{"items": [{"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925568047092", "anchor": "fb-925568047092", "service": "fb", "text": "One question that might be useful to answer is, how bad is the current level of sound transmission compared to other similar houses? The idea is, if it's worse than normal it's probably easier to fix. In our house we have a bunch of different kinds of floor / ceiling combinations, so I was thinking this might be a good test:
* get a weight and a pad to drop it on
* set up a microphone in the room below
* drop the weight at measured heights
* do this for several pairs of upstairs/downstairs rooms
* compare dB in the recordings for the same height of drop
Another way to do this would be to use a recording played pretty loud on a speaker that can do low frequencies, but I suspect that doesn't simulate foot traffic as well?", "timestamp": "1517924852"}, {"author": "George", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925569953272", "anchor": "fb-925569953272", "service": "fb", "text": "Instead of doing something to the ceiling, how about padding on the floor above?", "timestamp": "1517925716"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925569953272&reply_comment_id=925571300572", "anchor": "fb-925569953272_925571300572", "service": "fb", "text": "→ \"We tried putting down half inch foam on our floor above, but that didn't noticeably help.\"", "timestamp": "1517926506"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925569953272&reply_comment_id=925576794562", "anchor": "fb-925569953272_925576794562", "service": "fb", "text": "→ Jeff Kaufman the type of foam makes a huge difference.", "timestamp": "1517928048"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925569953272&reply_comment_id=925605666702", "anchor": "fb-925569953272_925605666702", "service": "fb", "text": "→ It was: https://www.amazon.com/dp/B013A4ASRW/", "timestamp": "1517934958"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925569953272&reply_comment_id=925605921192", "anchor": "fb-925569953272_925605921192", "service": "fb", "text": "→ \"High density EVA foam\"", "timestamp": "1517935082"}, {"author": "Eileen", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925571839492", "anchor": "fb-925571839492", "service": "fb", "text": "Any chance you could get insulation blown in to the space between the floors? I know our situation is different but we had it blown into the garage ceiling which is under the kitchen, and it\u2019s wonderful for heat loss. The outside walls were also done and the sound reduction was quite dramatic.", "timestamp": "1517926807"}, {"author": "Josh", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925571839492&reply_comment_id=925615162672", "anchor": "fb-925571839492_925615162672", "service": "fb", "text": "→ I was wondering about this too. I guess the efficacy of insulation would depend on whether sound is being conducted mostly thorough the air or mostly through the joists. If it\u2019s the air blowing in some foam ought to do the trick, no? If it\u2019s the joists you\u2019d need to add something to absorb the vibrations before they get to the ceiling.", "timestamp": "1517937719"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925584010102", "anchor": "fb-925584010102", "service": "fb", "text": "The solutions for different types of noise problems are different. Airborne sounds (speech, intelligible music) may indicate a transmissive path such as a small hole in the floor or gaps in the floorboards that can be repaired (check where heating pipes pass through the floor as well). Low frequency thumping from stereo equipment can be increased by speakers placed directly in the floor. Foot traffic noise could be helped by some form of dropped ceiling or by padding above, but could also indicate problems with joists or flooring, especially if excessive squeaking is involved. Special carpet padding exists that's DB-rated if it's just the actual thumping of feet. Negotiations about quiet time are also an effective tool.", "timestamp": "1517928590"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925584010102&reply_comment_id=925587802502", "anchor": "fb-925584010102_925587802502", "service": "fb", "text": "→ I missed the details in your OP when I wrote the above. Will get back to you later when I have a real keyboard. I'll note that 3/8 is very thin for a ceiling; the original plaster was probably an inch or more.", "timestamp": "1517928891"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925595766542", "anchor": "fb-925595766542", "service": "fb", "text": "My first take on a solution would be to have a dropped ceiling below the existing ceiling, perhaps 2-3 inch gap. Hang the dropped ceiling with sufficiently springy hangers, to reduce sound transmitted through the solid structure. Put some sort of spongy material in that 2-3 inch gap, to reduce noise transmitted through the air space from old ceiling to new ceiling. Yes, you can get a hung ceiling which isn't too ugly -- look for ceiling tiles with recessed edges, so the metal strips of the hung ceiling are in the recesses between tiles.", "timestamp": "1517931573"}, {"author": "Elena", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925608830362", "anchor": "fb-925608830362", "service": "fb", "text": "When I was looking into this, the thing that looked best to me was a combo of mass-loaded vinyl and quietrock (or other specialized acoustically dampening drywall)", "timestamp": "1517936198"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925608830362&reply_comment_id=925611035942", "anchor": "fb-925608830362_925611035942", "service": "fb", "text": "→ It looks like mass loaded vinyl needs to be able to freely vibrate? How were you thinking of setting that up?", "timestamp": "1517936757"}, {"author": "Elena", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925608830362&reply_comment_id=925613151702", "anchor": "fb-925608830362_925613151702", "service": "fb", "text": "→ The ceiling joists here are exposed - iirc the idea I settled on was to affix the mlv in the void between the joists and then drywall as normal but with quietrock (I never actually did this, though, so I can't tell you how it turned