction, depending on time and expense and perhaps practical considerations. But we can get the noise reduction down to some level of tolerance, using these techniques, depending on the individual whose hearing the noise!
You’ll notice our door is of the insulated variety, meaning that the manufacturer has made some effort to insulate it. This is for thermal properties, but it’s somewhat effective for reducing sound transmission. Since it has no windows, we don’t have to deal with that.
What we’ve done is to hang some acoustical blankets on ropes across the entire door. These are 4’X10″ and about 2″ thick. We’ve used these for portable sound booths, too. When the door is down, we can pull the curtain over it and cover the door. Then we unfold these 4″X8″ panels made of 5/8″ exterior plywood on gate hinges, bolted, not screwed. The two panels on each side cover our 16′ door. They fold nicely back out of the way in the 4′ space from the door to the wall. We’ve added some office chair “Ball rollers” to the bottoms to help in extending them out to cover the door”.
“Hmmm”, you muse, “looks like they are covered with soundproofing mat”.
“Yes, we covered each side with “1/2” “Super Soundproofing Mat” attached with contact cement”.
“What about ventilation? You’ve created a very tightly controlled airspace here.”
“We have a window style air conditioner mounted in the attic with a duct into the room. It’s electrical controls are mounted down here. The duct is an “S” shape to reduce noise from going out. It can recycle, exhaust or bring in fresh air as needed. The duct is coated with “Super Soundproofing Liquid” to reduce reverberation in the duct and covered with more of the mat.”
“I’m concerned that for my trio and my vocalist, we’ll get some unwanted sound reflections from the walls”.
“That’s another subject, but you can probably easily fix that with an application of thin soundproofing mat or even foam sound conditioning panels such as pyramids or wedgies to the walls”.
“After all this, and what if the neighbors still complain?”
“We’ll take our Radio Shack sound-level meter ($35) and make some measurements to try to measure the overall noise level at some fixed places away from the garage while the band is playing. (A car horn and a 12 volt battery will also work well as a sound source). If we discover a “leak”, that is a place where the level is noticeably higher than the other areas, we’ll pinpoint it and plug it!”
“Well, seems like once they start complaining there’s not much you can do to satisfy them!”
“Very true, that’s why it’s important to do all you can to prevent that first complaint! Some movable, insulated panels surrounding the loudest instruments may be needed to cut down the sound level at that point even more.”
Interested, pointing, you ask: “Is that what those are?”
Yes, to make them, simply take a 4’X8′ sheet of soundboard and cut it into two 4′ sections. Hinge them together (they will be easier to store that way), and cover them with soundproofing mat. Laid on their sides, they form a wide “V” on it’s side. This tends to help block the loudest musical instruments near the source”.