Help me ID this insulation

I'm taking over this room, and current owner doesn't remember what material was used for the floors/ walls. Can somebody with some expertise in this area help me ID the insulation material pictured?? Thanks in advance! https://image.ibb.co/kDDuAa/IMG_0726.jpg

Good question! It doesn't look like it would have good acoustic properties, though. It looks something like "pink fluffy" fiberglass, but with that shiny surface it is probably not open-cell, at least on the surface. It almost looks like it has a plastic coating on it, or maybe some type of treatment that seals the surface. Perhaps it is some type of recycled product? Is there any type of marking on it at all? Even a bar-code, or a number of some type, or a logo? However, in addition to the questionable insulation, there's the issue of the badly done "floated" floor.... If I were you, I'd take that out, since it is not doing you any favors! In fact, it is likely making things worse, for both isolation and acoustics. That is an attempt to float a floor, but it is very misguided, and is not working. You could recover all those materials, and re-use them. Except for the rubber pads... those are no use. Throw them away. - Stuart -

Interesting, can you elaborate on that? He has owned space for several years and has never had any noise isolation issues (according to him), it's in a commercial building so I fear that tinkering with stuff like that could introduce some problems.

Interesting, can you elaborate on that?

Here's a thread that goes into the correct way to float a floor, why you probably don't even need to float it, and the many ways in which it can be floated incorrectly... viewtopic.php?f=2&t=8173 Also search the Internet for an excellent research paper put out by the equally excellent Canadian National Research Council, titled "Impact Sound Measurements on Floors Covered with Small Patches of Resilient Materials or Floating Assemblies", with the reference number "IRC-IR-802". Their research is excellent, but their administration is terrible: It used to be really simple to find all of their research papers on their own website, but they have made it increasingly difficult over the years, and today it is impossible. I have a letter I received from them recently after I questioned the lack of a method to find their documents, and the comment was basically "there is no way to search our data base any more, and we have no plans to fix that". So you'll have to search the rest of the internet to find that. They also have another very useful document, "Summary Report for Consortium on Fire Resistance and Sound Insulation of Floors: Sound Transmission and Impact Insulation Data", reference number IRC RR-169. There's also a document titled "The Effects of the Air Space on the Natural Frequency of an Acoustical Floating Floor", by Richard Sherren that should be a lot easier to find. In summary: The ONLY way to successfully float a floor is to have a massively heavy deck, supported on suitable resilient isolation mounts, such that the resonant frequency of the system as a whole is at least one octave lower than the lowest frequency that needs to be isolated. The air cavity is also part of that system, and needs to be sized correctly, and damped correctly. Slapping a plywood deck on a few 2x4's laid sideways on top of pads made of unknown rubber and spread around randomly, with unknown, non-acoustic insulation, will NOT float the floor. It's that simple. Think of it this way: If you put too much load on the "isolation mounts" (in this case, the rubber pads), then they "bottom out" They stop being resilient, and connect the deck directly to the sub-floor, passing through all sounds. On the other hand, if you don't put enough load on them, then they "top out": they are not yet resilient, and connect the deck directly to the sub-floor, passing through all sounds. For any given type of rubber, there is a range of loads that will cause it to actually be resilient and truly "float" the load. If your load is outside that range, then it will not float. That range is usually somewhere around 10% to 20% deflection, depending on the rubber. So if you load it so it compresses only 3%, or compresses 50%, then it will not float, and you get no isolation. Simple principles of physics and springs. So far so good! You figure "Well, I'll just calculate everything so that the load is just right". Great! But that won't work for a light-weight deck, such as a few layers of plywood. Think of this: Plywood weighs roughly 560 kg/m3, so if you make your floor from 2 layers of 12mm plywood, the load would be around 13 kg per square meter. Let's say you carefully choose rubber that will float between 10% and 16% deflection, and carefully calculate the load so that that it deflects (compresses) exactly 13% with the load of the floor on top of it, at 13 kg/m2. Perfect! It floats! ... until you stand on it.... Let's say you weigh 80 kg. Allowing for the way plywood spreads the load over a wider area, your 80 kg weight might spread over 2m2, meaning 40mg/m2. So you would increase the load from 13 kg/m2 up to 53 kg/m2 !! :shock: A factor of 400%! So with just you standing there, you increased the deflection of the rubber way beyond the limit of where it works... and your floor does not float. So you think "OK, well, then I'll design the floor so it floats only when people are