I’m currently building in NH and am close to the drywall stage. I am wondering if it is worth insulating between the rooms (partition walls and ceiling/floor joists)
Some info on the house. SIP construction with 12″ I joists for first and second floors. Sandwich type radiant heat installed in all rooms. (on top of subfloor with pex-al-pex tubing and aluminum plates.
I am thinking that I should certainly insulate the floors to get the best performance out of the radiant heat. is there much benefit to doing the party walls and what type of insulation would you recommend. I am considering fiberglass batts or blown cellulose.
Pros/cons anyone??
Tom
Douglasville, GA
Replies
party wall???
more than one family dwelling???
insulation between rooms is good for sound control...
good plan on insulating the floors...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Party wall = too darn late at night to type out partition again:)Tom
Douglasville, GA
High or low frequncies?There are neat systems to suspend the drywall off the studs to prevent transmission of low frequencies for commercial construction.Thick rubber sheets between the studs are used in sound studios.I used cellulose between a hardwood floored living room and a downstairs home theatre; it was big help but didn't stop the elephant herd effect.Or just try putting a layer of 1/2" fiberboard ( buffalo board, celotex)
under the drywall on one side. Cheap, fast, easy and effective.
Here's the conclusions of an older study on sound transmission through stud walls of different configurations. I don't suppose the physics has changed much in ten years.
https://www03.cmhc-schl.gc.ca/b2c/b2c/productdetail.do;z_ItemID=00000000380000000022;jsessionid=ID1253371108DB0.8565756709888381End
Most of the little I do know about sound transmission has come from reading CMHC stuff and from talking with a movie sound tech I used to know.
There is more available on the CMHC site, but most of what is being talked about here is in that one study.
Ron
he can hit overkill here in a heartbeat or less....
Celotex and 5/8" DW is a good move ............
but.........................
now we are into extended jambs and a whole array of something elses to deal with... sound batts and call it a day....
BTW... the discussion was wall insulation for sound and thermal and floors with radiant heat...
still believe the floor needs insulation......Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
"BTW... the discussion was wall insulation for sound and thermal and floors with radiant heat...
still believe the floor needs insulation......"
I agree absolutely. Heat travels to cool. It also takes the path of least resistance. It doesn't matter how big the delta T, that only affects the rate of heat transfer. Even if your radiant tubes are mounted above your 3/4" subfloor that's roughly R-3.5 on the bottom side. Depending on your floor covering you can easily exceed that on the top side. And of course as everybody knows, heat does not rise, hot air does!
I generally figure as a rule of thumb, 4 times the R value insulation below the floor as above to be sure my heat is going where I want it. If you skip insulating between floors with radiant heat your drywall has so little R value you will absolutely have problems controlling temps in the areas below it.
My two cents! :)
Rich
I've got the absolute best , fastest , and cheapest method of all. Earplugs. Just kidding! But seriouly, I have an idea I was thinking about trying in the house I'm currently building. Hanging two sheets of 5/8'' sheet rock on the ceiling of my first floor living room. That way it wouldn't be to expensive because you don't have to finish the first layer of drywall and you'll just need some longer mud rings and drywall screws in the ceiling. You could even wait to hang that room last so you could use waste pieces for the first layer in the ceiling. Good or bad idea? By the way, I used the ear plug idea while I was trying to sleep when I was at the '05 Sturgis bike rally. It worked! 96 1340.
Like second poster said, insulate floors. I understand there are better things than fiberglass for sound insulation. I would use sound insulation between bedrooms and around bathroom. (Rock wool maybe?)
rock wool??????
ya can't be serious...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
Hi Marty, long time!?!Why not rock wool? Just curious. Our inspector requested it for sealing gaps between shell and scribed ply on second floor for fire protection...so that's been my only use of it.
poor R return and that is some nasty stuff...
sound batts are soooooooooooooooooo much gooder....
I only use it to treat / rub on toilet paper ...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
You should insulate under the floors to keep the heat moving in the right direction. Fiberglass batts will work fine and go in easy in this application. I'm not a believer in the foil bubble sheets. Because your radiant is going on top of the floor, you can insulate right up to the bottom of the subfloor. As far as the walls go, unless you plan on large temp differences between rooms you don't need it there for heat, but I would do it for sound. I use fiberglass there also but if there's other ideas that work better for a reasonable cost, I'd like to hear about them too!