out!)", "timestamp": "1517937407"}, {"author": "Kelly", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925610741532", "anchor": "fb-925610741532", "service": "fb", "text": "following because i would like to know very much. i am awakened several nights a week by a child crying in the room above mine, followed by the thunderous stomping of the adults coming to attend the child.", "timestamp": "1517936632"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925610741532&reply_comment_id=925611230552", "anchor": "fb-925610741532_925611230552", "service": "fb", "text": "→ How much control over the space do you have? If installing a drop ceiling ended up being a could solution could you do that?", "timestamp": "1517936805"}, {"author": "Kelly", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925610741532&reply_comment_id=925611534942", "anchor": "fb-925610741532_925611534942", "service": "fb", "text": "→ Jeff Kaufman i could potentially attach things to the ceiling but i would have to remove them when i leave. there are fixtures in the ceiling that i can\u2019t modify like the sprinkler and fire alarm, so i would have to work around that.", "timestamp": "1517936922"}, {"author": "Kelly", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925610741532&reply_comment_id=925612263482", "anchor": "fb-925610741532_925612263482", "service": "fb", "text": "→ i also feel like it would require more than modifying the ceiling. i can feel the stomping through the walls, and objects adjacent to the walls rattle.", "timestamp": "1517937058"}, {"author": "Les", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925617488012", "anchor": "fb-925617488012", "service": "fb", "text": "I've participated in a project to reduce sound transmission. One of the culprits was balloon framing. Placing a large rug on the upper floor helped.", "timestamp": "1517937937"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192", "anchor": "fb-925630871192", "service": "fb", "text": "This is just one of a number of websites I have found for sound absorbing carpet pads. I think these types of materials in combination with a conventional carpet would help a lot to prevent the noise from being created in the first place. They're not cheap, but much cheaper than the dropped ceiling quotes you've gotten.
https://www.soundisolationcompany.com/.../carpet-floors/", "timestamp": "1517943211"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925631739452", "anchor": "fb-925630871192_925631739452", "service": "fb", "text": "→ This area (dining room) isn't carpeted, and wouldn't make much sense to carpet, though.", "timestamp": "1517943695"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925632702522", "anchor": "fb-925630871192_925632702522", "service": "fb", "text": "→ Jeff Kaufman How about a playtime matt that gets rolled out between meals, rolled up during meals?
Only the areas not covered by the dining table should be an issue.", "timestamp": "1517944090"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925632832262", "anchor": "fb-925630871192_925632832262", "service": "fb", "text": "→ We tried a mat (that we left down) and it didn't seem to do anything.", "timestamp": "1517944184"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925632837252", "anchor": "fb-925630871192_925632837252", "service": "fb", "text": "→ Also, a rubberized material (perhaps even just the underlayment, if you choose one of the more durable and waterproof versions) acting as a carpet, but food- and play-safe, could be something sensible while the kids are growing up, to be removed once they are no longer running excitably around?", "timestamp": "1517944186"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925632937052", "anchor": "fb-925630871192_925632937052", "service": "fb", "text": "→ The kids mostly don't play there, but they do pass through there going between other places.", "timestamp": "1517944222"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925633096732", "anchor": "fb-925630871192_925633096732", "service": "fb", "text": "→ Jeff Kaufman Another possibility is a false floor over something like this: https://acousticalsolutions.com/.../iso-step-floor.../...", "timestamp": "1517944332"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925633500922", "anchor": "fb-925630871192_925633500922", "service": "fb", "text": "→ Jeff Kaufman Are they barefoot at home? The difference between bare feet and shoes is large.", "timestamp": "1517944432"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925633560802", "anchor": "fb-925630871192_925633560802", "service": "fb", "text": "→ (I imagine they are, but am trying to avoid assumptions)", "timestamp": "1517944449"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925630871192&reply_comment_id=925636260392", "anchor": "fb-925630871192_925636260392", "service": "fb", "text": "→ Yes, we switched them to consistently barefoot at home to try to reduce noise", "timestamp": "1517945589"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925633426072", "anchor": "fb-925633426072", "service": "fb", "text": "Before I do anything more complicated, I would try one of the sound absorbing carpet pads I mentioned -- which you've already been pointing out may not be effective in your situation. However, I think any treatment to the floor of the upstairs rooms will be cheaper than any treatment to the ceilings of the downstairs rooms.
You appear to be mainly concerned about footfalls, which are the most difficult things to deal with. Several people have already talked about putting in a dropped ceiling of some sort -- whether a conventional dropped ceiling tile, a modified dropped ceiling tile, or a plaster/drywall/mlv/quietrock new ceiling below the existing ceiling.
I prefer the latter, and as I mentioned casually before, I think a 3/8\" drywall ceiling is part of your problem; because it's so thin, it will retransmit higher frequency sounds and retransmit low frequency sounds at higher volume than a thicker, heavier ceiling would.
So I am a fan of some sort of soft absorptive material (to be researched) between the existing joists and the new furring strips, then a heavy false ceiling made of quietboard and/or other new acoustically inert materials.
