John Sayers' Recording Studio Design Forum Archive

Hi,

My name is Chris, I’m based in the UK and currently in the process of converting a garage to a music production room. The aim to isolate the space as best as possible, while creating a great space for spending lots of time in.

I produce music for a living, and hope that it will be a main work space for writing/creation for the next 5 - 10 years.

My current studio is set up in a rental house, and the last three years have been hampered by neighbours who are in all day every day and complain about everything. From blenders running to doors closing, to the sound of our son crying, they have either commented on it or made formal complaints to our landlords.

Very stressful situation to manage for a music producer/DJ, lover of music and life.

Fortunately my partner and I have recently purchased our first house, which we have been renovating since December.

Detached from the house is the garage on which the first stages of construction have started.

I naively walked into the space when viewing the house for the first time and said to myself “I can make this a studio”. As the months have rolled by and the research has deepened, I have tumbled down the the rabbit hole and realised what an undertaking sound isolation really is, especially if the space is to be comfortable and inspiring to be in.

I’m currently researching and planning/designing, and on the cusp of beginning the construction of the room within the room of the existing single skin garage. This will begin in the next three weeks.

The plan is to build the stud work leaving an air gap from the wall, insulate the studs, then use resilient channels to mount two layers of 15mm plasterboard sandwiching green glue. All gaps and cracks are to be caulked with acoustic sealant.

I had taken inspiration from several studio builds, including examples from this forum, and like others before me have started to look at ventilation and to quote a contributor to this forum (Waka), I find myself doing the following exactly…..

“stare blankly at your sketchup design for hours into the night slowly hating them (silencer boxes) a little more as each minute passes by, until finally... You will have squeezed them into a ceiling void or speaker baffle, or dropped soffit, or all three and with a sigh of relief realise... Your studio can now be... Suitable for humans.”

Things might not be that bad (I’m currently on a high after a 12 hour research binge), but the HVAC system design did not get the love it deserved in the maelstrom of project managing both house renovation and studio self build. A visit from an air conditioning installer soon got things kick started in that department and I am now here hoping to iron out the design.

I’ll start getting into more useful detail.

EXPECTATIONS

- I work between 75 - 85db
- I want to able to push this from time to time while working on new material
- I would like to achieve the best reduction possible using the design outlined below (I understand it will not be soundproof, but as yet, do not know what the STC performance of the weakest part of the design will achieve, likely the doors). Can I achieve 40 or 50db?
- Neighbours at the new house are amazing, old musician on one side who complains about quiet it is, and offers milk and tea to our builders. The other neighbour loves music, big fan of Ninja Tune, Mo Wax and similar labels
- The garage is attached to a neighbours garage
- The corner of the garage to the corner of the neighbours house is 4 meters in a diagonal line, but is completely detached from any dwelling
- I’ve never built an isolated room before, so my terms my be out here and there, and I’m currently feeling a touch overwhelmed, but positive overall and looking forward to get started in earnest as soon as possible.


- THE GARAGE



- 4750mm L x 2430 W
- Original roof is pitched from 2200mm at top plate of wall up to 3370 at ridge
- Exterior rendered
- Floor is currently a rough un-even concrete slab
- Construction is single skin concrete block (100mm thick)
- 25mm Celotex has been fixed to single skin blockwork
- Garage door has been removed and blocked up using timber frame and OSB
- The roof is slate with felt. To improve the performance of the roof we have installed a new leaf
- Added new wall plates to hang new rafters for the flat part of the first roof leaf
- Added an additional purlin and run buttons horizontally across the rafters to allow us to mount….
- Two layers of 15mm Gyproc Soundbloc sandwiching Green Glue
- Ventilation for the roof structure between rafters has also been achieved by vents in the facia.
- All gaps have now been acoustically sealed in roof.
- With this work the ceiling height has come down to 2900mm
- The current room is not rectangular as the boarding follows the pitch of the roof and is flat for a distance of 2170mm
- An opening has been made in the side of the structure, to which a fire door has been installed (modular locks have been fitted that do not leave an open hole in the door, Scandinavian and euro cylinders to be precise. I will also add mass to this door using MDF and add a layer of green glue
- Gaps around door frame are to be filled with Everbuild Gun Grade Thermofoam Insulation Foam (64db rating, I don’t know at what frequency this is though)

Room shape should be clearer with the draft Sketchup model we are using along with photos so far

This is the work to date on the main garage/studio structure.

