Home soundproofing

I'm looking for the home interior equivalent of the "Peel & Seal" vs Dynomat.

We're doing some remodeling in one of the rooms here at home. I need to replace the drywall and was thinking this would be a good time to add some soundproofing/deadening before the new walls go up.

Other than adding some R13 are their any Grassroots suggestions? We are not reframing the room so going to 6" walls with offset studs isn't going to happen.

I did come across something that looked like Dynomat and you would wrap the studs with it. Not sure if that was legit or snake oil.

Also came across some rubbery stuff that would go between the drywall and framing that seems to be very similar to the GAF Tri Ply 4 in the roofing section of the Depot.

So I'm up for any recommendations.

Thanks, Rob

Spray foam the walls.

Hey Rob!

My brother used to build furniture in his house. In his "shop" area, he replaced (or covered?) the drywall with "Homasote." Worked really well for keeping noise in. I would assume it'd do pretty well at keeping noise out too.

I've used a lot of Homosote for sound deadening. I wouldn't use it for a finished wall (it's basically compressed newspaper- very soft, would ding easily, and extremely absorbent, so it would wick up dampness from just about anything).

Is there a reason you don't want to use R-13? It would help an awful lot. If not, can you increase the density of the wall some other way? (stack bricks, sheetrock scraps, plaster scraps, etc?)

There are two main characteristics to reducing sound transmission- increasing density and mass, and de-coupling the components to break the vibration paths.

That means, try to get the wall surface panel (sheetrock) on one side of the wall physically disconnected from the other. So, yes, staggered studs would help. They don't have to be 6". They could be 2x3's (if not load bearing). Or resilient metal channels ("hat" channel) run horizontally.

If you can't re-frame, you can get some separation by padding one side of the studs with strips of padding (homosote would be great, but thick cardboard might work too). Use continuous beads of construction adhesive (Liquid Nails) on the studs, and screw your sheetrock using minimal screws. I've built some walls where we actually removed the screws after the glue dried, so the screws wouldn't transmit the sound.

Different frequencies are transmitted through different materials. Most of the sounddeadening walls I've built use multiple types of density materials to reduce the transmission of different frequencies (after de-coupling the framing, and adding density with insulation). So, 1/2" sheetrock will keep out different sounds than 5/8", or 1/4". I've built walls that had 1/2" on one side, than a double layer on the other side (5/8" and 1/4").

I'm not an acoustical engineer, but I've worked for several.

What about cementboard?

I used Roxul "Safe 'n Sound insulation - worked great.

http://www.roxul.com/

Y'wanna talk grassroots? Back when I had a shop, we got deliveries most every day, cushioned in bubble wrap. Rather than throw it away, I started stuffing the wrap into garbage bags. After 9 years, I had enough bags to fill a derelict van in my backyard.

About that time, I was remodeling my bathroom. I decided to insulate the walls and tub, but rather than go and buy the pink stuff, I figured what the heck, and stapled bubble wrap between the studs, and stuffed the old steel tub full of bubbles, then covered the walls with cedar shakes and faux brick paneling (outhouse theme).

Once I had it put together, I noticed that it was nearly soundproof, and is now the most insulated room in my home. You can fill the tub with hot water, and come back 5 hours later, and the water is still warm. My girlfriend likes to sing in the shower, and even though I'm in the next room, I can't tell what song she's singing (usually Billy Joe Royal or George Strait).

I'm not saying you should go buy a bunch of bubble wrap to insulate your room (that stuff ain't cheap, unless you get it gratis), but it worked for me; the bathroom is like a recording studio now....

Which reminds me.. I've heard stories of cardboard egg crates.........

Wow, that was some fast responding! Thanks guys!

SVreX, I'm not opposed to the R-13 just didn't know if it would make a difference or not. If it does I'll go for it. If it doesn't I was hoping somebody out here would say don't waste your time.

This is going to be a finished room, so Homosote on the outer layer isn't going to work. but the layer of Homosote or thick cardboard on the studs could work.

This project has already snowballed pretty far. Reframing would probably find me getting bricked up on the other side of the wall.

It started with new furniture for the home office --> should fix the drywall from where the old A/C unit failed and flooded the wall with condensation --> Replacing wall is easier than fixing all the damaged areas --> should put a ceiling fan in and center it in the room --> run new wiring for said fan and light --> paint is peeling off other walls from poor paint choices of previous owners for 45 years might as well redo the other walls --> should put in sound deadening so when I have the tunes going back here is doesn't disturb the Mrs. watching a movie in the other room.

I'm not looking to make this a studio, just want to try and tone down some of the noise from out front (we're on a busy road) and keep the noise in this room contained reasonably well. If we're successful with quieting down this room the other rooms will get the same or better treatment.

-Rob

In reply to Rob_Mopar:

I am just finishing up a basement apartment conversion that I put a great deal of design intent and experimentation into sound deadening.

Right off the bat, the R13 will help quite a bit and is an essential starting point.

I tried this stuff to decouple the drywall from the studs: http://www.soundaway.com/Sound_Isolation_Tape_p/13101.htm

It made taping and muddling much more difficult because the drywall floats on the foam. so I did not use it after the initial try. It does cut a half a db or something.

I did find benefit in buying cheap ass silicone sealant and putting a fat bead down on the studs before screwing the drywall on and then squirting said cheapass silicone along every seam between the studs and the drywall on the side I could get to before it was covered. It served to dampen the drywall a fair amount. I could hear the differance when I rapped it with my knuckles.

