New Studio Premises - Ceiling construction etc

Hi there I am due to be taking on the lease of a business premises within the next couple of months where I intend on relocating my recording studio and I would really appreciate some advice on some aspects of construction, in particular the ceiling construction/design for one of the rooms and I'm hoping that folk here would be kind enough to offer me some feedback and suggestions. I am a first time poster here and although I believe that I have followed all the guidelines and rules regarding posting in this forum, should I have omitted any necessary info or overlooked anything then please let me know. Ok, here is an overview: - I intend on using the proposed studio premises for recording bands and catering for vocals, drum kit, guitars, keyboard etc. - The premises is located on the ground floor, single story, and is of flat roof design. - Semi detached with just one party wall (stud wall) joining on to another unit which is used purely for storage by the Freeholder/landlord. - All other walls (both internal and external) are of solid brick construction (more details and photos provided below) - Solid concrete flooring throughout. The premises consists of 3 rooms: Room 1 21' x 10' with 9.5' high ceilings I intend on using this room as the control room and for general recording duties such as guitar etc. Room 2 9' 11" x 7' with 9.5' high ceilings I intend on using this as a small kitchen/reception area which may also be used as an isolation room for certain recording sessions if necessary. Room 3 14' x 12' I intend on using this space as an isolation room for recording drums etc and it will also serve as a small rehearsal space for bands to practice. This is the room that i really want to focus on with regards to reducing sound transmission as much as possible and its weakness is the ceiling. It currently has a lower ceiling height of 8' (the other 2 rooms measure 9.5') and the ceiling consists of old flimsy plastic tiles. I managed to work one of these tiles loose to see what we are dealing with behind and gain some measurements etc. - There is 30inch between the actual roof and this ceiling. - As you would expect, the roof is supported by wooden joists which appear to be held in place by iron girders. - This room currently has a ceiling height of 8' whereas the adjoining rooms have a ceiling height of 9.5' - I am therefor assuming that there is approx 18" available with regards to the new ceiliing that is being put in, ideally increasing the ceiling height in this room from 8' feet to at least 8.5' (the higher the better but without compromising the sound isolation). My current thoughts are to: - Remove current ceiling in this room - Fit a layer of plasterboard to main joists to create a main ceiling at the same height as the other rooms (9.5') which would assist us in reducing sound transmission. - Install a 2nd ceiling 1' below this by suspending new joist from joist hangers that are to be attached to the walls. - Appropriate insulation placed between the joists. - This should result in a new ceiling height of approx 8.5' This room has one door leading to Room 1/Control room (see images attached) and I intend on installing a double glazed sliding door that will seperate Room 3 from Room 2/kitchen area (again, please see images attached) as this is currently open plan. Ok, so here are my questions: 1. Does my proposed approached to installing a new independent ceiling sound appropriate to my needs? 2. If so, how much distance would you suggest I leave between the first/main ceiling and the 2nd? Ideally I wish to have my ceiling as high as possible but with best possible reduction in sound transmission. 3. Which type of insulation would be best to install between the joists of the independent ceiling in order to reduce sound transmission as much as possible? Dense Rockwool (RW6/Prorox SL980)? 4. What would you recommend regarding the plasterboard - 2 layers of 19mm? I have included some images below for your consideration. These images consist of: - A photo of the exterior of the premises - A photo showing details of the wall exterior wall construction. The previous tenant had installed a vent which has proved useful in enabling me to access the wall construction but will be closed off. - A few screenshots from Sketchup showing the room dimensions and proposed layout Any input and advice would be greatly appreciated. Many thanks in advance!

Hi there and welcome :D

mr-b76 wrote:

I am a first time poster here and although I believe that I have followed all the guidelines and rules regarding posting in this forum, should I have omitted any necessary info or overlooked anything then please let me know.

Budget is quite a big omission :shock: and also we need to know what kind of db level you require outside the studio to be able to give advice regarding construction. From the exterior pic it would seem you're in a built up area, which implies a high level of isolation to avoid frequent knocks on the door from authorities. It looks like you have a single leaf wall construction going by your sketchup pics, which will probably not give you the isolation you need for a drum kit. The exterior windows will also be an issue as they aren't giving you much isolation to start with.

mr-b76 wrote:

1. Does my proposed approached to installing a new independent ceiling sound appropriate to my needs? 2. If so, how much distance would you suggest I leave between the first/main ceiling and the 2nd? Ideally I wish to have my ceiling as high as possible but with best possible reduction in sound transmission. 3. Which type of insulation would be best to install between the joists of the independent ceiling in order to reduce sound transmission as much as possible? Dense Rockwool (RW6/Prorox SL980)? 4. What would you recommend regarding the plasterboard - 2 layers of 19mm?