Going forward the plan is…

- SUB STRUCTURE

- Install a timber stud structure for floor, walls, and ceiling leaving air gap of approx 10 - 20mm
- Fill stud cavities with RW3 or other suitable insulation
- Use resilient channels to mount two layers of 15mm Gyproc soundbloc to ceiling and walls (sandwiching Green Glue)
- Fill gaps with Acoustic sealant
- Floor make up will be…
- Insulation > Stud (Insulated RW3 or other) > Chipboard > Final Floor Finish TBC
- I will use self adhesive acoustic isolation strip at all contact points on the stud
- Secondary Fire Door to be installed into Sub structure again with extra mass from MDF with green glue

- ELECTRICS
- Power and data to be run to studio from house in armoured conduit
- Will be run into the studio at low level and up through floor makeup
- Consumer unit to be installed by electrician
- Trunking will be used throughout for power, data, and lighting


HVAC
- Install externally mounted centrifugal extractor fan run though a single silencer box to be concealed in cavity
- Air outlet to be run through silencer to exterior (no fan)
- AC/Heat pump currently specced
- 2.5kw Daikin FTXP25L


BUDGET
- The remaining budget is £ 6000 - £8000
- This will need to take care of sub structure, electrics, and HVAC. Plus some furniture too if possible (work desks for e.g.)
- Price quoted for AC is £1.3k
- Power and data to studio plus the studio consumer unit is currently allowed for from electricians spec budget for the house, trunking +lighting in studio will be extra.

I will be carrying out the build with my friend who is a carpenter and cabinet maker. He is also a producer/dj who has built a studio space before.

The main contractor for the house is also going to be on site, he has been incredible so far, and is around to give us pointers along the way.

QUESTIONS

- How am I doing so far?

- Resilient channels
- Will these be necessary if the stud frame is isolated from the existing block work?

- Expanding foam choice - https://bit.ly/2Ws1iFO
- Is this a good option?


- HVAC
- What brand of extractor is recommended in the UK?
- with approx 26 cubic meters, would a fan with capacity for 280m3/hr be ok?
- Will this type be a good option? https://bit.ly/2uEaICh
- I will get an exact volume before purchase of any fan

I’m currently looking like I will need to put both the inlet and extractor vent at the same end of the room.
- They will still be venting from opposing walls though.
- Both silencers will be lost in the same cavity to save space



Blocking of garage door
- To prevent creating a third leaf, I would like to add mass to the inside of the OSB by attaching layers of MDF layered with green glue. They would need to be cut to size to fit inside the cavities left by the stud work. The remaining space in the cavity can be filled with RW3 and held in place with netting. Is this a bad idea. Th other option would be to insulate the gaps in the stud, and board over, thus creating a third leaf, which I understand I should avoid.

If you’ve read all of the above then I’m already grateful. Thank you for any pointers and guidance will be much much appreciated.

Chris

images

Welcome Chris!

I apologize if these are short and blunt answers. I don't have much time right now.

This will begin in the next three weeks.

Don't book any contractors until your design is 100% done. It seems you've already jumped the gun. Unless your able to spend 16 hrs a day for the next 3 weeks on your studies and design, I doubt you'll be ready to start building in 3 weeks.

- I work between 75 - 85db

Since you've measured how loud you work inside, take your handheld SPL meter and measure how loud it is outside on a normal day. Also, how do the noise regulations work for adjoining properties like yours?

The difference between your 85dbC and how loud it normally is outside or what the noise regulations are (choose whichever is loudest), THAT's how much isolation you need. Right now you've made a plan for isolation without knowing how much isolation you need. You could be spending way too much time/money on isolation or not enough. Imagine you build this room and one of your cool neighbors moves away and you get a super grumpy person replacing them. You have the cops handing you tickets and you legally have to shut it down. Build it right the first time.

