Sound proofing

[Ben Abate]

Hello all,

I have a question for you, I am in the process of remodeling my lower level. I would like to find a way to stop the transfer of sound of people walking on the floors above. Our kitchen for instance is above the room that I am working on. The kitchen has maple hardwood floors. The transfer of the sound of my wife walking upstairs makes it not as quiet as I would like it. She only weighs 100 lbs. ( I know you guys were going to say put her on a diet.) Do you see what I mean about the sound transfer. I don't believe regular bat insulation is a choice, I was thinking of using Homeisote (sp) I thought I remember reading somewhere that this is good for absorbing sound. Do any of you think that holding it down about an inch from the floor above would give a better sound value. By not being attached to the above floor it may absorb the sound with out transfer.

Any thoughts are welcomed.

thanks
Ben

[Dave Carey]

Ben,
I suggest you check some of the sites dedicated to home theaters. I know there's one system that involves basically a doubled walled ceiling but all that is way beyond my expertise. I figure if it stops sound from a basement theater moving up through the house it ought to work in the other direction as well.

[Jim Becker]

You need to do multiple things to abate the sound transfer. Fiberglass insulation will help with some frequencies and general noise, but isolation is also important. Same goes for homasote. There is a metal channel you can buy to put up that physically isolates your ceiling from the joists, for example. It's sometimes used between two layers of drywall...the layer of air provides additional isolation.

[Joe Pelonio]

I remember someone in this (commercial) building did something with
rigid panels on the subfloor before the carpet because the business under them was complaining about noise, but I don't know the details.

Something like one of these:

http://www.soundisolationcompany.com/products.php

[JayStPeter]

The metal channel Jim mentioned is called resilient channel (RC). It's a U or Z shaped piece of metal you hang that from your ceiling joists and screw the homasote and drywall to it. It costs around 12 cents a foot.
My personal experience with soundproofing is that it is easier to isolate sounds from downstairs making it up than sounds from upstairs making it down. I don't necessarily understand why that is. Footsteps are especially problematic. Don't misunderstand this to imply that it does nothing, it's just less effective on footsteps than anything else. Like Joe mentioned, I think the best thing in that case is to also put something between the flooring and subfloor.
IMO, the most cost effective sound reducer is plain-ol' insulation. But don't completely fill the cavity with it as a small amount of airspace is good also. Check out soundproofing.org. You can spend a couple days there trying to figure out the best and most cost effective way to go forward.
I built my shop in the basement and "soundproofed" it. Within my budget, I put 6" fiberglass in the joists, used resilient channel, then drywall. One layer of homosote and a layer of drywall is preferred, but I was already way over budget. The thing you have to be careful of when using RC is how you attach anything else to the ceiling (ie lighting). Attaching anything to the joists effectively removes the isolation of the basement ceiling from the floor above and wastes your effort. You have to be creative.

Jay

[Ray Bersch]

My personal experience with soundproofing is that it is easier to isolate sounds from downstairs making it up than sounds from upstairs making it down. I don't necessarily understand why that is. Footsteps are especially problematic.Jay

Jay & Ben;
The problem is that sound that vibrates a solid is more difficult to dampen than sound that vibrates air. So, when someone walks on a hardwood floor with hard shoes the sound (vibration) goes through the hardwood floor directly to the floor joist. If you add sheetrock to that (the ceiling of the room below) it acts as a sound board because the sheetrock also vibrates due to its direct connection to the floor joist. If you simply add fiberglass insulation between the joists you do little to deaden the sound because you have not isolated the shoe, floor, floor joists and sheet rock. Sound made from a TV in the lower room vibrates the air before it reaches the sheetrock ceiling and is thus does not vibrate the solids as much as the direct contact made by the offending shoe.

The resilient channels mentioned by Jim and Jay act as the isolator because it limits the connection between the floor joist and the sheetrock. The channel is run perpendicular to the floor joists, not along them. The channel is screwed to the joist and the sheetrock is screwed to the channel - a very effective, but not total, isolator. Yes, do put insulation between the joists but try to find an acoustical insulation for best results - check Owens Corning - and consider using an acoustical panel in place of the sheetrock to further dampen the sound - or, just require everyone upstairs to remove their shoes while you are watching the football game down in your new family room.

