Shed studio conversion

Hi, So after a little thinking, convincing and concern of my limited construction abilities, I started my shed conversion a few years ago. I thought it would only take 6 months. 2+ years and 2 children later - I'm still going! The house we had bought some 3 year prior had a significant shed and the idea was to convert it to a visual art / music studio. The idea was to first make one big room and then put a small room in the rear for a recording studio, allowing space for storage and an art studio. I started by fixing up the 30 year old shed... cutting out rust, sanding, spray painting etc. I quickly realised that the condition of the concrete foundation was rubbish so I ripped out the concrete slab and put a new one in. The pictures probably tell more than 1000 of my words. Questions - just ask! To give you an idea, the shed is around 5x12m. reasonable size. With the new ceiling, the height is around 2.7m. As mentioned before, I'm aiming to build two rooms and also have some room for storage. The two rooms will be roughly similar in size, one room my recording studio, and the other - a visual art studio. So I put in insulation new power, data, insulation, drywall (13mm), plumbing for 2 ac, cornice etc. Most importantly I sealed everything up. I probably stupidly didn't know very much about studio building when I started. I was relying on the advice of one individual - good advice, but myself, I had never done anything like this. I have been waiting for my brains trust to produce a design for me to progress however apart from a few conversations, this never got off the ground. I proceeded to read a couple of books, this forum and basically anything that helped me to join a few dots. I have now put together a plan however I have a few questions that I would appreciate advice. Firstly, my brains trust gave me some advice. He suggested having a slightly smaller room to improve the room acoustics. In combination with this information and the attempt to make construction as straight forward as possible - I'm working on a internal dimensions of: 5.65x3.6x as high as I can make it. So the plan was always to have the art studio at the front (basically done) - and build a room inside a room studio. So what do I want to achieve... 1) the best result I can on limited budget and space 2) for the majority of the time, the studio will only be used by me. I am a multi instrumentalist... Drums, Guitars, keys... etc. 3) I have young children so isolation is as much for my own family as it is for neighbors. 4) I don't expect to produce anything that will reach significant radio rotation - but I expect to produce good production. The biggest issue has been designing the ceiling. Before I began reading, we had come up with a inside out ceiling design. Basically we came up with the idea of modules - framed. We came up with the idea of skinning the whole room with two layers of 19mm tongue and grove. The idea uses 3.5x90mm structural timber. Essentially, each module would be lifted up, bolted together and sealed. Each module would then be filled with Tontine acoustisorb 3. To finish off, either fabric straight over beams or building small frames. A lot of the wall design aims to maximise the space in the room and also to enable the easy addition of treatments (tontine). To do this, I plan on putting the MDF sheets on the outside of the walls (for three of the 4 walls). To do this, two of the walls will need to be constructed on the ground and then lifted up - Amish style... With two layers of MDF, this will be heavy. I suspect I will need to design the walls in sections. Given the forum will not allow any more attachments, I'll leave sketch-up to tell the rest of the story! So the questions: 1) I notice that not too many people use two layers of mdf. Are there problems with using two layers of mdf rather than some other combination? 2) Any suggestions / concerns with the ceiling design? 3) Are there problems with using a combination of inside out and normal wall construction? 4) What potential room sealing issues do I have and can I improve the design somehow? That will probably do for now. Cheers,

Hi there "wofftech", and Welcome! :)

I quickly realised that the condition of the concrete foundation was rubbish so I ripped out the concrete slab and put a new one in.

Great! so you have your studio floor issue resolved already: concrete is about the best possible floor you could hope for, and is also great for isolation. Image-3 shows what seems to be a stud frame built just inside the skin of the building, and following images show that stuffed with insulation, the drywalled. So you already have a two-leaf isolation system in place... Building anything within that, would make it a three-leaf isolation system, which implies poor isolation in the low frequencies... unless you can spare a lot of extra space for the third leaf, and afford the extra mass that you will need to compensate for the 3rd leaf effect. It's a pity you didn't find the forum before you did all that!

drywall (13mm),

:shock: That's not going to be good for decent isolation. You don't say how much isolation you need (in decibels), but since that 13mm drywall is your middle leaf, and optimal isolation in a 3-leaf system is achieved only with half of the total mass on the middle leaf, that doesn't bode well for high isolation...

He suggested having a slightly smaller room to improve the room acoustics.