- I would like to achieve the best reduction possible using the design outlined below (I understand it will not be soundproof, but as yet, do not know what the STC performance of the weakest part of the design will achieve, likely the doors). Can I achieve 40 or 50db?

The fact that you've mentioned STC in your post unfortunately points out that you haven't done enough research to be building your place yet. That's why I mentioned above that you may have jumped the gun doing ANY construction so far. Have you taken readings with you SPL meter set to C weighting and slow to determine the amount of isolation you require? Is it 40 or 50 you need? Or how much? STC basically has nothing to do with music studios and their isolation.

- I’ve never built an isolated room before, so my terms my be out here and there, and I’m currently feeling a touch overwhelmed, but positive overall and looking forward to get started in earnest as soon as possible.

We're here to help.

- Original roof is pitched from 2200mm at top plate of wall up to 3370 at ridge

Unfortunately you're going to have some compression happening at the back of your room due to the ceiling shape.

- Floor is currently a rough un-even concrete slab

Level it if you want, but leave it a hard surface. If temperature is a concern, get some thin appropriate underlay and put something like laminate flooring on it. Leave it otherwise. Do NOT try to float it like you have drawn.

- 25mm Celotex has been fixed to single skin blockwork

Not good. From what I have read, that product does nothing for acoustics. Unless someone here is more familiar with the product who can provide more info, I'd say rip that off and use insulation with the correct gas flow resistivity to actually help with your isolation. Right now, acoustically speaking, I believe you have done nothing other than hinder your isolation by applying this product.

- Garage door has been removed and blocked up using timber frame and OSB

How thick of OSB? Have you used the mass law equation to see how much transmission loss you are achieving with the surface density of the OSB?

- The roof is slate with felt. To improve the performance of the roof we have installed a new leaf
- Added new wall plates to hang new rafters for the flat part of the first roof leaf
- Added an additional purlin and run buttons horizontally across the rafters to allow us to mount….
- Two layers of 15mm Gyproc Soundbloc sandwiching Green Glue

"first roof leaf"... so your original roof that has felt on it ... this is your first leaf. You have now added another one with two layers of gyproc. What was the first roof leaf made out of under the felt?

- Ventilation for the roof structure between rafters has also been achieved by vents in the facia.
- All gaps have now been acoustically sealed in roof.

Two contradicting statements back to back.

- An opening has been made in the side of the structure, to which a fire door has been installed (modular locks have been fitted that do not leave an open hole in the door, Scandinavian and euro cylinders to be precise. I will also add mass to this door using MDF and add a layer of green glue

I hope you plan to add several layers of seals to this door, yeah?

- Gaps around door frame are to be filled with Everbuild Gun Grade Thermofoam Insulation Foam (64db rating, I don’t know at what frequency this is though)

Just like the insulation you already added, this "thermofoam" is exactly that - Foam. This has no place in isolation of a studio. Use waterproof, shrinkproof silicone. You need the density that foam does not provide in this situation. Instead of filling the ENTIRE cavity with silicone, you could lightly fill the middle portion with proper insulation and then encapsulate the insulation with silicone.

- Install a timber stud structure for floor, walls, and ceiling leaving air gap of approx 10 - 20mm

Okay so you want to build a room in a room. You already just wasted a ton of height by adding your second leaf ceiling. But, if your engineer says you need an attic that can breath, what you've done is fine. However, you should have done it using modules inside out style and maintained your much needed ceiling height.

Also, ditch the floor plan you have. Just keep the concrete. Again, put some suitable hard flooring down if you need, but do not try to float your floor. You do not have the space or money for that.

- Use resilient channels to mount two layers of 15mm Gyproc soundbloc to ceiling and walls (sandwiching Green Glue)

No. If you are building a room in a room, you do not use clips or hat or channel of any kind.

- Floor make up will be…
- Insulation > Stud (Insulated RW3 or other) > Chipboard > Final Floor Finish TBC
- I will use self adhesive acoustic isolation strip at all contact points on the stud

Scrap that.

- Trunking will be used throughout for power, data, and lighting

Explain "trunking" in more detail please.

