Spray foam for sound deadening?

[MuleShack]

We are starting to gather some information about finishing our basement such as how much the materials are going to cost and for the things we are not prepared to do, get estimates etc.

I'm wondering about insulation in both the walls and the ceiling. When the house was build they put fiberglass in the walls so That part is done, but I think I need to tear it up to get the wiring all done.

To the point, I want to try to keep the basement somewhat sound proof so I can turn up the Xbox or the TV and not have to hear the dreaded "Can you turn it down a little" So I was thinking that spray foam would probably be a better sound deadening material to spray in the floor beams and then leave the fiberglass in the walls.

Of course the other option is to take the fiberglass out of the walls and stick it in the floor beams of the ceiling and then have the outside walls sprayed.

Which of these two options would make more sense?

[LightningBG]

Spray foam can get expensive.

[BoxMN]

Contractor friend said he always puts insulation (he uses glass I think) in the ceiling above the basement for sound deadening. As for insulation in general in basement, there are many ways to do it right and WRONG so try to get as good of advice from those who know as you can - mainly regarding vapor barrier do's and dont's. In our new construction contractor put foiled thermex (sp?) on block walls (no plastic) and glass batt in studded area with poly over it, and taped. Ceiling is still unfinished, so I will watch advice you get for when I do it.

edit - oh yeah, we sprayed the risor, or whatever the outside of the joists is called, above the block or top caps (I am not contractor, can you tell, haha!)

[IamZombie]

I saw some stuff on HGTV called Resilient channel for sound deadening.

http://www.jm.com/insulation/faqs/996.htm

[Mike_Top]

I'm a building science consultant and I've spent a few years studying up on insulation and vapor barriers. New construction builders commonly use 1.5" thick Thermax rigid foam board on the interior basement walls, and spray foam the rim joist to R-19. Spray foaming the walls or ceiling is NOT the way to go due to its high cost, unless you are crazy about energy efficiency (spray foam in the ceiling won't provide any energy saving anyways). I'd say don't put spray foam in the basement ceiling - fiberglass will accomplish sound-dampening at a much cheaper cost. You could put either R-19 or R-30 fiberglass batts in the ceiling...R-30 could work if the floor joists are 2x10's or bigger, and would probably insulate sound better. If you're going to insulate the foundation walls, put R-10 thermax foam on the interior walls. This gives you the code-required fire resistant barrier, a vapor barrier, and can be covered with drywall.

The resilient channels may provide sound-dampening, but they will reduce the effectiveness of the insulation because of the airspace. fiberglass batts are most effective at slowing down heat loss when they fill the whole cavity.

Give me a email if you've got questions

[email protected]

[cavalierowner]

As far as isolating sound, I suggest adding the resilient channels to the joists and then srewing the gypsum board to the channels. That will do far more than just adding insulation in the joist space. Here is a link to National Gypsum's tested assemblies http://www.nationalgypsum.com/File/golds.pdf. The column STC (Sound Transmision Class) is the resistance to sound transfer; higher is better. A standard framed system without channels or insulation is STC 37; add resilient channels and the STC jumps to 45, STC 50 if you add sound insulation in addition to tjhe channels. The other part of the equation is transfer thru openings like ducts, doors, etc. You can help out doors a lot by weatherstripping them and caulking around electrical boxes or ceiling registers. Believe me, isolating sound is very difficult.

[MuleShack]

Thanks for the feed back so far. I was unsure if the spray foam would be more sound proof than anything else. Apparently the resilient channels are the thing to do. This might be a better option for the ceiling anyway being there is so much junk running thru the joists. I can still stuff the openings with fiberglass and use some spray foam from the can to fill up holes and cracks. Then I can frame around the duct work and still tuck some fiberflass inside the framing and then use the channels outside the framing with a slice of foam between the channels. The duct work is going to be a big part of the sound transfer down in the basement. I have 4 trunk runs going the length of the basement, so protecting them is going to be the big obstacle.

I'm not looking for a sound studio, just something to keep the noice from traveling upstairs thru the walls and ceiling.

[IamZombie]

This is the other stuff I've seen them use on shows like Holmes Inspection and Holmes on Homes.

http://www.roxul.com/residential/create+a+quiet+home+with+safe%E2%80%99n%E2%80%99sound

[Transporter]

I found spray foam to be a very ineffective sound proofing material. We used it in the construction of engine hatch covers inside a boat thinking it has to sound proof, wrong. It deadened nothing, granted two large diesels make a lot of noise, but it did nothing. I had some rolls of sound insulating lead that I ended up sandwiching inside the hatches and it worked like a charm, but I wouldn't want it in my house. I just replaced the flooring inside another boat that has even bigger diesels and used a material called mass loaded vinyl, put it on top of the aluminum deck before the floor went on and it reduced the noise by over 50% and no lead. There are a few good soundproofing places down in the cities, they are a great help, houses are easy compared to metal boats.

[soldoncass]

With sound deadening everything is cumalitive....or in other words, anything helps. The more you do, the more it will help. We did a room in the basement of a house once for a kids "drum practice room". We fiberglassed the ceiling joists, then a 1/2 inch sound board(like a bulletin board stuff), then the channels... to screw the rock to. It was quite effective, but nothing stops it completely. The main thing to remember is to separate components, so sound can't transfer straight through. The other thing is that you don't want the sound to ECHO off walls, ceilings, floors. Accoustical ceilings, carpets, "soft" wall coverings, anything that will break-up an echo, will make a big difference. Think like a stealth bomber....soft skin, odd angles, etc. Making turns to get into the room, with sound- absorbing material on the turns help keep the sound from blasting staight into other areas, also. Good luck.