1-an independant ceiling (2 leaf construction) needs to resting on independant (2 leaf) walls to be useful. 2- the biggest gap possible s best as it lowers the resonant frequency of the cavity, thus giving you better bottem end isolation. Make it as wide as is practical. 3-rockwool with a density of around 50 kg/m is what you need. 4- 2 layers of plasterboard is great, although i'm not sure it's made in 19mm. I think you'll find plasterboard is 16mm and ply/mdf is 19mm. That's the story in Oz, but may be different where you are. hope there's some useful info there, and good move coming here for advice before you start construction :D steve

Hi Steve, and many thanks for your reply. Regarding budget, things are kinda tight and I only have around £2000 allocated for the kitting out of this room in question but being as sound isolation is a priority, I can put some other aspects of the studio on the backseat for now and put more money into the sound isolation if necessary. Regarding the wall construction, the exterior wall is actually a cavity/2 leaf wall comprising of 8.5" brick (outer leaf), 3" of insulation (appears to be some type of loose polystyrene?), and 4" of breeze block (inner leaf). So sorry my sketch up design didn't reflect this. I started the sketchup design upon taking the room dimensions on my first visit to the premises and before I discovered the construction of the wall and was supposed to amend this once I found out, cant believe I forgot to do so, apologies for any confusion caused. I will try to amend my sketchup designs but have only just started to learn how to use the program so sometimes struggle to find how to make even simple changes. :? Details of the cavity wall can be seen in the photo I provided towards the bottom of my original post. So if the joist hangers are attached to the inner leaf/breeze blocks of the exterior wall and then attached to the interior wall on the other side, will this suffice in creating the necessary isolation when installing the ceiling? Regarding the 19mm plasterboard/gypsum/gyprock, I have found this in the UK, does this seem suitable? http://www.jewson.co.uk/building-materi ... 00-x-19mm/

mr-b76 wrote:

Regarding budget, things are kinda tight and I only have around £2000 allocated for the kitting out of this room in question but being as sound isolation is a priority, I can put some other aspects of the studio on the backseat for now and put more money into the sound isolation if necessary.

that'll be pretty tight, but hopefully you're able to do a lot of the construction work yourself. If you have to hire contractors that won't go very far :(

mr-b76 wrote:

Regarding the wall construction, the exterior wall is actually a cavity/2 leaf wall comprising of 8.5" brick (outer leaf), 3" of insulation (appears to be some type of loose polystyrene?), and 4" of breeze block (inner leaf).

wow, that's a serious wall construction which is perfect for a studio with a few notes....are the two walls tied together with metal ties? if they are then sound will transmit through the ties. There's probably nothing you can do about this given the building is already there. It's worth rendering the inside of the breeze block if possible to seal up any airgaps there might be. This makes a considerable difference to your isolation.the insulation looks like it's the 'blow in' kind which won't have the right density for cavity damping unfortunately.

mr-b76 wrote:

So if the joist hangers are attached to the inner leaf/breeze blocks of the exterior wall and then attached to the interior wall on the other side, will this suffice in creating the necessary isolation when installing the ceiling?

you're half right :D it'll make your ceiling independant of your exterior wall, but if you only have a single leaf internal wall then it'll couple your rooms together if you join your other internal ceiling to this wall. You'll need to build seperate internal (2 leaf) walls for your other ceilings.

mr-b76 wrote:

Regarding the 19mm plasterboard/gypsum/gyprock, I have found this in the UK, does this seem suitable?

looks like a great product and one i've not seen before. As they're narrow sheets you'll have a lot of joining to do. It doesn't say whether they have a tapered edge which may make sealing and joing the sheets a bit more fiddly. steve

"- Fit a layer of plasterboard to main joists to create a main ceiling at the same height as the other rooms (9.5') which would assist us in reducing sound transmission. - Install a 2nd ceiling 1' below this by suspending new joist from joist hangers that are to be attached to the walls." With an existing flat roof, you would be more inclined to use clips and hat track to develop a decoupled system. What you are suggesting is a typical three leaf that will reduce the transmission loss in the low area, and who needs that.

yep, Brien's got your back and is 100% right. I missed that you were proposing a 3 leaf construction :oops: the great thing about this forum is that you have several pairs of eyes looking over your shoulder :D