I think you could do some or all of this yourself, if you chose, and that it might make sense to do the first part yourself, then bring in plasterers to do the second part -- so you're doing the fussy-but-not-highly-skilled bit of installing all the supporting material and decoupling the new ceiling from the old, and they're doing the quick-and-easy-but-skilled lifting of heavy materials into place, fastening, skim coating and painting. Then you can choose whether to add crown and/or picture molding, or leave that choice to your tenant.
A question that Kelly raised about whether some of the transmission is through walls, rather than just floor-to-joist-to-ceiling. If that's the case, then if you can rearrange the upstairs space so that footfalls are less likely to occur near the tops of the walls below, that would help. This could be a matter of rearranging furniture. From the floorplan you posted, it looks like the only place where this might be happening is in the doorway between dining room and living room. Placing extra carpeting there, or putting a soft barricade in place when not actually dining, or just training the kids to stop, wait, listen, and proceed with caution when passing through that door, could help -- if that's an issue at all.", "timestamp": "1517944395"}, {"author": "Alex", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925633750422", "anchor": "fb-925633750422", "service": "fb", "text": "I asked a sound engineer friend about this about 5 years ago from his experience with building a home recording studio. He said double layer of drywall is the best balance of cost effective & effective effective.", "timestamp": "1517944606"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925661310192", "anchor": "fb-925661310192", "service": "fb", "text": "It really depends on the frequency of the noise you are trying to block out on whether those noise dampening carpets or wall baffling will help.
High frequencies tend to be lower perceived amplitude and do not resonate well with materials, so those are fairly easy to block (just make sure to close off any open air and that usually does the trick). Mid frequencies are generally the most affected by wall baffling and noise dampening carpets. They're the most 'noticeable' noises to human ears, so this is good... but they are a small part of the spectrum.
Low frequencies tend to be the hardest to mask. If you do that microphone test make sure you pay attention to a spectrum analyzer when looking at the audio files. That way you can classify your noise pollution and find the frequencies it is the worst.
Since it's basically impossible to isolate the house from itself, adding insulation and carpeting to \"stiffen\" the walls and ceilings and reduce its resonant frequencies can help a lot with perceived low frequency noise. Soft feet on hard wood floors is actually quite quiet if the floor is very stiff, but most floorboards in houses are fairly thin boards that are springy and therefore resonate, a lot.", "timestamp": "1517958063"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925661310192&reply_comment_id=925676739272", "anchor": "fb-925661310192_925676739272", "service": "fb", "text": "→ In this case the main problem is low frequency thumping sorts of sounds.", "timestamp": "1517966404"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925661310192&reply_comment_id=926062311582", "anchor": "fb-925661310192_926062311582", "service": "fb", "text": "→ Yep. Those are usually the culprits. Baffling will not really help at all with low frequency. replacing, or adding to your flooring material will help, but it has to be very absorptive to cancel out the 'drum' effect of hardwood floors. If you use the hardwood as a base and roll out something like this: https://www.amazon.com/UltraSeal.../dp/B00E4U2YFQ... and then use some quick-locking vinyl tiles over it, that can make a big difference.", "timestamp": "1518129927"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925661310192&reply_comment_id=926062406392", "anchor": "fb-925661310192_926062406392", "service": "fb", "text": "→ It won't eliminate the thumping though, unless you can get like 2\" of the rubber in there :-P", "timestamp": "1518129973"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=925661310192&reply_comment_id=926082770582", "anchor": "fb-925661310192_926082770582", "service": "fb", "text": "→ I'm looking at doing something like: http://www.soundproofingcompany.com/.../spc-3-soundproof.../", "timestamp": "1518134277"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926101587872", "anchor": "fb-926101587872", "service": "fb", "text": "Wow! That looks very nice! It also looks like overkill --a question here is, are you looking for the best solution, or for a cost effective solution that's good enough? How much sound do you have to block to make the tenants happy?