Regards, Rich
To preserve your sanity, I'd consider anything but fiberglass in the ceiling. It just brings up too many unpleasant memories of cold showers trying to get all the FG out of my skin. There are many other materials like dense-pack cellulose, Icynene, wool, etc. that go on easy w/o the itch.Insulating between floors is a really good idea, particularly if you're intending on zoning up the house and/or want to use floor rugs in some rooms. The more insulation RFH encounters going up, the more insulation you need below to make it go that way despite the floor coverings.Dense fiberglass between rooms is a good start, building walls with offset, staggered studs (so that no stud traverses the whole wall thickness) is even better.
Insulation in interior walls does nothing. Some think it is a sound deadener, but it is not. If you want to cut down on noise, the sheetrock is hung on rollformed steel resilient channels screwed horizontally to the studs on 16" centers.
Sounds like your radiant tubing is on top of your subfloor, between the subfloor and finish flooring. In that case, insulating under the floor does little good.
Put the money somewhere else! I am sure there are lots of ways.
Couldn't agree more.
The only folks I know that recomend insulation for sound control are folks who sell insulation.
J. D. Reynolds
Home Improvements
I'm no expert, but there are conditi0ons under which FG insulation will make a difference to sound transmission.
If you interrupt the the continuous sound path from one wall surface to the other , say, by adding resilient channel, then FG insulation in the stud bays will absorb a worthwhile amount of airborne sound. Same with light steel stud framing- hanging some FG in the stud bays will absorb airborne sound and prevent some of it from crossing.
With solid wood studs, so much of the sound is transferred right through the wood that there is no point in worrying about the sound that is transferred through the air space.
Ron
I can't completely disagree with you....not being an expert on sound transition either...but my personal experience has been that results are negligable when weighed against the costs of adding the insulation.
J. D. Reynolds
Home Improvements
Agreed.
Mass counts more than anything, but separation is the big second. Fiberglass does neither.
In doors for example, a solid wood door carries a lower STC (sound transmission coefficient) than a foamfilled steelskinned door. An example of mass.
In windows, airport construction design uses laminated glass in those large windows you look through from the gate lounge areas. Hear those jet engines? Not too much, right? An example of separation. The laminate layer in the glass sandwich is a cushion.
If I wanted to minimize sound transmittance through the walls of adjoining rooms, I might try some or a combination of these methods:
Use 2x6 plates, frame with 2x4 studs on 12" centers, alternating, so sheetrock each side is fastened on 24 centers. Makes each side's rock independent of other side.
Use rollformed steel RC channel hung horizontally to studs on 16" centers. Fasten rock to RC channels.
Add mass by upping rock thickness to 5/8".
Fasten first a cushioning layer of material, Homosote maybe, to studs before sheeting with gypboard.
NOT fasten the headboard of the bed to the wall! ;-)
>Mass counts more than anythingWhy are recording booths faced in foam?I've been told that different material masses limit transmission of sounds at different frequencies, so that a mixture of materials would work best to limit transmission of the full spectrum of sound. Yes? No?
A recording studio is completely different case.They are not as concerned about the sound going out as they are sound coming in.Also they want to deaden the reverb of the sound produced in the room so that they have full controll on what and how they mix and add any reberb that they want.
>They are not as concerned about the sound going out as they are sound coming in.Doesn't out and in depend on which side of the wall you're on?
Jim,I think the difference with a recording studio is that the foam is on the outside of the wall, meaning it's the first layer (as opposed to FG batts in between the GWB).The foam can reduce both the airbore sound waves and also acts as a buffer to keep the vibration from the sound waves in the wall cavity down as well.With FG any noise traveling throught the stud bay may be reduce but the GWB on both sides will still resonate since the studs provide a "condutcor" for that energy.But hey, whadda I know...?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
>With FG any noise traveling throught the stud bay may be reduce but the GWB on both sides will still resonate since the studs provide a "condutcor" for that energy.Certainly. But that's not the whole story.I have a powder room at the intersection of the library, dining room, living room. Convenient placement, except for the potential for noise of the toilet variety. I staggered the studs to avoid transmitting sound the way you described. Resilient channel wasn't an option be/c both sides were plastered and not rocked. Filled the empty spots with fg be/c that's what was most available.If I postulate that the fg there was better than having empty spaces, will y'all agree or disagree? Foam woulda been better than empty. Packaging peanuts woulda been better than empty. Just about anything not too dense that won't decompose would be better than empty. OTOH, filling with a dense material would not help. It'd become a conductor, especially for the lower frequency sounds. Yes? No?Or, consider Mike Smith's current house. He'll probably fill the walls with cellulose. I'll postulate that that house with the filled walls would be quieter inside than an identical one with empty cavities, all other things being equal. Yes? No? Now, it'd be awfully interesting to use that house for our experiment and fill the cavities with a variety of materials and test the sound transmission. A quick google didn't turn anything up. Anyone know of real testing on this, instead of just our speculation?
