Plasterboard or Render?

[Oliver21]

I'm converting my internal garage into a studio. It will be one room for rehearsal and recording.

The two external walls are double skin lightweight thermalite blocks with a 4" gap filled with fibreglass.

Sould I dryline the wall or render. Obviously I'm trying to acheive maximum isolation from outside so do I add mass to the inner skin or dryline with plasterboard? I don't really want to start using resilient channel as this will bring the room width down to unacceptable levels.

I'm quite realistic about how much isloation I'm going to get so as a general rule does anyone know whether adding an inch of cement render to the inner skin would offer more or less isolation than a half inch (12mm) drylined pasterboard.

Many thanks

O

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resilient channel is 15mm deep.

add 2 layers of acoustic plasterboard , better yet 3, , that's a total of between 42.5-61.5mm on each wall. + a few mm for internal plaster skim.

you lose no more than 3 inches off each wall 6 inches total dimension on length and width. 3inches height.... assuming the roof can take it.

(well the door end might be different )

the question you need to ask yourself, is whether you want it to work or not.

your current route... not terribly effective.

direct mounted resilient channel route = a shed load better

battened and insulated mounted resilient channel.... better still . lose about 8.5 to 9 inches of total width if done on bare minimum.... 30 mm wall fixed battens, using high density 30mm mineral slab insulation... (such as that stuff from wickes)

independent stud route, a LOT better still, BUT as you say, would lose too much space.

all of this presupposes that the materials are correctly installed...

[Oliver21]

Hmm... so are you saying that the difference would be negligable?

[Ten21]

Idris hit on the main point here

Your door and your ceiling it doesn't matter about the spec of your garage walls if all the sound leakage is through your door and ceiling. I would consider beefing up these areas before you even start on the inside.

As for plasterboard vs render, imho plasterboard every time. It provides damped mass whereas render is too rigid.

As for "acoustic" plasterboard I have never actually used it (so what do I know) but I have to say that unless it has some uniquely different physical quality then the use of the word "acoustic" in front of a board that from what I can gather is merely twice as thick and heavy as standard plasterboard should be taken with a pinch of salt. In fairness to the manufacturers I'm sure they probably mean when used as part of a properly designed acoustic system, in the absence of which I would alternatively go for 2 layers of standard plasterboard with the added benefit of being able to stagger your joints. Let alone the ease of handling

From first hand experience I know how hard it is to clad even even with standard p/b (all 250 sheets of them!) so I wouldn't fancy handling 1" boards.

I'd go 2x2 batten RW3 50mm rockwool, but DO sort out the door and inner ceiling first

Good luck

[. . . Delete This User . . .]

acoustic plasterboard has a different core density and structure to ordinary plasterboard, and yes it's worth using.

they aren't 1 inch boards...

std thicknesses are 12.5 mm and 15mm

all the major plasterboard manufacturers make them, and they're all much the same thing,
just with different names

dBCheck(LaFarge), Soundbloc(British Gypsum), Soundshield (knauf) are all equivalent products.

and yes i use them a lot.
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[Jucky Joe]

Hi All, i am about to fit a woodburner, when it is in place i will have 4ins clearance on each side, i intend to fit slate or quarry tiles to the side walls, but would it be wise to use plasterboard and plaster and then tiles or cement render and then tiles on that.

[Guest]

Hi All, i am about to fit a woodburner, when it is in place i will have 4ins clearance on each side, i intend to fit slate or quarry tiles to the side walls, but would it be wise to use plasterboard and plaster and then tiles or cement render and then tiles on that.

Hi Jucky Joe, welcome to the SOS forum.

It would be appreciated, if you have questions about things unrelated to the original post, if you could please start a new thread. Do this rather than posting on someone else's thread, since some of our members may consider this 'hijacking', and will take offence particularly if you are doing it across multiple threads in multiple boards...

Also, I'm not sure the question you asked is an appropriate question to ask on a music technology/recording website, as it doesn't relate to anything discussed on these forums. You might be best trying a well-known search engine!

[. . . Delete This User . . .]

in terms purely of fire safety, cement render and tiles on it.... how that may relate to your sound proofing requirements i couldn't say without knowledge of the site.

(and the thicker the tiles, the better..... )

[Ten21]

acoustic plasterboard has a different core density and structure to ordinary plasterboard, and yes it's worth using.

they aren't 1 inch boards...

std thicknesses are 12.5 mm and 15mm

all the major plasterboard manufacturers make them, and they're all much the same thing,
just with different names

dBCheck(LaFarge), Soundbloc(British Gypsum), Soundshield (knauf) are all equivalent products.

and yes i use them a lot.
\

Hi Idris

Thanks for the update. I guess I'll give them a try, I'm planning a little expansion next year. What's it like for fixing overhead ie weight-wise and screws pulling through etc.

Cheers

Sean

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you should always use a panel lift to put sheet materials on the ceiling, that way you can place them accurately, and have them fully supported while being fixed, with minimal effort.

typically slightly more robust than domestic plasterboard. use proper drywall flush finishing screw driver heads.... ceiling panels fixed at 100mm centres along 250mm spaced lines. with a consistent 25mm lateral offset per layer. to avoid hitting the screw of the previous layer with the next one...

using proper drywall screws...