That said, I'd love to see (and hear!) the results!", "timestamp": "1518140634"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132", "anchor": "fb-926128404132", "service": "fb", "text": "The system shown in the link you give above, does indeed seem like overkill in your situation. I'm sure that low frequencies will transmit through the joists much better than through the air between the joists, so insulation within the air space between the joists will not likely be cost-effective for your situation. Leave the existing drywall ceiling, it doesn't gain you much to remove it. I love the sound isolation clips, which give you the springy support which is most important, and probably also good damping in the springy support which will also help. And the clips apparently have interlocking metal parts, so if the rubber eventually fails (which it probably won't anyway), the ceiling will not fall more than a fraction of an inch -- this makes it quite reasonable to hang a heavy drywall ceiling below. All of that seems like a straightforward balance of cost and trouble, versus effectiveness. I do not know what to say about the type or thickness of drywall to be hung from the clips, or whether to use the \"Green Glue\" damping product. If you can leave the new drywall ceiling disconnected from the walls, that might help. At some level of soundproofing of the ceiling, the transmission of the footfalls down the walls around the new drywall ceiling will be the major remaining problem, and better soundproofing of the ceiling will not benefit you much by that point.", "timestamp": "1518150611"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926183049622", "anchor": "fb-926128404132_926183049622", "service": "fb", "text": "→ Part of what that's proposing is damping the floor above by attaching two layers of drywall and green glue. This seems like an important step to me, since it looks like reducing sound as close to the source as possible is best.", "timestamp": "1518180335"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926189391912", "anchor": "fb-926128404132_926189391912", "service": "fb", "text": "→ Think about thermal insulation of an exterior wall. Making the wall thicker will help to some extent, but heat travels through the studs. Making a wall with 2x6s 24 inch on center, rather than 2x4s 16 inch on center, allows more insulation between the studs, and has 33% fewer studs, but still the heat flow through the studs is a problem. Making the same thickness wall with alternating 2x4s, half touching the sheathing and half touching the drywall -- or any other way to avoid a direct heat conduction path through the wall -- is a great help in this regard. Where a wall is already built, a solution is to use a thickness of insulating foamboard on the sheathing, under the siding, and this is a lot more benefit than you would expect from the thickness of the foamboard, because it's not just adding to the thickness of insulation between the studs, it's preventing direct heat transfer from siding to sheathing to studs. Apply this to your sound isolation problem. Yes, the added mass and damping of the double drywall and Green Glue under the floor between the joists must have some benefit, but is it really worth opening the ceiling below to add this, or to add sound insulation between the joists? A thin flooring underlayment above -- either an underlayment under an added floor, or a carpet pad under a rug -- would probably help as much, because it interferes with the conduction of the footfalls directly to the joists. And it is so much easier to add a new ceiling below, with the springy supports, than to make any change above. Do the new ceiling below. The only reason to later consider the underlayment and new flooring above, would be if the transmission of the footfalls to the floor and thence to the walls of the floor, and thence down to the walls of the room below, remains a problem.", "timestamp": "1518184531"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926207715192", "anchor": "fb-926128404132_926207715192", "service": "fb", "text": "→ I don't see where stiffness and damping fit into the heat insulation analogy, and those are the two main reasons to demo the ceiling and attach drywall to the underside of the existing subfloor.", "timestamp": "1518186689"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926217051482", "anchor": "fb-926128404132_926217051482", "service": "fb", "text": "→ Michael Your comments are definitely valid but there's one key point in sound isolation that is very different from heat- the source of the sound waves. Heat AND sound waves will transfer through joists, yes, but the cause of the low-frequency sounds is the floor flexing. It's very much like a drum. If you stuff a drum full of stuff it can muffle the sound, but if you stop the drum head from being able to resonate, that has a MUCH larger effect. There is a reason that drum mutes are just pieces of rubber you place over the drum head.
That's the same idea with the double drywall plus \"green glue\". The glue is a hugely important component of that, by the way. I've seen it in use but I had forgotten about it. It dries to become super stiff and inflexible, providing much better resonance damping than just two layers of drywall against each other.
This project looks really neat, Jeff. Definitely a lot of work, but it could be worth it for these common rooms over bedrooms kind of situations.", "timestamp": "1518189746"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926217405772", "anchor": "fb-926128404132_926217405772", "service": "fb", "text": "→ (This is also a good comment on why acoustics are not considered in pretty much any regular home- acoustic insulation is uniquely different and often opposed good design for heat insulation. Also, drywall makes a great resonator on its own, but it's one of the cheapest and most effective building materials if you do not consider that aspect... so...)", "timestamp": "1518189958"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926218508562", "anchor": "fb-926128404132_926218508562", "service": "fb", "text": "→ Jeff Kaufman Just saw your first comment there, \" This seems like an important step to me, since it looks like reducing sound as close to the source as possible is best.\" - yes, yes yes. Stiffening the floor will make a huge difference. The cutout on that site shows the drywall under the subfloor, though. It may be more economical + work better to instead take the floor up from above and place a layer of double drywall + hard glue over sound isolating rubber over the replaced floorboards.", "timestamp": "1518190387"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926224331892", "anchor": "fb-926128404132_926224331892", "service": "fb", "text": "→ Greg, you obviously know more about this than I do. But I will throw a question back at you. First, I will understand and agree that, when someone walks on the floor above, the floor will resonate, and this will make their footfalls loud in that room above. And if there is mass and damping (drywall and Green Glue) under the floor, that will greatly reduce the loudness of that noise in that room above. And it will somewhat (not sure how much) reduce the transmission of the sound to the ceiling below.
But my questions for you are ... How much will the mass and damping reduce what is transmitted to the ceiling of the room below? How much will a spring-support additional ceiling in the room below, reduce what is transmitted to the (new) ceiling of the room below? The comparison of these two projects will help Jeff decide whether it is worth doing the mass and damping under the floor above, or the new ceiling below, or both. (I can't evaluate the comparison, but I know that the new ceiling below will be much lower cost, compared with opening up the ceiling to do the mass and damping under the floor above, or taking up the floor above and reconstructing it as you suggest.)", "timestamp": "1518192494"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926228708122", "anchor": "fb-926128404132_926228708122", "service": "fb", "text": "→ That's the important question, isn't it :-). I should note- my knowledge in this area is based on having hobbyist level interest in acoustics engineering and through being a musician for most of my life, coupled with having a bit of construction experience owed to my father. I never studied it in an academic or professional setting.