- Install externally mounted centrifugal extractor fan run though a single silencer box to be concealed in cavity
- Air outlet to be run through silencer to exterior (no fan)

If you've determined you need the isolation provided by a room in a room, you will need a silencer box on both your inner and outer leaves, both for supply and return. That's a total of 4 silencer boxes.

What size of fan? I see you haven't designed your silencer boxes yet, but make sure it will move x amount of air under x amount of static pressure imposed by your silencer boxes.

- AC/Heat pump currently specced
- 2.5kw Daikin FTXP25L

Please show us the calculations so we can ensure you're getting the right unit.

He is also a producer/dj who has built a studio space before.

Can you show us pictures of and REW data for his studio?

- How am I doing so far?

You're on the right track but clearly have lots of learning and design to do. Just keep plugging away at it!

- Resilient channels
- Will these be necessary if the stud frame is isolated from the existing block work?

No.

- Expanding foam choice - https://bit.ly/2Ws1iFO
- Is this a good option?

No. Never use this. For anything.

- HVAC
- What brand of extractor is recommended in the UK?
- with approx 26 cubic meters, would a fan with capacity for 280m3/hr be ok?
- Will this type be a good option? https://bit.ly/2uEaICh
- I will get an exact volume before purchase of any fan

Your last line answers all of your questions.

I’m currently looking like I will need to put both the inlet and extractor vent at the same end of the room.
- They will still be venting from opposing walls though.
- Both silencers will be lost in the same cavity to save space

Your supply and return have to be at the opposite ends of your room. They can penetrate your leaves near one another, but in order to actually work, they need to be as far apart as possible.

Blocking of garage door
- To prevent creating a third leaf, I would like to add mass to the inside of the OSB by attaching layers of MDF layered with green glue. They would need to be cut to size to fit inside the cavities left by the stud work. The remaining space in the cavity can be filled with RW3 and held in place with netting. Is this a bad idea. Th other option would be to insulate the gaps in the stud, and board over, thus creating a third leaf, which I understand I should avoid.

Yes, add mass to the inside of the OSB. Do not create a 3rd leaf.

If you’ve read all of the above then I’m already grateful. Thank you for any pointers and guidance will be much much appreciated.

Continue on your 3D modeling. Get every last detail sorted out before you lift another screw. Please continue on this thread that you've started -- post pictures, questions, calculations, etc.

I look forward to seeing it!

Greg

Gregwor wrote:Welcome Chris!

I apologize if these are short and blunt answers. I don't have much time right now.

Thanks for the welcome Greg, and for taking the time to review my project, especially if time is tight. It means a lot!

I don't find the answers short at all, and given where I am with the project they cut straight to the chase which is exactly what I need right now, given that time is tight!

Gregwor wrote:Don't book any contractors until your design is 100% done. It seems you've already jumped the gun. Unless your able to spend 16 hrs a day for the next 3 weeks on your studies and design, I doubt you'll be ready to start building in 3 weeks.

There is flexibility here, but it will be a matter of weeks till I get started. I am fortunate enough to be in a position to dedicate all of my time to this project till it is complete, so I will be spending 8 - 10 hours a day making sure I get the best build possible.

You are right I have jumped the gun, but worse than that, I've made assumptions about a suitable spec based on my existing limited knowledge, and then acted on those assumptions.

I totally underestimated how much work buying a house, completely renovating it, and adding an extension was going to be.

While in the maelstrom of this process the studio design has taken a back seat, and I've had to make decisions often without adequate time to prepare, but I'm ready to delve deep into the project now, as the house is now fully specced till it's completion.

Gregwor wrote:Since you've measured how loud you work inside, take your handheld SPL meter and measure how loud it is outside on a normal day. Also, how do the noise regulations work for adjoining properties like yours?

The difference between your 85dbC and how loud it normally is outside or what the noise regulations are (choose whichever is loudest), THAT's how much isolation you need. Right now you've made a plan for isolation without knowing how much isolation you need. You could be spending way too much time/money on isolation or not enough. Imagine you build this room and one of your cool neighbors moves away and you get a super grumpy person replacing them. You have the cops handing you tickets and you legally have to shut it down. Build it right the first time.