I insulated the ceiling with R30. That kicked ass.

Filling all the holes at the floor and ceiling you can get to with expanding foam will help.

Of course, once you do what ever you are going to do to the room, you can eat lots of sound with padding under carpet, padding under area rugs, heavy curtains and decoupling speakers from the floor or the walls.

I have also killed sound in rooms by adding extruded sheets of crap foam into the hollow area created by the frames of paintings and prints. It all adds up.

When we built our house we had EVERY interior wall insulated with the pink stuff. R13 I think. Couldnt be happier. I likes me a quiet house.

I also think it helps with energy bills, not using that room? Close the vent and shut the door. Didnt cost a thing as the builder threw it in gratis.

Cool, thanks guys. Now I have some directions to look in.

Eastpark, looks like there's a Roxul dealer about 45 minutes from here. I'll give them a call tomorrow to see if they actually stock it and what it runs.

Shaun & Porksboy, if the Roxul doesn't pan out I'll be picking up the R13.

The silicone idea is interesting. I was already planning on the Liquid Nails so that's not too different from the silicone idea.

Tommy, the room is 10' x 12'. That would be a bunch of cement board. I think finishing it might be tough. Might feel like a prison cell with all that concrete.

NYG95GA, I don't have anywhere near that much bubble wrap around the house. Interesting bathroom concept too.

John, I thought about spray foam. That's a lot of spray foam. And eventually I'll be replacing the drywall on the hall and foyer sides. Peeling the drywall off with the foam holding it on might be tough.

Poopshovel, I'll keep the Homosote in mind for the closet area around my air compressor. That might help kill some of that noise too.

I'll post some updates as I make progress.

-Rob

Don't overlook the trash.

We used to fill a dumpster with the drywall scraps from a new house, until we realized it made pretty good density filler. Cut it into pieces and stack between the studs.

We do it intentionally in areas (like bathrooms) that require reduced sound transmission. Saves on dump fees, too.

blown in insulation works great as well. all my bathrooms are insulated

Rob_Mopar wrote: John, I thought about spray foam. That's a lot of spray foam. And eventually I'll be replacing the drywall on the hall and foyer sides. Peeling the drywall off with the foam holding it on might be tough.

They have really neat "house kits" that are two part injector kits. If the wall(s) were still open you would tack a liner (trash bags etc) to the wall you knew would be coming off and make it non sticky.

Spray foam is overkill, and very expensive.

I've been studying this a lot recenty, as I'm planning a small recording studio build within the next year or so. Here's an overview of what I've learned so far, as applicable to your situation:

Adding mass, increasing insulation, decoupling the walls, and sealing any air leaks/gaps will go a long way. But regardless of what you do, if you don't treat the entire area, you'll make minimal improvement at best - in other words, if you have a window, or hollow-core door, start there before going crazy anywhere else.

Adding a second layer of drywall onto your walls is relatvely cheap & effective for decreasing noise.

Egg crates & bubble wrap aren't as effective as actual building materials & tend to be much more flamable.

If you need to add insulaton anyway, look for "rock wool" rigid-fiberglass.

www.homerecording.com has some good info in their Studio Building forum, or I have some links I can forward to you as well.

You've gotten lots of good advice above. I just wanted to add one thing that I don't think was covered.

In general (maybe oversimplifying a bit) fiberglass insulation will help mid and high frequency isolation, but won't do much to stop low frequency sound. Decoupling or adding lots of mass (more drywall, sand in the walls, etc.) is going to work much better for stopping low frequency.

-Brian

Ball gag. No one will hear now.

Standard stud walls- sound transmission class (STC) about 33.
Add batt insulation will increase it to about STC 36-39 Double the sheetrock on both sides will increase it to about STC 38-39 Double the sheetrock AND add the insulation will get you up to about STC 41-45

Structural decoupling alone would get you over STC 60. That's about 80% quieter, and also includes excellent reductions in low frequency transmissions (which won't happen in the other methods).

It would be really nice if you could re-frame to decouple.

For new sheetrock or doubling the layers, consider a product like QuietRock.

don't even think about using packing foam that is 'contaminated' with the starch-based packing peanuts. Roaches love them.

Decoupling = two seperate stud walls?

There are multiple ways to decouple a room from an outside sound source. Floating floors, when properly engineered work well when coupled with decoupled walls and a properly designed ceiling.

The ideal wall, would be two stud walls(with as large an air gap between as you have space for), only drywalled on one side each, and both insulated.

Adding drywall to both sides of each wall in a double-wall room actually reduces effectiveness. Although, you can double-drywall one_side on either or both walls to improve noise reduction.

Keep in mind that sound will also travel through ductwork, plumbing, and even along wiring/conduit to a certain extent. That's why it's crucial to take a systematic approach if you want to make significant improvements in sound transmission reduction.

DILYSI Dave wrote: Decoupling = two seperate stud walls?

Coupling= mechanically linked together. Standard wall surfaces (drywall) are directly tied to each other (coupled) by the wood studs, which are excellent transmitters, especially of low frequencies.

Yes, 2 separate walls is one (the best) solution.

Never actually used this, but we had some samples of this stuff at my old office. Seemed like it would be pretty effective.

http://www.quietsolution.com/html/quietrock.html

I soundproofed the office of my boss once-upon-a-time. He was worried about people being able to overhear private conversations. So I had the interior of the walls strapped with lathe, stapled 1/16' lead sheet on the lathe, and put more drywall over that. It's very quiet and is the room of choice in case of nuclear attack!!