Rockwool under Elastomer Floating FLoors - Which type?

[Paul Woodlock]

Rockwool under Elastomer Floating FLoors - Which type?


Greetings Experts :)


As I'm nearing building the formwork or my floating floor, I need to get the Rockwool to lay between the Sylomer Blocks.

how critical is this? Can I simply use the cheap attic insulation type * that comes in rolls ), or do I have to use the considerably more expensive 703/RW3 stuff.

Hoping the former!! :)


cheers in advance


Paul

[Paul Woodlock]

anyone? :)


Paul

[Eric.Desart]

Paul,

The same type as used in or planned for your walls (whatever that was).
Since the physical basics are similar, there's no reason to use something special or different here.

Eric

[Paul Woodlock]

Paul,

The same type as used in or planned for your walls (whatever that was).
Since the physical basics are similar, there's no reason to use something special or different here.

Eric

Thanks Eric. I was thinking of using the 'cheap stuff' for the walls and ceiling and using the RW3 for the acoustic treament. The surace area of the room ( Walls, ceiling, floor ) is about 83m2. This would cost me over £600 for even a 50mm layer of Rockwool RW3 all round.

However if using the denser rigid rockslab, like 703/RW3, instead of the cheap and fluffy stuff, is going to give an appreciable difference in Isolation then I might be worth incraesing the budget.

Am right in thinking, as my design is already a bomb shelter floated on 10Hz Elastomer, is the type of rockwool put in the air gap going to make all that much difference? On the other hand any extra dB of isolation you can get 'Late at night' must be a bonus.

but then I think this...... I've got 5 layers of Drywall, and now an air gap of 325mm. Two very thick, and tightly sealed doors, and superb Eric Desart (tm) Vent Silencers. And NO Windows. The airborne noise isolation should be excellent. And the structural sound transmission is taken care of by the elastomer floor. So is the type of 'air-gap rockwool gonna make much difference?


cheers

paul :)

[Bob]

Hi Paul:

Although I've been reading along, I can't do the math the way Eric can (don't know the formulas and wouldn't know what they meant even if I did), but here's a couple of things that you've probably already seen, which to my mind recommends the 'cheap stuff' :

a) http://www.kineticsnoise.com/architectu ... crete.html - this is isolation pads in a roll of insulation -- which implies to me that the insulation is not rigid because they can roll it for shipment.
b) For a decent photograph of the same thing, go to http://www.kineticsnoise.com/ and then on the left hand side move the mouse over "Architectural Sound Isolation".

[Paul Woodlock]

Hi Paul:

Although I've been reading along, I can't do the math the way Eric can (don't know the formulas and wouldn't know what they meant even if I did), but here's a couple of things that you've probably already seen, which to my mind recommends the 'cheap stuff' :

a) http://www.kineticsnoise.com/architectu ... crete.html - this is isolation pads in a roll of insulation -- which implies to me that the insulation is not rigid because they can roll it for shipment.
b) For a decent photograph of the same thing, go to http://www.kineticsnoise.com/ and then on the left hand side move the mouse over "Architectural Sound Isolation".

Greetings bob

I checked the sites.

I think you'e misunderstood what I'm talkign about.

The Loads from the floating room/floor are taken by the Elastomer blocks Only.

The Rockwool for the air gap between floors, walls and ceilings is there to dampen any resonances, and absorb a bit more sound. Purely airborne sound. While the Elastomer takes care of the structural isolation.

:)


Paul

[Bob]

Hi Paul:

I still think I understood what you are talking about.

I'm not suggesting you rush out and buy Kinetics RIM. Ignore the RIM blocks, and just look at the insulation in the pictures surrounding the little RIM squares. They took flexible insulation and cut out squares in the insulation where the blocks go, and in the case of RIM they glued the blocks to the insulation.

Are you not doing the same? Taking a blanket of insulation, and cutting out squares where the Solymer blocks go? So you'll have a little more 'air' damping around the Solymer 'structural' damping ?

I am just talking about the floor, between the concrete you already have down and the floating concrete floor that I think you've yet to pour. I'm not talking about the 1' of airspace around your room-in-a-room that you want to fill.

[avare]

I checked the sites.

I think you'e misunderstood what I'm talkign about.

The Loads from the floating room/floor are taken by the Elastomer blocks Only.

The Rockwool for the air gap between floors, walls and ceilings is there to dampen any resonances, and absorb a bit more sound. Purely airborne sound. While the Elastomer takes care of the structural isolation.