Jim,I completely agree that FG is a help. In fact, that's the one of the first methods I turn to when a client wants quiet (typically basments with media rooms). Fiberglass may not be a panacea, but I look at it like a drag racer comparing tire choices with my commuter neighbor. One required high performance, the other just requires performance.From the reading that I have done, you can go crazy with soundproofing and decoupling, but most don't want to invest the thousande (tens of thousands???) necessary for a subwoofer in one room to be unnoticed in the adjacent room. FG & resilient channel will do significantly better than a conventional wall assembly.One question, why do you say you could not use RC for your powder room? Doesn't your plaster go on top of a blueboard that is fastened just like GWB?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
>Doesn't your plaster go on top of a blueboard that is fastened just like GWB?Not that room. 4' radiused walls, so 3 coat plaster over mesh.
Cloud,You wrote, "If I postulate that the fg there was better than having empty spaces, will y'all agree or disagree? Foam woulda been better than empty. Packaging peanuts woulda been better than empty. Just about anything not too dense that won't decompose would be better than empty. OTOH, filling with a dense material would not help. It'd become a conductor, especially for the lower frequency sounds. Yes? No?"You are correct that most fillings will perform better than plain air at stopping sound. You are wrong about the denser fillings, because not all dense fillings are good sound conductors. Dry sand, for example, is good for suppressing low frequency sounds. Sheet lead is also very good because it is dense and limp at the same time. 1/8" sheets of pure 24 karat gold would perform even better because far denser and also limp. But I never see it used...cheap penny-pinching owners!But seriously, a dense filling can have both a benefit and a detriment to sound control. The benefit is that it takes energy to excite it, some of which turns to heat. The detriment is that the material may recouple the wall planes and conduct sound through the assembly. Knowing this, you can design the partition to maximize the pros and minimize the cons.By the way, my own experience is that plaster on wire lath is very good for sound walls, and more so when curved. I think the curve inhibits the oscillations of the wall skin.Bill
In a recording studio, the foam on the walls is to kill the reverberations internal within the room, which is not the same as transmitting sound between rooms.
Reverb is at high frequencies and is easy to damp. Sound transmission from the outside is typically low frequency and is real hard to damp cuz it is traveling thru the physical structure of the building. Which is why real sound-proofing often uses double walls with offset studs, which breaks the direct mechanical path.
One thing often overlooked regarding damping transmitted sound; air gaps. Sound is moving air, sealing all the gaps will often make a big difference at speech frequencies. Duzn't do squat for the sub-woofer below the baby's bedroom, though.
I would strongly suggest insulating between the first and second floor with 12" I joist construction. I did the same contruction in my house and it seems to transmit sound very nicely.
My insulation guy suggested insulating between the floors for thermal and noise reasons. I wish now that I did it for the noise isssue.
I used dense pack cellulose in the walls and the second floor ceiling. I'm sure it would have helped reduce noise transmission in the first floor ceiling.
I would also insulate the stud bays the drain pipes from the second floor are located in. Good luck with the new house!
It is a waste of money to insulate between interior spaces. Heat travels from warmer temperature to colder. The rate of heat transfer is proportional to the temperature difference. If the rooms are only a couple of degrees apart you'll get negligible heat flow anyway. You'd just be throwing money away.
As for sound insulation, regular fiberglass and rock wool are not dense enough to do much. The current issue of The Journal of Light Construction has an outstanding article on sound control, if that is your concern.
Simple unfaced fiberglass bats on interior walls does make a significant difference. It gives the rooms a different feel since it does quiet things down. The better houses I've worked on have 2x6 interior framing, unfaced bats, and 5/8" rock instead of 1/2". Very nice.
For a top of the line job that's still the way I'd go.
My house has rf heat, 15 zones and 15 thermostats. I have insulation in every place I could put it. My heating bill will be just under $300 this heating season with a wife that likes it at 75. My DirecTv costs are higher than my heat costs. I burn NO wood only Lp gas. I keep the rooms being used warm and those not being used at 55.
I have a 17 year old son and his music seems to stay in his rooms.
I think I spent about $4.500 on insulation for 7,800 sq ft of living space.
My last house was 4,500 sq ft with season heating bills of over $1,500.
That's how insulation is working for me in Central Va.