[LightningBG]

This is kinda going to the exxtreme, but an interesting read.

Quote:

How To Build A "Room-Within-A-Room"

Get the ultimate in sound-proofing by borrowing this idea used in professional recording studios.

One of the most effective ways to control the leakage of sound is to build a room within a room. Forcing the sound waves to have to travel through a double-wall, or a double-floor weakens it considerably. This also has the double effect of isolating the movie-goers within the room from sounds coming in from the outside.

room within a room top-down viewLets say you have an existing room in your basement thats already framed and drywalled. To build your room within a room, you'd have to construct four new walls, a new ceiling, and a new floor. There has to be absolutely no contact between the inner and outside walls and ceiling. The whole thing would then have to "float" above the existing cement floor on special rubber footings.

You would start by building a floor using similar techniques used to frame a wall. To reduce the amount of wasted space, the width and length of the new floor should be about 6 inches less than the width and length of the room it will be in. This will provide enough of a gap between the rooms to reduce the transmission of sound.

Instead of using drywall, you would use 3/4" plywood on the bottom of the new floor. You'd then fill the gaps between the studs with fiberglass insulation. You can also use special insulation products such as Owens Corning QuietZone and Roxul's Safe'n Sound which provide both fire resistance and sound deadening. Be sure to use a breathing mask and gloves when handling any fiberglass insulation product. Before finishing the floor with 3/4" plywood, mark off the location of each stud. These marks will help you easily find the studs later when you have to screw the walls to them.

room within a room floor cutout

Build the new floor on 1/4" to 1/2" thick rubber isolation mats. These mats are designed to virtually eliminate the transmission of sound vibrations. They're usually a specialty item but can easily be purchased online.

Now that our room within a room has its new floor, its time to build the walls. You will frame each wall and hang drywall on the side that will be facing the gap. Raise each wall into position and screw them into the floor's studs using the markings you made earlier.

Regular ceilings in a house are built using ceiling joists. These are wooden members that span the width of a room and hold up the ceiling, roof, or floor of a house. In our case, we can get away with using 2x4's for our ceiling joists since we don't need to hold up anything other than the ceiling's drywall and some light fixtures. Its pretty hard to frame a completed ceiling and lift it into place so you'll have to build it piece by piece.

A wall has both a top plate and a bottom plate. Ceilings on the other hand have header joists to which the 2x4's are connected. Install a pair of header joists on two walls that oppose each other. Starting at one end of the room, screw a series of 2x4's between the header joists 16 inches on center.

When each wall and ceiling are framed and installed, its time to lay out your electrical wiring. Though this site is for the do-it-yourselfer, I recommend you hire a professional electrician for this part of the project. With the electrical wiring completed and inspected, its time to install more sound insulating fiberglass insulation between the wall studs and in the ceiling.

You'll then finish the job by filling in the empty space between the exposed studs in the walls and ceiling with more fiberglass insulation. When done, you'd hang the rest of the drywall on the inside walls of your new room. You can rent a panel lift or use a T-brace to help lift the drywall to the ceiling. You can use a solid wood or steel door and you can install weather stripping to seal off any cracks.

[CAMAN]

I found spray foam to be a very ineffective sound proofing material. We used it in the construction of engine hatch covers inside a boat thinking it has to sound proof, wrong. It deadened nothing, granted two large diesels make a lot of noise, but it did nothing. I had some rolls of sound insulating lead that I ended up sandwiching inside the hatches and it worked like a charm, but I wouldn't want it in my house. I just replaced the flooring inside another boat that has even bigger diesels and used a material called mass loaded vinyl, put it on top of the aluminum deck before the floor went on and it reduced the noise by over 50% and no lead. There are a few good soundproofing places down in the cities, they are a great help, houses are easy compared to metal boats.

They have two different types of spray foam. Open cell foam is used for soundproofing, closed cell is used for insulation. But you NEVER want to put open cell in a boat, it acts like a sponge.

[Eiger0304]

How true this is I'm not sure. A couple years back a guy told me he put felt strips up on his 2x4 frame walls, before he put sheet-rock up. He said it reduced sound because, sound travels better through solid objects. He said he did this throughout his upstairs, when he built his house. He said it made a huge difference in bathroom and laundry room. I do not know if he put batting in the walls or not. Do not know what kind of felt strips or how thick they were.

[LightningBG]

How true this is I'm not sure. A couple years back a guy told me he put felt strips up on his 2x4 frame walls, before he put sheet-rock up. He said it reduced sound because, sound travels better through solid objects. He said he did this throughout his upstairs, when he built his house. He said it made a huge difference in bathroom and laundry room. I do not know if he put batting in the walls or not. Do not know what kind of felt strips or how thick they were.

I could see that helping somewhat. Anything to cushion solid surfaces from each other will help to a degree. How much? Tough to say.

Its kinda like some people put a rubber piece where their garage door opener connects to the ceiling of the garage. Helps reduce the vibration and therefore sound that transmits to other parts of the house.