That's unusual advice! In general, larger rooms have better acoustics, and smaller rooms have worse acoustics. Unless there was an overriding reason for making the room smaller (for example: if it would have been a cube or square otherwise, or have a really bad ratio), then the general recommendation is to make it as big as possible. Do you know WHY your friend suggested making it smaller?

5.65x3.6x as high as I can make it.

for those dimensions, 2.5 to 2.6m is about optimal. Definitely no more than 2.65, nor less than about 2.45. At 2.6 H, you could take the length up to about 6.1 if you felt like it. And with those two held constant (2.6 and 6.1) you could take the width up to about 4.20. There are better and worse combinations in that range, but overall there's some good ones, and plenty of options to play with. Assuming this is for a control room, that is? Or a one-room studio that is basically a control room with built-in tracking/rehearsal area?

Drums,

Acoustic or electronic? Assuming acoustic, that implies a lot of isolation.... but we'd need to knwo how much, to help you design the isolation system.

3) I have young children so isolation is as much for my own family as it is for neighbors.

How far away is your family? How far away are your neighbors? What are the legal requirements for noise in your area? How many decibels of isolation do you need?

we came up with the idea of modules - framed. We came up with the idea of skinning the whole room with two layers of 19mm tongue and grove. ... The idea uses 3.5x90mm structural timber.

30 kg/m2 dead load, spanning 3.6m, on 2x4 lumber? Hmmmm... did you check that with a structural engineer? What deflection did you want for that, and what spacing are you using for the joists? To be very honest, that doesn't sound safe! I doubt you could do that with anything less than 2x8 joists, or maybe 2x6s if you could get good lumber (oak, hemlock, spruce, etc.) and were prepared to live with large deflection. But on ordinary pine or fir, I don't see that passing inspection on 2x4s. Where I live, it would have to be at least 2x8s 40cm OC, and L/480, minimum. You really should double-check that with your engineer. Also, that low mass ceiling with the light-weight middle leaf and thin flexible outer leaf, does not sound like a good combination for low frequency isolation. Are you sure that's what you need? You did mention "drums", "neighbors" and "family"...

Essentially, each module would be lifted up, bolted together and sealed.

The idea is OK, but the joist sizes, mass, 3-leaf system, and isolation are not very convincing. I don't see you getting much more than 40 dB of isolation overall, and substantially less in the low end.

Each module would then be filled with Tontine acoustisorb 3.

Yes, but that's underneath, which is inside the room, so that is treatment, not isolation. You also need damping (insulation) on top of that, to deal with the multiple resonance that will be going on inside the MSM cavity...

With two layers of MDF, this will be heavy. I suspect I will need to design the walls in sections.

Or use wall jacks... Not sure if you have the space for that, but if you work carefully you should be able to do it.

1) I notice that not too many people use two layers of mdf. Are there problems with using two layers of mdf rather than some other combination?

The issue is mainly cost: In most places around the world, drywall (plasterboard) is a lot cheaper than MDF, and the mass (surface density) is similar, so using drywall tends to be cheaper. MDF isn't great structurally either. So another option might be to put a layer of OSB on first as your base layer (against the studs) then a layer of 16mm fire-rated drywall for the second layer.

2) Any suggestions / concerns with the ceiling design?

Structural. See above comments...

3) Are there problems with using a combination of inside out and normal wall construction?

Nope! None at all. As long as you are certain that about your mass continuity all around the room, and that you have figured out how to get good seals where the two meet, then there's no problem with doing it that way. Interesting project! I'm looking forward to following along. - Stuart -