Thanks Steve "wow, that's a serious wall construction which is perfect for a studio with a few notes....are the two walls tied together with metal ties? if they are then sound will transmit through the ties. There's probably nothing you can do about this given the building is already there. It's worth rendering the inside of the breeze block if possible to seal up any airgaps there might be." Not too sure about the wall ties but as you point out, if they are present then I guess there is not much I can do about this. Regarding the rendering of the inside of the breeze blocks, the whole room is completely tiled so airgaps in the blocks will not be an issue. I intend on applying plasterboard to the walls and then treat the room broadband absorbers and ideally some bass traps if the space allows. Hi Brien, and thanks for your post. Could you please elaborate on what you mean by... "What you are suggesting is a typical three leaf that will reduce the transmission loss in the low area, and who needs that." If I am trying to sound proof the room as much as possible so that the noise from within is not disturbing the outside world then surely reducing the transmission loss (especially in the low frequencies) is a good thing?

mr-b76 wrote:

Thanks Steve If I am trying to sound proof the room as much as possible so that the noise from within is not disturbing the outside world then surely reducing the transmission loss (especially in the low frequencies) is a good thing?

Well, it isn't a numerical subtraction. The reduction in transmission loss means you will reduce the ability of the system to contain the low frequency. This is a known issue, the three leaf, that continues to be misunderstood via the Internet myths that continue to support it. Hope that helps.

Hi there "mr-b76", and welcome to the forum! :)

I intend on applying plasterboard to the walls

Why? If the walls are already tiled all around, then why do you want to put drywall on top of that, then cover the drywall over with treatment?

then treat the room broadband absorbers and ideally some bass traps if the space allows.

Bass traps are not just a "maybe, if I can fit them in": rather, they are an absolute necessity, not even the slightest question about it. It's a small room so it WILL need bass trapping, and lots of it. All three rooms are small, and all three will need bass trapping, but the control room is the most critical so it will need the most bass trapping. The live room will also need some, but not to the same extent as the CR, basically because it is a Live Room, it can have a bit of character of it's own... as long as the "character" is harmonious, pleasant, and comfortable for musicians. With no bass trapping it all, it won't... And since it is a smaller room than the CR, it will need relatively more bass trapping, to get the modes under control. Also, since it is not a control room (where the position of the speakers is fixed), it is probable that all possible modes could be triggered, so the bass trapping needs to be designed with that in mind.

If I am trying to sound proof the room as much as possible so that the noise from within is not disturbing the outside world then surely reducing the transmission loss (especially in the low frequencies) is a good thing?

No, if you want MORE isolation you want to INCREASE the transmission loss, not reduce it! If you reduces the transmission loss, then you would have LESS isolation. And as Brien pointed out, a 3-leaf system will have REDUCED transmission loss in the low frequencies, which is exactly where things like drums, bass, keyboards, and electric guitars put out lots of energy. That's where you need the most transmission loss you can get. And 3-leaf will give you less of it than 2-leaf, in low frequencies. Also, "soundproofing" isn't a term that is used much in acoustics, since it means different things to different people, and can't be achieved anyway, in the real world! As implied by Brien's signature: it is impossible to stop sound. Any sufficiently loud sound will penetrate any conceivable barrier that Man could possibly build. "Isolation" is the term you hear most often, which sort of means what most people think of when they say "I want to soundproof this room". You mentioned your "Room #3" a lot, saying that you need to isolate it for drums, but you didn't say how much isolation you need, so its impossible to say if your plan will achieve what you are hoping, or not. You should fist put a number to that, in terms of: "I need xx decibels of isolation to/from the outside world, and yy decibels of isolation to the other rooms". Based on real numbers, it is then much simpler to come up with construction techniques, materials, and dimensions that will get you that amount of isolation. Without having a number, it's all just guesswork. But the one issue that is for certain, is that your currently planned 3-leaf roof won't be as good at isolating low frequencies as the equivalent 2-leaf. That doesn't mean that you cannot build a 3-leaf: it just means that if you do decide to build a 3-leaf, you will have to compensate for the reduced isolation (and higher MSM frequency) by increasing the total mass and also increasing the size of the two air gaps. That implies extra cost for the heavier materials, and lost space (headroom) due to the need for larger air gaps, so if this can be avoided, then it's a good idea to do so. That said, it is not always possible to make a 2-leaf work, and sometimes you do have to.