standing on it, since it does not need to float when nobody is in the room!". Great! So you redesign your floor to float when the load is 53 kg/m2, and you make sure that there are enough people in the room to maintain that, and that's wonderful! ... Until you move in your desk with the console on top, that weighs 300kg together, and presses down on two small areas of the floor... At those points, with you standing there too, the load might be 100 kg/m2, 200% of the design load... so once again the rubber is squashed flat and does not float. If one part of the floor does not float, then the entire floor does not float. That "flanking path" through the floor under the loaded part negates the isolation of the rest of the floor, and NONE of the floor floats. In short, with a light-weight deck it is impossible to design a floor that will float under typical conditions, where there are people walking on it, equipment coming in and out, instruments coming in and out, things being moved around, etc. The ONLY way to float a floor is with a high-mass deck, and generally that is done with a concrete slab. The density of reinforced concrete is around 2400 kg/m3, so a slab 15cm thick weighs around 360kg/m2. In addition to the mass, concrete spreads the load over a much wider area than plywood, since it is far ore rigid. If you stand on it, you only change the load by maybe 10 kg/m2, increasing from 360 to 370... just a small fraction of the total load. Even if you move in that heavy console and desk, and a few more people too, and a bunch of equipment, and few crates of beer, and a dozen pizzas, the total load would increase to maybe 390 kg/m2... still just a very small change. So the floor continues to float, regardless of the changes in load. That's just one factor. The second factor is also relate to mass, but in a different way. All floating structures have a natural resonant frequency. If you play a tone that happens to coincide with that frequency, the floor will not isolate at all, and in fact can amplify the sound going through. So you need to "tune" the floor such that there is no possibility that any tone you play in there will coincide with the resonant frequency of the floor. There are two parameters you can change to tune it: the mass, and the air gap. If you increase either of those, then the frequency goes down. You want to get it as low as possible, so you need as much mass as possible. When you compare the mass of that concrete floor at 360 kg/m2, to the mass of the plywood at just 13 kg/m2, you can understand that the resonance of the concrete will be very low, way outside of the musical spectrum, while the resonance of the wood floor will be very much inside the spectrum. So the wood floor will not isolate low frequencies well, but the concrete certainly does. The other factor in there, is the size of the air gap. With a low-mass floor, you would need a large air gap to get the frequency down. But in the photo you showed, the air gap is small: the 2x4s are turned flat, which is incorrect and likely illegal for supporting a floor anyway, but even worse, the air gap is much thinner than it would be if they were correctly arranged, on edge. The smaller the air gap, the higher the resonance, and the lower the isolation. There are other reasons too, but in summary, a light weight floated floor will not work to isolate a studio. It cannot, since the laws of physics prevent it from doing so. Yes, I have seen many of those videos on YouTube where ignorant people or snake-oil salesmen demonstrate how they built a wonderful "isolation floor" with rubber pads, thin framing, and light-weight decks... but strangely, they never seem to provide any actual tests of how well the floor isolates after they are finished! I wonder why... No transmission loss tests, or impact noise tests, or even simple tests with a sound level meter. You would expect that if the floor really did work so well, they would boast about the test data, showing the "before" and "after" graphs, and proving that the floor made a wonderful difference... but they never do... Hmmmm... Strange, isn't it? :)

He has owned space for several years and has never had any noise isolation issues (according to him),

If you are in doubt, then do your own tests! Set up an acoustic drum kit and a bass guitar amp and an electric guitar amp on that floor, get some of your musician buddies to play their favorite songs as loud as they want, and measure the level in the room, and in adjacent rooms, especially the room directly below that one. Measure outside the window, in the passages, upstairs, rooms on either side.... Use a decent quality sound level meter, set to "C" weighting and "Slow" response. And also use your ears! If you can hear the music anywhere outside the room, especially in the room under that one, then the floor is not working. Listen especially for the bass guitar, the kick drum, and the snare. If that test shows that it is totally silent elsewhere in the building (and especially in the room below), and you cannot hear a thing with your ears, then I would be VERY surprised.... or I would conclude that the building already had more than enough isolation, due to the construction materials and techniques, such that the "floated" floor did not damage it too much... - Stuart -

Wow thank you for that thorough response! I'll check out the space again and follow your advice