HUB Studio

[Hub]

I looked through sketchup again and found the field of view tab. It was set to about 100! this is why it looked so distorted and why parallel projection looked the best. I have set it to 50 now which looks more normal. I think this may relate to a 50mm camera lens(not sure if I am correct) which I have heard is more like what we see as humans.

[Hub]

Another thing I just noticed: I hadn't picked up on it before, due to the distorted viewpoint of parallel projection, but it seems like you are planning to float your CR floor? That's not good. A raised or floated floor done the way you show it will lead to major resonant issues. The floor will act either as a drum head, or as some form of resonant trap, depending on the details. You don't want either of this for a studio floor, and especially not under a drum kit!

- Stuart -

What would you suggest to put on the existing plywood floor if we don't put a floating floor on top of it? We are trying to isolate the sound coming from downstairs in the shop and visa versa.

Studio01 23.03.jpg

The existing floor is as follows:

- 19mm plywood floor(this is the existing floor)
- 250mm x 45mm joists(400 centers with insulation in between)
- 30mm plasterboard(this is the shop ceiling)

We were designing the floating floor in the LR to be 90mm high to help with cable ducting underneath and 50mm in the CR.

[Soundman2020]

I looked through sketchup again and found the field of view tab. It was set to about 100!

No wonder it looked distorted!!!! I think the standard setting is something like 35 or 40, but I normally use around 45 as it seems to be a good balance between reality and being able to move around without getting the camera stuck inside walls and things. And sometimes I go to the other extreme, around 10, when I need to get in really close for some reason.

Glad you found that! It's a lot easier to work with realistic perspective!

- Stuart -

[Soundman2020]

What would you suggest to put on the existing plywood floor if we don't put a floating floor on top of it? We are trying to isolate the sound coming from downstairs in the shop and visa versa.

The best way to do that would be from below: re-hang the ceiling of that shop below you on resilient channel. Two layers of 5/8" (16mm) drywall on resilient channel, with plenty of insulation in the cavity and good seals all around, would work wonders. Then another couple of layers of plywood on your floor, to add some more mass there, and a rum riser, to keep impact noise out of your floor, should be enough to drastically reduce transmission between the two rooms.

However, and this is a big question: is that floor structure capable of supporting all this weight? Only a structural engineer can answer that. The entire building structure, including the floor, was designed for a certain live load and a certain dead load, and adding all this weight to the floor might very well take it beyond its design limits. So to make sure that it is safe to build anything at all on top of that floor, you need the written opinion of a qualified structural engineer. He will inspect what you have, do the calculations, and then tell you how much extra load (if any) you can add there safely. Without that, you should not do any modifications at all.

- Stuart -

[Hub]

, and a rum riser, to keep impact noise out of your floor

What is a rum riser?

Also downstairs already has metal top hats (are these resilient channel?) So if we just take up the existing studio ply floor and pack more insulation and re seal and apply 2 layers of 18mm ply then the rum riser( ) we are back on track.

By the way thanks for all your amazing help

[Soundman2020]

What is a rum riser?

Ummm... that's an embarrassing typo! What I get for relying on spelling-checker without checking too closely....

That should have been a DRUM riser, not a rum riser...

A drum riser is a platform for your drums to sit on, and it decouples the drum kit from the floor, so the impact vibrations are not transmitted from the drum kit into the floor. It only needs to be as big as the drum kit. You can do something similar (on a smaller scale) for bass cabs, and anything else that might transmit vibration into the floor.

Also downstairs already has metal top hats (are these resilient channel?)

Nope. That's hat channel. It looks similar, but is actually very different, from the point of view of acoustics. Hat channel does not decouple, but resilient channel does. So it has to be proper resilient, channel.

The other alternative is to use hat channel along with RSIC clips, which also decouple. But hat channel by itself is no use, sad to say.

The concept is simple: there has to be a resilient (as in "rubbery" or "bouncy") disconnect between the drywall and the actual building structure, so that the drywall "leaf" down there and the flooring "leaf" up where you are, are not directly joined through a hard mechanical connection. This is called "decoupling", breaking the solid path that sound can travel along. And here again, that resilient decoupling thing has to be correctly designed for the job: you can't just through in any kind of metal channel, or any type of rubber: only things that are specifically designed for the purpose of this type of acoustic decoupling.

So you could probably fix that either by installing RSIC clips between the hat channel and the joists, or by replacing the hat channel with resilient channel. (But not both).


- Stuart -

[Hub]

Unfortunately we cannot go under in the shop to change the fire rated ceiling so we have to come up with another solution. We can start taking up the original plywood floor and inspect the joists and insulation above the shop and seal up where we can and stuff more insulation(and prove there is enough). Is there a way to decouple the floor above?