So, I'm working on my best guess, which is more informed than many but I would definitely not accept what I say as totally true, and I'm the one saying it :-)
My best guess is that adding a spring-support ceiling by itself (without going in and stiffening the subfloor) will dampen high and mid frequency sounds pretty effectively, but will not have a large effect on low-frequency thumping. The 'attack' of the footfall will be muted, but the corresponding low-frequency reverberations will continue mostly unabated: that resonates through the walls just as well as it resonates through the ceiling. The crucial aspect to eliminating the resonating footfalls is to stop the floor from acting like a drum head.
The problem with this assumption is that it's just that- an assumption (albeit slightly informed).
A microphone and spectrum analyzer should definitely be used to get the resonant frequencies in the lower room. Then, I would suggest laying out a thick piece of foam (2\"?) and then, over top of it, a thick/stiff piece of wood, and walking over that, measuring the amplitude of relevant frequencies below once again. This should be a relatively inexpensive test to rig up, and can help deciding in whether just adding a muting ceiling to reduce the harshness of the sound, or fully stiffening the floor to reduce the low frequency reverberation, will be most effective.", "timestamp": "1518194329"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926128404132&reply_comment_id=926230729072", "anchor": "fb-926128404132_926230729072", "service": "fb", "text": "→ Vague thought not to be confused with real analysis -- Maybe an acoustic rubber pad under a new flooring (hard floor or rug) above -- or the added mass and damping for the floor above -- will be helpful for one range of frequencies, while the extra sound-isolated drywall ceiling below will be helpful for a different range of frequencies. If so, it could be important to do both.", "timestamp": "1518195221"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926231352822", "anchor": "fb-926231352822", "service": "fb", "text": "As a separate matter, I will suggest the importance of redundancy for the attachments for the new (heavy) drywall ceiling below. The sound isolation clips mentioned in your link look great, for new construction, where you know that each clip is securely mounted to carry the weight of what is hung from it. For an old home, and especially if you will be screwing up through existing drywall into joists that you cannot see, you want many more attachment points, so that if some of the attachment point are not secure, there is still sufficient redundancy that the heavy new ceiling will not fall. You need a large number of sound isolation clips, each of which is designed for much lesser load, compared with the system you give the link to, which has very few clips, each of which carries a large load.", "timestamp": "1518195473"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926231352822&reply_comment_id=926249631192", "anchor": "fb-926231352822_926249631192", "service": "fb", "text": "→ The sound isolation clip manufactures all strongly recommend against installing over existing drywall.", "timestamp": "1518203010"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926231352822&reply_comment_id=926419226322", "anchor": "fb-926231352822_926419226322", "service": "fb", "text": "→ Returning to this topic, the solution is obvious. Furring strips, good quality wood, attached through existing drywall with great redundancy. Then sound isolation clips mounted to the furring strips, in the same manner as done to studs when there is no existing drywall.", "timestamp": "1518265581"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926231352822&reply_comment_id=926420109552", "anchor": "fb-926231352822_926420109552", "service": "fb", "text": "→ Michael: \"installing over rigid surfaces like drywall or plywood is possible, but will seriously reduce performance. Reduce the loss in performance with R-6 fiberglass batt insulation between the furring hat channel and the existing surface.\"
http://isostore.com/faq/resilient-sound-clips/", "timestamp": "1518266559"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926231352822&reply_comment_id=926420359052", "anchor": "fb-926231352822_926420359052", "service": "fb", "text": "→ Looking at their measurements, they say adding a layer of drywall with clips over existing drywall adds 5 STC points, while demoing the existing drywall first would get you 9 STC points. They don't have IIC numbers, though, which is more what I care about.
http://isostore.com/shop/product/pliteq-genieclip/", "timestamp": "1518266774"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422", "anchor": "fb-926233049422", "service": "fb", "text": "Hmm. Looking at it more carefully, it appears to be showing thin pieces of plywood as \"joists\". It's unclear to me where the real joists, that actually support the floor, are, and how they're being handled.
Aside from that, there's no sign of any diagonal bracing, which may or may not be present. If it is, installing those narrow bits of drywall will require removing it. Probably not a real problem.", "timestamp": "1518196082"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926233598322", "anchor": "fb-926233049422_926233598322", "service": "fb", "text": "→ The \"joists\" shown in the link that Jeff provided have thin flakeboard webs between good wood top and bottom caps. They are very good engineered joists. They use less wood overall, and some of that is flakeboard which is made from wood flakes which are otherwise not good for much.", "timestamp": "1518196277"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926234656202", "anchor": "fb-926233049422_926234656202", "service": "fb", "text": "→ Hit return too soon.
I return to my earlier question: how much noise reduction do you need? The design, as shown, seems eminently suited for doing in stages, with testing in between, and stopping when adequate results have been achieved, if the timetable and/or tenant are amenable. Will adding mass and stuffness to the sub-floor alone be sufficient? (I ask this in all seriousness; I think it may)
Another thought is that, once you have actually removed the existing ceiling, you have the option of constructing something similar to a traditional sound isolation wall, as found in recording studios, with alternating studs. I say \"similar\", rather than \"the same as\", because you probably don't want to have that second ceiling suspended only by its edges, for a number of mostly obvious reasons, so you would need something like the clips. I think I bring this idea up only to discard it, as it would be labor intensive and use cheap materials, which is not a win in this situation.