I took a measurement of my current set up some time ago to provide those readings. I used a cheap sound level meter. Having reviewed the posting guide, I've sourced a better meter from ebay, this one to be precise - https://bit.ly/2UgA7jG

That will be with me in a few days, I will take the advised reading then and post results.

"Permitted noise levels

The permitted noise level using A-weighted decibels (the unit environmental noise is usually measured in) is:

34 dBA (decibels adjusted) if the underlying level of noise is no more than 24 dBA
10 dBA above the underlying level of noise if this is more than 24 dBA"

Above is quoted from here - https://bit.ly/2p5h4K5

From another UK source I have found the following.....

"A noise level of 35 to 40dB outside a dwelling is acceptable and a maximum of 45dB should be adhered to in order to prevent disturbance to residents"

Given those numbers, could a figure of 40db - 50db be a realistic isolation target to aim for?

Gregwor wrote:The fact that you've mentioned STC in your post unfortunately points out that you haven't done enough research to be building your place yet. That's why I mentioned above that you may have jumped the gun doing ANY construction so far. Have you taken readings with you SPL meter set to C weighting and slow to determine the amount of isolation you require? Is it 40 or 50 you need? Or how much? STC basically has nothing to do with music studios and their isolation.

Thanks for pointing this out, I'll go and learn about this topic in depth and come back with proper reading when the new meter arrives.

Gregwor wrote:Unfortunately you're going to have some compression happening at the back of your room due to the ceiling shape.

That is a shame.

It's not to be used as critical listening space, it's primarily for electronic music production, Synths, Drum Machines, Sampling and DJing.

But I will also be mixing material here too, so will be coming back for more advise on treatment as the design progresses

Gregwor wrote:Level it if you want, but leave it a hard surface. If temperature is a concern, get some thin appropriate underlay and put something like laminate flooring on it. Leave it otherwise. Do NOT try to float it like you have drawn.

OK will do. I'll research options here.

I was building the floor frame to level and insulate for warmth. It also allowed me to easily get a damp proof membrane in too.

Why shouldn't I float the floor?

What floor make up would you advise?

Do I really need a damp proof membrane?

Gregwor wrote:Not good. From what I have read, that product does nothing for acoustics. Unless someone here is more familiar with the product who can provide more info, I'd say rip that off and use insulation with the correct gas flow resistivity to actually help with your isolation. Right now, acoustically speaking, I believe you have done nothing other than hinder your isolation by applying this product.

Celotex has been applied for thermal reasons only, and to act as a vapour barrier. This was specced by two builders who noted that with the high level of insulation on the inner room, the dew point would move.

Note that the Celotex has currently only been applied to the most upper section of the wall where the layers of plaster board have been added to the roof structure.

Any Celotex below the current Plaster board leaf can be removed and replaced with an alternative if necessary.

Is there an alternative form of insulation that can be applied directly to the single skin block work, that will act as a vapour barrier and provide isolation gains?

Gregwor wrote:How thick of OSB? Have you used the mass law equation to see how much transmission loss you are achieving with the surface density of the OSB?

The OSB is 18mm thick, and I haven't done a calculation on this.

I will be adding mass to this from the inside with MDF layers sandwiching green glue

Gregwor wrote:"first roof leaf"... so your original roof that has felt on it ... this is your first leaf. You have now added another one with two layers of gyproc. What was the first roof leaf made out of under the felt?

The original roof structure is comprised of man made tiles on top of felt. Not air tight.

Just to clarify..

When I said

- Ventilation for the roof structure between rafters has also been achieved by vents in the facia.
- All gaps have now been acoustically sealed in roof.

The ventilation has been installed between the rafters of the original slate roof, it's required for me to keep the air flow up there to prevent rot.

The Two layers of Plaster board were fit with a 5mm gap to the edges and then sealed at at the perimeter and every, join thus making the space below the added leaf airtight to the ventilated roof structure above.

I did not count the slate tiles as a leaf in insulation terms as it is not air tight and ventilated. It is a watertight breathable roof covering the newly installed two leaf plasterboard ceiling make up.

I have to say, this was one of my assumptions I hope I haven't goofed up to bad here.