First of all, thanks for your diary of the build of your studio. A great documentation of the process: technically, practically and emotionally.

I read your initial post in this thread and did not respond because I felt the information I had was too vague to answer properly. From what I am reading now, this vagueness is causing the problem right now. I tried to search back and get clear answers to some questions and came up with no clear information. Unfortunately with technical communication details and specifics are critical.

You make several references to Sylomer. I could not find any posts detailing what exactly it is and how you are using it. I checked the web for sylomer and found references to sheet to be laid continuously under floors, blocks, of material, and variations thereof. You wrote that you purchased app.2 m^2 of the material and that it is 50 mm thick.

I am assuming, as I think all the other people responding in this thread, that you are going to cut the Salome material into small blocks, maybe 50 x 50 mm and then space them regularly in a some form of pattern, maybe square with 600 mm between the centers of the Salome pads. On top of the pads will put the MDF, or whatever you will use for the concrete form.

Your question is then what type of absorbent you should/can use between the spaced Salome pads.

If the above two paragraphs are correct, then all the answers you have received are correct. You can use regular insulation. Using the same material as your other cavity absorption would be better.

The product that Bob described (Kinetics Rimfloor) is exactly a commercial implementation of this design. Kinetics pre glues the pads (same as your Salome) to the insulation. They use 3.0 pcf material. The mitigating factor is that you are doing this on a basement floor, while the Rimfloor is also used on ceiling/floor barriers.

Am right in thinking, as my design is already a bomb shelter floated on 10Hz Elastomer, is the type of rockwool put in the air gap going to make all that much difference? On the other hand any extra dB of isolation you can get 'Late at night' must be a bonus.

but then I think this...... I've got 5 layers of Drywall, and now an air gap of 325mm. Two very thick, and tightly sealed doors, and superb Eric Desart (tm) Vent Silencers. And NO Windows. The airborne noise isolation should be excellent. And the structural sound transmission is taken care of by the elastomer floor. So is the type of 'air-gap rockwool gonna make much difference?

Only you can answer that question. If you feel that the construction is already "bomb shelter" why do you think that it is necessary to float the floor. For whatever reason you obviously chose to do that. I know of at least one studio designer/builder who will not recommend any construction that has not been tested or at lest well proven in practice. The use of 3.0 pcf material in the space of the floating is of the latter type.

Consider this: with all the the and expense and time you are going through to float the floor, why not do it right? You can save some money by going to the less dense material, but is the potential for creating the weakest link worth it?

If you are on a significant budget restriction consider putting no insulation at instead of going halfway. Floating floors of the raised concrete type have no insulation by design.


Good luck and keep the build diary going!

[Eric.Desart]

Hi All,

This whole construction is designed already into detail.
Andre the reason you can't find it is that 90% of the Paul's studio saga was covered by the previous group that was deleted by Yahoo.

Paul is working in exact the right direction as planned and intended.
So the only question is which wool to use in the cavities (walls, flooting floor).

Paul:
Resonances are powerful.
I think it should be stupid in function of price versus your concept now to save a minor bit of money.

If you use wool go for 40 to 45 kg/m3. If you go for glassfiber go for ca 28 to 32 kg/m3.
I shouldn't go lower, unless you do a filling with blankets a bit as the RSIC-1 walls.

Kind regards
Eric

[Paul Woodlock]

Hi Paul:

I still think I understood what you are talking about.

I'm not suggesting you rush out and buy Kinetics RIM. Ignore the RIM blocks, and just look at the insulation in the pictures surrounding the little RIM squares. They took flexible insulation and cut out squares in the insulation where the blocks go, and in the case of RIM they glued the blocks to the insulation.

Are you not doing the same? Taking a blanket of insulation, and cutting out squares where the Solymer blocks go? So you'll have a little more 'air' damping around the Solymer 'structural' damping ?

I am just talking about the floor, between the concrete you already have down and the floating concrete floor that I think you've yet to pour. I'm not talking about the 1' of airspace around your room-in-a-room that you want to fill.

Ah, OK Sorry :)

We *are* on the same page :)


Paul

[Paul Woodlock]

Hi All,

This whole construction is designed already into detail.
Andre the reason you can't find it is that 90% of the Paul's studio saga was covered by the previous group that was deleted by Yahoo.

Paul is working in exact the right direction as planned and intended.
So the only question is which wool to use in the cavities (walls, flooting floor).