Looking at the SPC page, I'm thinking that SPC Solution 1 is similar to older homes that you're comparing to -- which are tolerable but not ideal, but probably by far the cheapest solution.", "timestamp": "1518196655"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926235409692", "anchor": "fb-926233049422_926235409692", "service": "fb", "text": "→ Arrgh. Social Solver is supposed to keep that annoying thing from happening! I had better check my settings.
Anyway, where I was going is that whether SPC2 or SPC3 or a new, let's call it SPC 1.5, solution that includes the treatment to the underside of the sub-floor but not the clips, makes the most sense (economically) may depend on the construction revealed when you take the old ceiling down. A small cheap borescope may be a good idea (these are now a thing!), or just taking down a test section.
Another question is whether you can tell if most of the sound you hear in the room below is transmitted through the joists when a foot lands in just the wrong place, or \"drumming\" caused by a foot landing in between joists, and transmitted through the air gap and retransmitted through the thin ceiling, or squeaking and other sounds caused by wood rubbing against wood under shifting load (which would be transmitted through joists to the thin ceiling and amplified by the ceiling acting as a membrane). Which type of sound you have determines which of the four \"elements of soundproofing \" is most important.", "timestamp": "1518196958"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926399875102", "anchor": "fb-926233049422_926399875102", "service": "fb", "text": "→ I think the diagram is showing an installation in new construction with engineered joists; a retrofit in an old building would look a bit different. Not really an error, just taken out of context.", "timestamp": "1518244505"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926418098582", "anchor": "fb-926233049422_926418098582", "service": "fb", "text": "→ Michael: I don't think it would look that different in an old building? I still have the joists, and room to install the drywall.", "timestamp": "1518264254"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926469335902", "anchor": "fb-926233049422_926469335902", "service": "fb", "text": "→ Jeff Kaufman The only difference would be whether the joists are \"engineered lumber\" (as shown in the drawing) or solid (as you actually have in your house). I was confused because I had thought that the joists as shown were an addition to the existing floor, attached to the bottom of the existing joists; I was simply wrong.
Diagonal bracing is a real thing. In some buildings it can be bidirectional and every foot or so; in others it can just be at the ends of the joists and unidirectional. I imagine that your house is closer to the latter, but I don't know what the common building practice in Somerville was. I've seen the first extreme in an early 19th century public building in Salem; I've seen the latter extreme in a late 19th century house in NYC.", "timestamp": "1518283868"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926470902762", "anchor": "fb-926233049422_926470902762", "service": "fb", "text": "→ Michael when I opened up the floor one above to put in a bathroom there wasn't any diagonal bracing", "timestamp": "1518284852"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926486765972", "anchor": "fb-926233049422_926486765972", "service": "fb", "text": "→ Putting the double drywall with green glue under the floor above, between the joists, is mainly for mass and damping, I'm pretty sure that stiffening is secondary. It doesn't matter if you just omit little sections, to work around any bracing that's in there anyway.", "timestamp": "1518291032"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926233049422&reply_comment_id=926550218812", "anchor": "fb-926233049422_926550218812", "service": "fb", "text": "→ Michael I was visualizing the \"every foot\" bracing that I encountered in Salem. For normal bracing, as you say, not such a big deal.", "timestamp": "1518315964"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926234875762", "anchor": "fb-926234875762", "service": "fb", "text": "If the floor above is an old wood floor, with gaps between the boards, and you accidentally pour a gallon of water on the floor, everything in that ceiling will soon dry out, except maybe the drywall below, where a wet piece can be cut out and replaced. But if there is a double layer of drywall right under the old wood floor, not accessible from above or below, I wonder whether it would dry out before getting moldy.", "timestamp": "1518196781"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926234875762&reply_comment_id=926235509492", "anchor": "fb-926234875762_926235509492", "service": "fb", "text": "→ Depends on how much of that special glue they use, and whether it's fully waterproof!", "timestamp": "1518197012"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926236407692", "anchor": "fb-926236407692", "service": "fb", "text": "If you use a rubber sound isolation mat on the existing floor, and then new flooring on top of the mat, then you can keep the new flooring disconnected from the walls, as well as disconnected from the existing floor. Floating floors use a rubbery barrier around the periphery, or just a gap around the periphery, then you hide that ugliness with a baseboard which is placed with a small gap above the new flooring. This is what I did when I finished my third floor room, but I just bought the sound isolation mat that the flooring manufacturer recommended, and installed the floating floor. I have no idea whether I actually got any soundproofing benefit out of doing it.", "timestamp": "1518197444"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926236407692&reply_comment_id=926238029442", "anchor": "fb-926236407692_926238029442", "service": "fb", "text": "→ Jeff, you are welcome to stop by and check the sound transmission through my third floor floor, which