[Soundman2020]

Unfortunately, I have to be the bearer of bad tidings here: There isn't really much you can do from above, apart from actually floating a new floor. But as you saw in the link I gave you about that, floating a floor on an upper story in a building is not a simple proposition at all, and certainly not cheap, even assuming that the structure underneath has the ability to support the large amount of mass that you need. All you can really do is to add mass to the existing floor, by putting down several layers of thick MDF or OSB, but then you are limited by Mass Law, which is a law of physics that is not very friendly: it says that if you double the mass, then you get a 6 dB increase in isolation. So if you start withe one layer of OSB, then add as econd layer you get 6 dB more. Add another TWO layers for the next 6 dB, then another FOUR layers for the next 6 dB, etc. Not fun. With mass law alone, you run out of structural integrity (and money!) long before you get to reasonable levels of isolation. That's why mass alone is not the best way of isolating: Mass + mass decoupled by a resilient "spring" is the way to go for high levels of isolation. It's a whole different ball game. In your case, it's very easy to do from below, but not easy at all to do from above.

Is there no way at all that you can do this from below? Whoever owns that place downstairs surely would not mind you guys going in and giving them a brand new ceiling installation, for free! Especially if they will benefit from the increased isolation just as much as you will. Maybe you could talk to them, and see if they are open to the idea? If someone came to be and offered to replace and re-paint my ceiling for free, and it would even make things quieter to boot, I think I'd be inclined to listen...

Failing that, you don't have a lot of choices: floating your floor is the only real solution.

You might also find these helpful:

http://archive.nrc-cnrc.gc.ca/obj/irc/d ... /ir802.pdf

http://archive.nrc-cnrc.gc.ca/obj/irc/d ... /ir811.pdf
(that one is probably the most comprehensive study on floor isolation systems ever done, that is available publicly).

http://archive.nrc-cnrc.gc.ca/obj/irc/d ... /ir766.pdf
(also excellent)

Not exactly light reading, but very informative, and very pertinent to what you guys are trying to do, I think. Those are pretty much the definitive studies on the subject of floor isolation.

The only other thing thing that might work to a certain extent, is the "drum riser" concept but extended to the entire floor: cover the entire floor with 2" of OC-703, then put two layers of 19mm MDF or plywood on top, screwed and glued, but carefully cut so that it does not touch the walls: Leave a gap of about 5mm all around the edge, and fill that with acoustic caulk. That's not a proper floated floor, just a partly decoupled, partly damped floor that MIGHT work for you. At least it will help with the impact noise, even though it won't isolate fully.

Sorry I can't give you any better news than that, but the universe is created in such a way that the laws of how it works are immutable, and no amount of hoping or frustration can change that: The laws of physics are what they are, and their are no magical materials that can bypass those laws.

But regardless of what you do, I'd still get a structural engineer to take a look at that floor, and confirm how much extra load you can put on it safely. Your studio is going to weigh a huge amount, considering the level of isolation you are seeking, so you MUST make sure that the building structure can handle that, and if not then beef it up sufficiently that it can.


- Stuart -

[Hub]

Thanks for the reply Stuart.

We lifted part of the plywood floor under the live room to confirm the construction and there was about 3sq meters of floor that did not have insulation. Also there were a few gaps and a very large one(400mm x 500mm) hole that extended all the way to the bottom floor in between their internal plasterboard stud wall and outer brick wall which was letting in some noise. We sealed this up and are packing inside with insulation.

Floor repair.JPG

Just a thought, when we put the floor back could we put acoustic caulk (or neoprene caulk) on the joists so we can partly decouple? It got me thinking would it help if we pulled up all the floor and did this and cut 5mm away from the perimeter walls and add the caulk?

We have a structural engineer looking at all the loads at the moment and are waiting for his reply.

If we went with your suggestion of the 2" of OC-703, then put two layers of 19mm MDF or plywood on top etc, would we then build the stud walls for the CR and LR directly on top of this or would we put neoprene pads in between?

If we placed a layer of rubber between the last layers of ply would this add extra decoupling and STL?

[Hub]

We are considering the option of using the OC730 rigid 50mm thick fiberglass board on top of our existing floor followed by 2 layers of 18mm ply and then the framework on top of that.
Will the fiberglass compress more at the point where the inner frame of the CR & LR or will the fact that the 36mm of plywood in between will more evenly distribute the weight?

[Soundman2020]

We are considering the option of using the OC730 rigid 50mm thick fiberglass board on top of our existing floor followed by 2 layers of 18mm ply and then the framework on top of that.

OK, that's the "drum riser" concept, adapted to a floor. It will help to a certain extent, for sure, but won't isolate the way a properly done floor would. Still, it is certainly a good option for you guys.

Will the fiberglass compress more at the point where the inner frame of the CR & LR or will the fact that the 36mm of plywood in between will more evenly distribute the weight?

You cannot rest the walls on a floor built like that! That would be dangerous. That method is just for the floor alone, no structure on top of it. It is not meant to be load-bearing. The walls will still have to rest on the real subfloor, not on top of that "drum riser" deck.

- Stuart -

[Hub]

Question 1

If we were to lift the rest of the existing plywood floor (as we have done in the live room area), could we benefit from using 2 beads of neoprene sealant along the top edge of all the bearers before we put the existing floor back down and not screw this but allow the sealant to set, also use neoprene sealant between the floor and the walls so there is no mechanical connection and by this will it result in extra DE-coupling? The other way we could do this is by using the neoprene striping which comes in 10m rolls at 50mm wide x 3mm thick and glue this down to the bearers before we put the floor back on.