Paul:
Resonances are powerful.
I think it should be stupid in function of price versus your concept now to save a minor bit of money.

If you use wool go for 40 to 45 kg/m3. If you go for glassfiber go for ca 28 to 32 kg/m3.
I shouldn't go lower, unless you do a filling with blankets a bit as the RSIC-1 walls.

Kind regards
Eric

Thanks Eric :)


I can get Rockwool RW45 = 45Kg/m3 @ 50mm thick.

This would cost me just over £400 ( before haggling! ) for the total room surface area.

Obviously for the floor it's going to have to be 50mm thick

Would 50mm thick RW45 be suitable for the walls and ceiling too?

Avare:

I'm pleased you're enjoying the Diary. :) As Eric says, sadly most of the discussions determining the design werE lost When yahoo deleted the acoustIcs group iN january. thE malicious culpRit is known and will one day pay for their actions.

Only you can answer that question. If you feel that the construction is already "bomb shelter" why do you think that it is necessary to float the floor. For whatever reason you obviously chose to do that.

Because of the 'bomb shelter walls and ceilings, the floor ended up being the weak point in the sytem. you may find it useful to re-read the intial post again in the Diary. I explained as much as Icould to bring the Diary upto date there. :)

Cheers :)

Paul

[Eric.Desart]

I can get Rockwool RW45 = 45Kg/m3 @ 50mm thick.

This would cost me just over £400 ( before haggling! ) for the total room surface area.

Obviously for the floor it's going to have to be 50mm thick

Would 50mm thick RW45 be suitable for the walls and ceiling too?
Paul

Yes :):)
But If I were you I should compare prices with the Isover glassfiber.
Maybe an unexpected diner is saved with the wife:)

Eric

[Bob]

Obviously there's only 2" around the floor's solymer blocks to put insulation, if the blocks are 2" tall.

Are you saying that in the 1' (325mm) air space in the walls, you're only going to put 2" (50mm) of RW45 (45kg/m3 = 3pcf)?

[Paul Woodlock]

Obviously there's only 2" around the floor's solymer blocks to put insulation, if the blocks are 2" tall.

Are you saying that in the 1' (325mm) air space in the walls, you're only going to put 2" (50mm) of RW45 (45kg/m3 = 3pcf)?

Greetings Bob

I'm not sure yet. I'm asking if this is all that's required. I certainly can't afford to fill the air gaps completely :) It would cost thousands of shekels.

However I do plan to leave an air gap BOTH sides of the rockwool in the airgap.

For example, I'm using 6" studs, so I could fit in 2" of rockwool between them, and still have a 4" airgap between the rockwool and the drywall. I'm assuming any rockwool right up against the drywall, on't have as much effect.

I'm normally up for bunging in as much as possible, in a belt and braces approach. but this floor has cost me so much, I need to watch the budget a lot more carefully now.


:)


Paul

[Paul Woodlock]

I can get Rockwool RW45 = 45Kg/m3 @ 50mm thick.

This would cost me just over £400 ( before haggling! ) for the total room surface area.

Obviously for the floor it's going to have to be 50mm thick

Would 50mm thick RW45 be suitable for the walls and ceiling too?
Paul

Yes :):)
But If I were you I should compare prices with the Isover glassfiber.
Maybe an unexpected diner is saved with the wife:)

Eric

"isover" ?

Was that a typo, or a certain type of glassfibre? I know nothhing about glassfibre slabs. Does it come in 'stiff' boards like 703/RWx ?

If it's cheaper, and could also be used for acosutic treatment, I think I'd better learn :)


Eric , AM I right in thinking the best place to 'insert' the glass/rock in the airgap between walls, is by leaving an airgap either side of the absoprtion material.



Paul

[Paul Woodlock]

Greetings Eric.

OK I found the Isover Webpage :)

I coudln't find the density of the Isowool Plain slabs, but it does come in 50mm thick slabs 1200x600mm (same as RWA45 )

I'll Email the company and ask what density it is.


Eric , AM I right in thinking the best place to 'insert' the glass/rock in the airgap between walls, is by leaving an airgap either side of the absoprtion material.

Hope ya well

Paul :)

[Bob]

If you get absorbtion coefficients please let me know.

[Paul Woodlock]

If you get absorbtion coefficients please let me know.

http://www.isowool.com/pdfs/PlainSlabs.pdf :)

goto http://www.isowool.com/architects/index.html

Click on Products,and look at the pdf's

Paul