is the ceiling of my bedroom. This is a modern house, with some sort of flakeboard subflooring, on 2-by-something (2x10?) joists, with furring strips and drywall (1.2 inch drywall?) ceiling below. No insulation between the joists. It's about as bad as you could design for acoustics, if you were trying to design badly for acoustics. The acoustic underlayment under the floating floor above, is the only sound isolation portion of this construction. Stop by and check it out. (Message me privately to schedule.)", "timestamp": "1518198125"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926236407692&reply_comment_id=926248333792", "anchor": "fb-926236407692_926248333792", "service": "fb", "text": "→ What town are you in?", "timestamp": "1518202537"}, {"author": "Greg", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926236407692&reply_comment_id=926250569312", "anchor": "fb-926236407692_926250569312", "service": "fb", "text": "→ Yeah, this is a great idea. Assuming the padding is thick enough to absorb the impact and the new disconnected flooring is relatively stiff, this should provide a very good 'mute' on the hardwood underneath it.", "timestamp": "1518203477"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926236407692&reply_comment_id=926250684082", "anchor": "fb-926236407692_926250684082", "service": "fb", "text": "→ Lancaster. Take Rte 2 West, 8.5 miles past I-495, to Exit 36, and then I am 1/2 mile off the exit.", "timestamp": "1518203509"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926236407692&reply_comment_id=926250758932", "anchor": "fb-926236407692_926250758932", "service": "fb", "text": "→ You can also compare with second floor floor, and first floor ceiling, which is the same except that the second floor flooring is hardwood flooring directly on the same type of subfloor, rather than floating floor on underlayment on subfloor for the third floor floor.", "timestamp": "1518203598"}, {"author": "Will", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926418368042", "anchor": "fb-926418368042", "service": "fb", "text": "turn the loud thing down.....", "timestamp": "1518264528"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926418368042&reply_comment_id=926418407962", "anchor": "fb-926418368042_926418407962", "service": "fb", "text": "→ The loud thing is us and our kids walking around upstairs", "timestamp": "1518264569"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/925567762662?comment_id=926425369012", "anchor": "fb-926425369012", "service": "fb", "text": "Rock wool insulation is interesting, compared with fiberglass. I know little about it. I am only giving a link, and parroting a few of the claims I find in this link and elsewhere, you would need to evaluate this product further if you want to consider using it. Can be used for thermal insulation similar to fiberglass. Denser, so has better natural sound absorbing properties than fiberglass. Can be purchased with a sound barrier within the batt, as shown in this link, or just as a regular insulating batt. Said to be hydrophobic, so, unlike fiberglass, if water gets into the wall or floor where the batt is placed, it will dry out a lot faster than fiberglass. Unclear whether the sound barrier in this particular type of batt would interfere with moisture flow through the batt, would interfere with the ability to dry out if it gets wet. Obviously a rock wool batt is not a solution for your problem, but it may be part of a solution, maybe better than fiberglass *if* you are considering a system which would include a batt of insulation.
://www.lowes.com/.../ROCKWOOL-R-59-7-sq-ft.../3394032", "timestamp": "1518270521"}, {"author": "accidentalaquarist", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6gtpj", "anchor": "r-dy6gtpj", "service": "r", "text": "$1800 bedroom ceiling repair... wow hope the rent is going up to cover that.. lol\n\n
Looks good and probably sounds better. A 20dB drop is huge. \n", "timestamp": 1525034310}, {"author": "emersont49", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6h3hh", "anchor": "r-dy6h3hh", "service": "r", "text": "I built a small (90 sq ft) music room in the basement directly below our dining room. I use Roxul safe and sound between the 12\u201d joists. I put in two layers since it was cheap. I used hat channel but only one layer of 1/2\u201d drywall on the music room ceiling. I play electric guitar snd can jam out and no one above hears anything.\n", "timestamp": 1525034582}, {"author": "ElderScrolls", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6rt7p", "anchor": "r-dy6rt7p", "service": "r", "text": "→ I'm a huge safe n sound fan. Works amazing. I redid the downstairs with it a while ago. Just as an FYI to others, Roxul recommends leaving open air space in the joist and not filling completely with safe n sound. Allegedly it aids in the sound dampening. \n\n
That said though, I'm not sure which would actually be more effective. My gut tells me filling the cavity because it's more mass. \n", "timestamp": 1525046603}, {"author": "arizona-lad", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6i7nb", "anchor": "r-dy6i7nb", "service": "r", "text": "I am a bit confused with the graph. Finish+6, and finish+15. Why the difference?\n", "timestamp": 1525035717}, {"author": "cbr", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy9f3th", "anchor": "r-dy9f3th", "service": "r", "text": "→ Sorry, those are days since finish. The green glue takes some time to dry, so I was expecting it to get a bit better the longer I waited.\n", "timestamp": 1525172421}, {"author": "mrmackster", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6mrz4", "anchor": "r-dy6mrz4", "service": "r", "text": "That fiberglass insulation isn't meant for sound. Should have gone safe and sound or AFB.