By the way, air gaps are excellent conductors of sound - so if you have holes in the floor, such as plumbing connections, fill the the gaps to lessen the transmission of kitchen sounds, voices, dishes clanking etc. (Boy I hate dishes clanking during a football game.)
Hope this helps.
Ray

[Chris Gregory]

Ben,

As always the information you get here is great! If you really want to isolate the sound you need to use vibration dampers which are just pieces of rubber normally with threaded rod sticking out of each end, they come in different styles and flavors but this would completely isolate the lower level ceiling from upstairs and greatly reduce any vibration/sound transmission.

Chris

[Ben Abate]

Gentlemen,

Thank you for your replies, after your comments it make me realize the difference between air vibration and sound transfer vibration. I agree that an air space is needed. You have all made me aware of the importance of isolating the transmission of vibration from the floors above. I also agree it is better to stop the sound before it gets to the floor joists by isolating the subfloor from the hardwood floor. As in most cases that horse has already left the barn and there is not much I can do up stairs.

Ray, you mentioned another type of ceiling, would you be suggesting a drop ceiling type when you say paneled ceiling. That is what came to mind when I read your reply. Actually the room is 30x20 with 3 large glass panes at one end. The other walls are concrete block covered with drywall. On the other side of one wall is my shop, which is a bit larger and on the other side is another room the same size that I eventually would like to do the same to. Home gym and small kitchen type area. So far I have built bulk heads almost completely around the entire area to house lighting for art work and accent lighting. In the center area I was thinking of using a drop ceiling but one that has sound reducing qualities. I have been looking around at some of the better companies. Companies like Armstrong offer some pretty good sound deadening numbers.

As we were saying I believe my challange is to stop or at least reduce the amount of vibration coming from the floor above. I would think that the effort taken in doing this will also take care of the sound transfer going up. I will continue to look at the sites that all of you have suggested.

Again thank you
Ben

[Stu Ablett in Tokyo Japan]

Simple, take your shoes off in the house.

I live in Japan, we take our shoes off in the house, this saves our hardwood floors and our carpets too, makes for less vacuuming and cleaning in general, as you are not tracking stuff in from outside.

If your feet are cold, buy some soft comfy slippers.

Just my two yens worth.

Cheers!

[Ray Bersch]

Ray, you mentioned another type of ceiling, would you be suggesting a drop ceiling type when you say paneled ceiling. That is what came to mind when I read your reply. Ben

Ben, I was not thinking only of a dropped or suspended ceiling. There are several alternatives, Ownens Corning is one source, they have an acoustical wood ceiling product - but don't stop there. With a little effort you will find many more products. Let your budget and ultimate goals be your guide. Generally, I don't recommend going overboard with residential sound proofing unless there is a specific situation to address - ie a lot more than footsteps overhead, simply because of the cost and complexity. Of course that is your choice. Just keep in mind some other vagaries of everyday life that may defeat your efforts, such as which doors stay open, sound transmission through HVAC ducts (a particular problem in my house), the noise level of the room you are creating, ie more attention to keeping noise out of those rooms in which quiet activities are anticipated and keeping noise in for those areas where noisy activities are anticipated.

By the way, a simple but effective way to isolate noise between rooms is to build a double wall with no mechanical connections or penetrations. A 2x4 wall along side of a wall built with 2x4's flat side out (to save space) - then fill the void with acoustical insulation and/or sheetrock both sides of one wall - they key, of course, is no mechanical connections or penetrations.

Have fun.
Ray

[Ben Abate]

Ray,

I checked out the Owens Corning site and the Soundproofing. org site. Both have a wealth of information. I am going to pursue the owens corning first. I will try to find a distributor for their goods. I called Owens Corning and they told me Lowe's or HD. The items are special order for these two but I can at least get a price.

I liked all of the ideas on soundproofing. org but, I would loose the ability to have access to the mechanicals in the ceiling. I like being able to access that in case of what ever. If I were to build new I would take a of what they have to say. I could use some of their ideas in almost every rooim in my house.

well thank you for the info.

Ben