LR 1.JPG

LR 2.JPG

Question 2

If we use the OC730 rigid 50mm thick fiberglass on top of the existing plywood floor then we add the 2 x layers of 18mm plywood on top of that(stagger the layers, glue together and screw only the 2 layers together with screws spaced at 300 centers) do we then cut the floor about 5mm from the CR & LR finished internal walls and fill the gap with neoprene sealant(as was mentioned before)?


Question 3

When we put the CR & LR frames on top of the existing floor do we also place some neoprene underneath this, say either pads or we can get 75mm wide x 3mm thick under this?
The sizes the strips come in are 50mm wide x - 1.5mm thick
- 3.0mm thick
- 4.5mm thick
- 6.0mm thick
- 9.0mm thick

I know there is a lot of information on this site and one fellow said he paid to get some tests done on some material to see how much compression it took under a certain load so he could work out how to space the pads according to the weight calculated above based on compression performance, but if we use the strip this would surely help the de-coupling without having to pay for tests. I know it would probably be a better result if we got the tests but surely it would be a help and wouldn't be a complete failure if we used neoprene stripping.

It would be great if there were pads that you could buy in packs that just simply had the compression information on the pack so you could easily make the spacing calculations.

[Soundman2020]

could we benefit from using 2 beads of neoprene sealant along the top edge of all the bearers before we put the existing floor back down and not screw this but allow the sealant to set, also use neoprene sealant between the floor and the walls so there is no mechanical connection and by this will it result in extra DE-coupling?

I'm not sure what you mean by "neoprene sealant", but the only way that MIGHT work is if you do the necessary testing and calculating, and prove that your full loaded floor will deflect the sealant just the right amount to cause it to float. That amount depends on the characteristics of the sealant itself, so you'll have to check with the manufacturer to find out what the optimum deflection is for maximum resilience, but you'll probably find that it is somewhere in the region of 10% to 20%, give or take a bit. If you can guarantee that your entire sealant beads will all deflect to the correct range when the floor is fully loaded, then that might work. However, the chances are slim: If you overload the floor such that the sealant deflects too much, then it will flank and you will not get any isolation. And if you don't load it enough, it will also flank, and you won't get any isolation. So you'll have to calculate and experiment very carefully, until you are certain that you can lay the beads accurately enough, and load the floor precisely enough, and do that all without accidentally creating any flanking paths....

The other way we could do this is by using the neoprene striping which comes in 10m rolls at 50mm wide x 3mm thick and glue this down to the bearers before we put the floor back on.

Once again, you'd have to check with the manufacturer to find out what the correct deflection is for optimum resilience, find out what loading causes that amount of deflection, then calculate your floor loading and neoprene area just right to ensure that it really does float. Same as above; too much load flanks, and not enough load flanks.

I know there is a lot of information on this site and one fellow said he paid to get some tests done on some material to see how much compression it took under a certain load so he could work out how to space the pads according to the weight calculated above based on compression performance,

Yes, that is indeed the correct way of going about things.

but if we use the strip this would surely help the de-coupling without having to pay for tests. I know it would probably be a better result if we got the tests but surely it would be a help and wouldn't be a complete failure if we used neoprene stripping.

It will only work if you do the necessary calculations and load the floor suitably to get the correct deflection at all points. That means providing more pad area under heavy areas of the floor (EG, the desk, racks, sofa, chairs) and much less under non-loaded areas (open spaces where nobody ever walks). You have to take all of those into account when you do the calculations, you need to know the weight of everything, and figure out how much area of pad you need under each floor region, to cause it to float correctly. It's complex: Not for the feint of heart....

Your chances of it working out purely by sheer luck are somewhere around zero...

It would be great if there were pads that you could buy in packs that just simply had the compression information on the pack so you could easily make the spacing calculations.

There are, but you still need to do the calculations, and that's where the problems come in...

- Stuart -

[Hub]

Hi there

We are just about to restart our studio after deciding to move the location to the opposite side of the stage. This means the original studio plan is now mirror reverse. We decided this since the downstairs business was causing too many engineering complications and the other side is over dirt.

I am doing calculations on the load of the walls on the floor. We are floating the walls and having a separate floating floor on rigid 50mm fibreglass with 2 x 18mm ply flooring on top. The plywood will fall short of the walls by 5mm and we will fill with sealant.

I have a pad of 70mm x 50mm which I have tested under load. The compression is as follows:

Original thickness - 14.75mm
25kg load - 14.2mm
55kg load - 13.6mm
105kg load - 12.5
155kg load - 11.2
185kg load - 11.2

Since the approximate load on the bottom of the frame around the entire perimeter is 250kg per lineal meter( this is including studs, gyprock, insulation, joists, beams, room diffusers)
I am thinking of placing 3 pads every metre. This would compress my pads to about 13mm which equates to about 12% compression. The product seems to bottom out at about 25% compression at 185kg.

Any comments appreciated.

[Hub]

Here are some images of the new plans for the right side of the stage studio.

Plan.jpg

Elevation.jpg

Below is an image of the studio in context to the stage.

Stage & Studio.jpg

And here are some more images

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