[Ten21]

Hi Idris

Thanks for that

you should always use a panel lift to put sheet materials on the ceiling, that way you can place them accurately, and have them fully supported while being fixed, with minimal effort.

typically slightly more robust than domestic plasterboard. use proper drywall flush finishing screw driver heads.... ceiling panels fixed at 100mm centres along 250mm spaced lines. with a consistent 25mm lateral offset per layer. to avoid hitting the screw of the previous layer with the next one...

using proper drywall screws...

[James Perrett]

you should always use a panel lift to put sheet materials on the ceiling,

Thanks for the heads up on the panel lift. It came just as I was wondering how I was going to fix the ceilings in the new studio.

James.

[Oliver21]

Alright I'l put it another way. All things being equal ie. the door and windows being up to the standard of the walls is there anything in theory to choose between render and plasterboard? I'm looking for figures here if possible...

[James Perrett]

Without some kind of flexible layer or resilient channel, the improvement will be negligible and not worth bothering about.

James.

[Oliver21]

resilient channel is 15mm deep.

add 2 layers of acoustic plasterboard , better yet 3, , that's a total of between 42.5-61.5mm on each wall. + a few mm for internal plaster skim.

you lose no more than 3 inches off each wall 6 inches total dimension on length and width. 3inches height.... assuming the roof can take it.

(well the door end might be different )

the question you need to ask yourself, is whether you want it to work or not.

your current route... not terribly effective.

direct mounted resilient channel route = a shed load better

battened and insulated mounted resilient channel.... better still . lose about 8.5 to 9 inches of total width if done on bare minimum.... 30 mm wall fixed battens, using high density 30mm mineral slab insulation... (such as that stuff from wickes)

independent stud route, a LOT better still, BUT as you say, would lose too much space.

all of this presupposes that the materials are correctly installed...

What is battened and insulated mounted resilient channel? Do you fix the 30mm slab to the wall then the battens to this then the res channel to that? 9" might be pushing it but maybe i could live with 6"

Cheers Chaps

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fix batten to wall, at 600mm centres, fill between with 30mm high density rockwool, then fix resilient channel across batten , at 300mm centres, and fix 3 layers of plasterboard (19,12.5,15) to that, with green glue between each layer of plasterboard.

MUCH more effective than what you had planned, and the depth, per wall side , you lose about 4 inches , so 8 inches total across the room (2 sides to a room width) !

not cheap, but it works.... and that's kind of what matters

not quite as effective as a fully freestanding arrangement, but a reasonable compromise.

[Oliver21]

thanks Idris. Presumably the denser the rockwool (ie 140kgm3) the better....?

Do you still need to screw the plasterboards even though your green gluing them?

Is green glue really worth the extra considerable cost?

How do you attach the rockwool to the wall?

Sorry for all the q's

[. . . Delete This User . . .]

yeah, the 30mm high density stuff from Wickes (as used by paul and hugh in their studio SOS DIY bass traps) is ideal.

yes you need to screw the plasterboard, green glue is not a glue..... it's a damping compound, and hell yes it's worth the extra cost....

note that you MUST use the right length screws for each layer, and not allow them to dig in to the board, use a proper flush finishing drywall screwdriver bit to do this..... it has a ring around the edge that prevents the screwdriver from going too far.

the rockwool, if you do it right, will fit neatly , tight, between the battens, and be held in by friction, until you put the resilient channel across, then it will be held in by both friction and resilient channel

and yes, i do this, at least in part, for a living.

[Oliver21]

thats great Idris thanks

[Oliver21]

Have just found these on line http://www.midlandlead.co.uk/products/boards.html?gclid=CIfZ2p-T1qkCFcNP4Qod4DTKMw

Working on the principle that adding mass to the wall will improve isolation (and that I'm trying to save space in my room) would battens, rockwool resilient channel with a layer of lead lined board be the "non-stud partition wall" dream scenario?

These code8 3.55mm lead lined boards are 600mmx 2400mm and 70kg each but quite pricey at £177 each plus VAT.

This is 140 kg per 8x4 at 12.5mm thick as opposed to 109kg per 8x4 at over 100mm thick. Quite a difference!

Now the price difference:

Both scenarios use batten, rockwool and resilient channel so this would be the same for both.

Acoustic plasterboard with green glue approx £50 for 8'x4'
Lead lined plasterboard approx £425 for 8'x4'

Very, very scary indeed, but could be worth it i suppose

[James Perrett]

You will save only 34mm of plasterboard as you still need the battens, rockwool and resilient channel. You will probably need more resilient channel as they will be have to be closer together to handle the extra weight.

James.

[Oliver21]

That's right but both sides of the room, thats 68mm and I dare say it would outperform the other method being directly mounted onto the wall without the need for battens, rockwool and resilient channel which would significantly increase available space..

[James Perrett]

Re-read Idris' first reply. Directly mounted sheets of anything aren't going to help much. As I understand it, you will at least need to mount them on resilient channel.

James.

[Oliver21]

What am I missing here? Surely 4mm of lead directly mounted to anything would be the end of it. The wall would be so massive (@ 45kg per m2) the resilient channel would would become, if not irrelevant then very insignificant.

[James Perrett]

A single layer of your existing concrete blocks are going to be at least double that mass per unit area and, from what you say, two layers aren't sufficient so the equivalent of an extra couple of inches of block isn't gong to change things much. Adding a compliant layer is the important thing here - simply attaching the lead lined sheet directly to the wall isn't going to do anything to stop vibrations being transmitted through the wall.

To be honest, I'd say that your walls are the least of your problem - the doors and roof are probably much weaker than the walls.

James.