Gregwor wrote:I hope you plan to add several layers of seals to this door, yeah?

Yes two seals one for the off the shelf fire door, and a seal for the MDF mass that we plan to add.

Gregwor wrote:Just like the insulation you already added, this "thermofoam" is exactly that - Foam. This has no place in isolation of a studio. Use waterproof, shrinkproof silicone. You need the density that foam does not provide in this situation. Instead of filling the ENTIRE cavity with silicone, you could lightly fill the middle portion with proper insulation and then encapsulate the insulation with silicone.

Thanks for stepping in here, I'll hold of sealing the gap between one side of the door frame and the block work.

Here is the gap
How can I fill this and ensure I get the best isolation result?

I will also be installing a second door to the internal room btw. With the same spec.

Gregwor wrote:Okay so you want to build a room in a room. You already just wasted a ton of height by adding your second leaf ceiling. But, if your engineer says you need an attic that can breath, what you've done is fine. However, you should have done it using modules inside out style and maintained your much needed ceiling height.

Also, ditch the floor plan you have. Just keep the concrete. Again, put some suitable hard flooring down if you need, but do not try to float your floor. You do not have the space or money for that.

Indeed the attic needs to breath. We also needed to add lateral strength and remove and replace a roof tie. The installed wall plates carry out both of these tasks and allowed us to run the rafters horizontally. We got the maximum height possible from the design. Given that it has been recommended that we don't float the floor, we can still end up with 2700mm ceiling height at the highest point.

Is that reasonable?

Gregwor wrote:No. If you are building a room in a room, you do not use clips or hat or channel of any kind.

Thanks for clarifying this.

Gregwor wrote:Explain "trunking" in more detail please.

Electrics will be run around perimeter of room in trunking fitted to wall, all power and data outlets will be added as necessary to trunking. The aim to not puncture the internal leaf.

Gregwor wrote:If you've determined you need the isolation provided by a room in a room, you will need a silencer box on both your inner and outer leaves, both for supply and return. That's a total of 4 silencer boxes.

What size of fan? I see you haven't designed your silencer boxes yet, but make sure it will move x amount of air under x amount of static pressure imposed by your silencer boxes.

I may not have room for 4 silencer boxes, can 2 suffice?

Is there a go to guide on this topic I can go to on sizing these?

Gregwor wrote:Please show us the calculations so we can ensure you're getting the right unit.

The Heat pump was specced by the engineer who came to visit. What calculations should I ask to see?

Gregwor wrote:Your supply and return have to be at the opposite ends of your room. They can penetrate your leaves near one another, but in order to actually work, they need to be as far apart as possible.

POST OVERVIEW AND QUESTIONS (the starred points are edits made after research)

- Can I have both Silencer boxes at one end of the room?
* Could I then run ducting from one of them to the other side of the room?
* Would it be reasonable to run some kind of rectangular ducting in the internal room from where the silencer box will penetrate the inner leaf to the other side of the room
* Thus creating inlet and exhaust vents at either end of room
* Could this ducting be done at low level, say below the proposed work tops, so I don't lose floor space?
* Would it be better to run the exhaust or inlet over this extra distance

- Sound level meter is on the way, figures to arrive shortly

- What is a suggested floor make up?
* My initial thoughts are to use a liquid DPM, then a levelling compound to create the hard surface to build from.
* I can then lay thermal insulation boards > final floor finish

- How could I fill the gap around the current fire door?
* Could I use this kind of putty to fill the gap? - https://bit.ly/2FAIxcj
* It appears to be fairly dense at 1,7 – 1,8 g/cm3
* I haven't handled the product above for the proposed purpose. Is there a tried and tested alternative to these kind of products?
* Would a cement/mortar mix with a plasticising agent like Hydrol added for flexibility to prevent cracking due to movement in the door frame suffice?

- Ventilation still seems tricky to get my head around, but I'm getting there. ( I hope)
- Is there a maximum amount of turns I can make in the box, maximum box dimension based on the room size etc etc?

Thanks you so much again, I look forward to hearing more of the forum member's thoughts on the project. I'll keep plugging away, and sharing as I progress!