Cheers Stuart for your rely - appreciate it! I've read you post a number of times now! Clearly I have some issues I need to work through! In regards to the concrete floor, my plan is to leave it exposed (painted) and leave it at that. Are there any issues I need to consider doing this? The metal shed itself is not sealed so while I did my best to make it water tight - replacing components of the metal roof etc - it's no sealed skin – and can’t be by design. The wooden frame is largely completely separate from the metal shed frame. From memory, some of the metal joists were used to help support the ceiling. My brains trust encouraged me to put two layers of drywall up however I didn't totally understand why this was important at the time + the one layer of drywall was already significant in cost. My plan is to leave a reasonably significant gap right around the music studio - 15 - 20 cm. I've been told that the air gap is important. Any further guidance would be appreciated. The room size that was suggested to me was at first surprising. While the shed is large, splitting it in two would create 2 near square rooms. I'm not going to pretend I understand acoustics, but as you suggested, squares are something to keep away from. The dimensions do make things like the ceiling easier as it means that mdf flooring sheets could fit straight across without any further cutting or joining given they come at 3600. The extra space will become handy to store my growing guitar collection :-) I've come to the realisation that the small size is a limitation but it will give me a space to produce music. I've looked at a few room calculators and the dimensions given look quite good. In the time being, I'll look at what extending the length looks like. In terms of studio use and isolation, I'll be using electric guitars the most and then plenty of programing. I may look at building a small isolation cupboard outside of the studio to add some flexibility. I started life as a drummer so I like the idea of occasionally recording acoustic drums but would think it'll only be a monthly accordance at most. I can also expect to be recording vocals and acc guitars. To give you an idea, I recorded an album worth of load electric guitars in the shed before I started with this project and I am still talking to my neighbors. Whatever I do will be a massive improvement! It's really hard to say how much isolation I want achieve. I don't want to say something ridiculous and unachievable. In may respects, budget is a big factor. I'm trying to do the best I can with limited budget. I started like most people thinking - I could do this for all for $10k. Nearly 20K later and I have not built my studio yet. Let this be a lesson to anyone reading this and thinking about doing a shed conversion, 10K will not get u far! The ceiling is the thing that has been the big problem. I sent the plans to my builder for feedback today but I'm not confident. From memory, I proposed 600m beam spacing (including a complete module frame). When I was putting the plan together, I've seen the following design talked about but I can't get my head around applying it and have concerns with ease of construction. 1) in my mind, the above plan seems it would be very difficult to seal effectively as the beams would need to be further enough apart to lift up the panels up but snug enough to not produce gaps – clearly it has been done a number of times – maybe I’m just not understanding things properly. 2) If corking can be done to solve sealing issues, It seems similar to what I am suggesting - just with structural beams going in between each ceiling module. If my current design is not considered structural (and I agree with you that I doubt it), I could redesign the module a little to accommodate larger structural beams. What I’m thinking is have a 120 or 150 joists between each ‘panel’. I wouldn’t need to overlap sheets obviously – making yellow tongue no long as beneficial. The benefit I see in this proposal vs other inside out design is it would be a heap easier to put up. I could easily use a couple of dry wall lifters and lift them up on the walls. With this new idea, the structural beam could then slide into the frame – ie building the ceiling and frame as you go. I’m really at a loss here so any suggestions are welcome. There was real benefit for having the room at 3600 given this can be a full sheet of mdf – not sure about SBP. I like your idea re SBP and dry wall. With an inside out ceiling design, I would imagine the SBP be on the inside of the studio? are there any acoustic benefits for going this way? Would I be looking at using a special type of insulation on the back of the walls / ceiling? Does thickness matter? I would imagine glue could be used for attachment or are their other methods? I read this somewhere on a post ages ago but given my brains trust didn't mention it, I paid no attention. Given you suggested the current design has significant limitations re isolation, is there anything I can do now to improve things or an I stuffed due to the method of construction I have already adopted? Thanks coming along on this journey with me!

I got feedback from my chippy who was so so re the original design and suggested some brascing. So I have had a look at redesigning the ceiling. It is essentially the idea what is talked about within the forum here. The idea would revolve around putting up a panel, then a beam, screwing the beam to the panel, seal, move on. The big concern I have is sealing between the panel frame and the 15cm beam. Because there is on overlap with the boards anymore, I would think this would be quite weak re sealing. Any advice would be appreciated. While I got told that ventilation was going to be too hard to deal with, after reading the forums, I realise I need to deal with it. While I have a ac planed, I need to get fresh air in and out... After reading the posts... I'm guessing a couple of fans, and silencer?

The idea would revolve around putting up a panel, then a beam, screwing the beam to the panel, seal, move on.

That should work, yes. Just make sure that the beam is dimensions correctly for the span! Do get a certified structural engineer to sign of on that.

The big concern I have is sealing between the panel frame and the 15cm beam. Because there is on overlap with the boards anymore, I would think this would be quite weak re sealing. Any advice would be appreciated.

Acoustic caulk, applied liberally. Lots of it! Apply in every possible place you can think, of during the building of the modules, also as each one is installed, and once again after they are all in place.

I need to get fresh air in and out... After reading the posts... I'm guessing a couple of fans, and silencer?

Yep. You only really need one fan per room: since the room is basically an air-tight container with a inlet duct and and exhaust duct, if you on the exhaust duct that that automatically also sucks fresh air in through the intake duct. - Stuart -