\n", "timestamp": 1525040578}, {"author": "ElderScrolls", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6rudi", "anchor": "r-dy6rudi", "service": "r", "text": "→ Any mass will help stop the echo chamber, but I can tell a WORLD of difference between my safe n sound walls and those with just fiberglass. So I agree with you 100 percent. \n", "timestamp": 1525046643}, {"author": "cbr", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy9fh8e", "anchor": "r-dy9fh8e", "service": "r", "text": "→ → Do those walls also have green glue, RSIC clips, and double drywall? My understanding is the extra mass from safe n sound (rock wool) wouldn't matter if you did.\n", "timestamp": 1525173148}, {"author": "badger-dude", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy87c3g", "anchor": "r-dy87c3g", "service": "r", "text": "→ Fiberglass does indeed help with sound, but not by much. When doing a decoupled system like the OP acoustic industry testing shows that it's a waste to pay more for the safe and sound. You will not be able to tell the difference when combined with double drywall and a clip and channel system. Basically in this application the "insulation" does a tiny amount of the sound reduction relative to the other solutions being applied.\n", "timestamp": 1525115854}, {"author": "mrmackster", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy89kh4", "anchor": "r-dy89kh4", "service": "r", "text": "→ → They already put insulation in there, so they spent money on that already. It's not in the price breakdown, so maybe they had it on hand already. The also sistered the joists to fit 6 inches of fiberglass in there so there is cost/work associated with that.\n\n
But even then, we talking about less than 200 dollars worth of materials for a project that you will never want to do again. \n", "timestamp": 1525117880}, {"author": "badger-dude", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy8ca52", "anchor": "r-dy8ca52", "service": "r", "text": "→ → → Yeah, I can't argue about just paying the extra $200 since it's a one time deal maybe. I just reread and noted as you said that they sistered to add depth for more insulation. Honestly though that was generally a waste. The sound experts I've consulted with say it's not worth going thicker than r-30 or 38, even if you have the space for it. Due to diminishing returns you are just wasting money and will not be able to hear any difference. \n", "timestamp": 1525120397}, {"author": "cbr", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy9fjvg", "anchor": "r-dy9fjvg", "service": "r", "text": "→ → \n
in this application the "insulation" does a tiny amount of the sound reduction relative to the other solutions being applied\n\n\n
I believe the insulation is primarily to reduce resonance in the cavity, and anything that takes up most of the cavity will work.\n", "timestamp": 1525173283}, {"author": "syrup_on_everything", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy6r33k", "anchor": "r-dy6r33k", "service": "r", "text": "that green crap is amazing. I'd say this might be overkill, but then again if they'res a hole anywhere, the sound will get through. Great freakin job dude!\n", "timestamp": 1525045707}, {"author": "badger-dude", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy88rdu", "anchor": "r-dy88rdu", "service": "r", "text": "Good job on the project and I like the testing results; much improvement. Just a couple helpful hint for others that may follow. I would recommend you install the insulation prior to the clip and channel system and be sure to use an "inset" style stapling installation rather than a "face" style stapling. You generally do not want your insulation hanging on the hat channel like is shown here. A bit of casual contact isn't a huge deal, but in the picture 6" batt, the insulation appears to be supported by the channel and friction rather than staples, in fact so much so that it might sag onto the drywall below. You want to avoid this if possible. The insulation should be tucked up into the joist bays (but not compressed) and not touching the rails or drywall if possible. One of the primary tenets of soundproofing is "decoupling" and having the contact like shown reduces the efficiency of the system since it adds contact area.\n\n
Also, there are diminishing returns for how much pink insulation you add. Generally beyond r30/38 you will not hear any difference and you are just wasting money. Really, the clips, channel, drywall and green glue are doing virtually all of the work in this configuration. Doing over I'd just fill the existing cavity and leave it alone. \n\n
It also might be a good idea to hire a structural eng to ensure that your particular joist configuration can handle all the added mass. The discontinuous pieces used here really won't add much strength and full span lumber would be preferred. However, it may be that his original joists could handle all the load, depending on wood quality and span, so what he did may just be above and beyond. He did indicate it was more for the insulation than strength. \n\n
Otherwise, the OP did a good job and appears to have solid results.\n", "timestamp": 1525117152}, {"author": "cbr", "source_link": "http://www.reddit.com/r/HomeImprovement/comments/8ftp32#dy9fe70", "anchor": "r-dy9fe70", "service": "r", "text": "→ \n
in the picture 6" batt, the insulation appears to be supported by the channel and friction rather than staples\n\n\n
We stapled the first 6" layer of insulation, and the second 6" layer is resting on the hat channel.\n\n\n
there are diminishing returns for how much pink insulation you add. Generally beyond r30/38 you will not hear any difference and you are just wasting money\n\n\n
I did see an improvement when adding the second layer of insulation (graph) but that was before I put in the ceiling.\n\n\n
I'd just fill the existing cavity and leave it alone\n\n\n
I also wanted to lower the resonating frequency by having a larger cavity depth.\n\n\n
The discontinuous pieces used here really won't add much strength and full span lumber would be preferred.\n\n\n
Yes, if I was doing this for strength I would sister with full length, and probably use 2x10s. This was mostly just for the height.\n", "timestamp": 1525172990}]}