2. If so, how much distance would you suggest I leave between the first/main ceiling and the 2nd?

We'd need to know the amount of isolation (dB) that you are shooting for, in order to figure that out.

3. Which type of insulation would be best to install between the joists of the independent ceiling in order to reduce sound transmission as much as possible? Dense Rockwool (RW6/Prorox SL980)?

The insulation does NOT stop the sound from getting through: that's a common misconception. What the insulation actually does is to damp the MSM resonance in the wall cavity. It serves the same purpose as the shock absorber on your car: it damps oscillations. In fact, your entire wall works exactly like the suspension on your car. There too you have an MSM system (Mass-Spring-Mass), and just like your wall, it is tuned to a specific frequency. The wheel is one "mass", and the spring separates it resiliently form the other mass, which is the car. Without the shock absorber in place, it is really good at stopping road vibrations from getting through from the wheel to the car. In other words, it is a vibration isolator, just like your wall. But if you happen to drive over a road that causes it to vibrate at its resonant frequency, it becomes a really lousy isolator, and not only transmits that vibration to the car, it also amplifies it. That's where the shock absorber comes in. In fact "shock absorber" is a really bad name for it, since it does not absorb shocks at all! What it does do, is to damp the vibrations in the suspension system. And that's what the insulation in your wall does: it damps resonance inside the cavity. Without that, your wall would be a really lousy isolator around the MSM resonant frequency of the wall. But it does not, of itself, stop sound getting through, any more than the shock absorbers in your car stop the bumps from getting through. So, the insulation has to have the correct characteristics to act as a damper in an acoustic MSM resonant system, and it turns out that the optimum density for that is 50 kg/m3 in the case of mineral wool, and 30 kg/m3 in the case of fiberglass. Either of those will work just fine, provided that you get the correct density. If you get stuff that is too dense, then it won't damp the low frequency resonances in the wall cavity (it will only damp the higher harmonics). And if you get stuff that is too light, then it won't damp the higher frequency resonances well (it will only damp the fundamentals, assuming that you don't get it way too light, in which case it won't even damp those!). It's a common myth that "more dense is better". In reality "optimal density is better, and either too dense or not dense enough is bad".

4. What would you recommend regarding the plasterboard - 2 layers of 19mm?

Probably, but once again that can only be calculated once you have your number: how many decibels of isolation you need. That said, there are also structural issues: You'll need to get a structural engineer to take a look at what you have there, and tell you how much more stress (weight) you can put on it safely. Hopefully there is still enough dead-load margin in there that will allow you to add the mass you need to get the isolation you need.

The previous tenant had installed a vent which has proved useful in enabling me to access the wall construction but will be closed off.

Not just "closed off" but totally "bricked up" to get it the same as the rest of the wall. That's a serious, SERIOUS weak point in your isolation system. It needs to be returned to how it was before, with the same surface density as the rest of the wall.

- A photo of the exterior of the premises

I see lots of glass, and I see doors that open the wrong way, and seem to be typical thin hollow-core or foam-core doors. Those are all very serious weal points in your isolation shell. The surface density of that glass is only a small fraction of the surface density of the brick, so all that will need replacing with thick laminated glass, that gets the surface density up to something useful. And the doors will need replacing with something far more substantial, much more massive, and that open outwards, not inwards.

things are kinda tight and I only have around £2000 allocated for the kitting out of this room in question but being as sound isolation is a priority, I can put some other aspects of the studio on the backseat for now and put more money into the sound isolation if necessary.

Depending on how much isolation you need, your budget is very likely inadequate. Just the HVAC system for one of the rooms will take a serious bight out of that! And you can't do without HVAC...

So sorry my sketch up design didn't reflect this.

It would be good if you could update it and correct it, so that it accurately reflects how the place is really built, now that you have figured that out.

I will try to amend my sketchup designs but have only just started to learn how to use the program so sometimes struggle to find how to make even simple changes.

It looks pretty good so far! As long as you are taking care to create "components" and pare putting related things on "layers", then it is easy to update. - Stuart -

Hi stuart, and many thanks for your detailed and informative post. I will take onboard your feedback, revist the plans etc and report back at a later date. One quick question. You mention that it is important for the exterior doors to open outward rather in inwards, why is this exactly?

You mention that it is important for the exterior doors to open outward rather in inwards, why is this exactly?

Because the matching interior door that goes just next to that one, on the inner leaf, will open inwards, into the room. They have to open in opposite directions. There's no other way of doing it.... :) - Stuart -