Making an old barn soundproof: am I on the right track?

[jaapgvk]

Hello everyone,

I'm new here. My name is Jaap and I'm from the Netherlands. I've never built a studio before, but my (rock)band needs a place where we can practice without being a burden to anyone, so we need the best soundproofing we can get for our budget (about 6000 euro's, but it's not a hard limit).

We can use an old barn that's pretty crappy, but we'll just have to make do. I've been reading a lot on this forum and also read Gervais' book. It's a lot of information to take in, but I'm willing to keep on learning.

The most important thing is sound-isolation. Acoustics in the studio itself don't really matter. We have typical rockband instruments, but we practice with in-ears so the only things that really produce a lot of sound are the drumkit and the amps from the electric guitars.

Our goal is that we can practice well into the night but that our neighbors (that live about 20 meters from the studio) can sleep without earplugs. We have never played in the barn. I have no idea about sound levels. But the walls are badly constructed and even have holes in them. It's just a field barn, kinda.

My main concern is with the existing structure and what to do with it. The barn has the following dimensions:
Width: 5,45m (17,9 ft)
Length: 6,55m (21,5 ft)
Height of walls: 2,9m (9,5 ft)
Top of roof: 4,70m (15,4 ft)

tn_studio outside.jpg

tn_muziekgebouw 02.jpg

PS, the structure will be adjusted so that the horizontal beam you see in the sketchup can be removed.

The owner of the barn is our drummer, and he wanted to isolate the entire roof with 15 cm thick so called 'unidek isolation plates' (which he got for free), which consist of an EPS core with plasterboard attached on two sides. Above that are asbestos roof elements.

tn_unidek2.png

The walls are (also) problematic I think. They consist of normal brick wall on two sides (with a small space of air between them (I'd guess a couple of cm's). One side is a concrete brick wall (one 'layer' thick). And the other side is basically a giant thin steel door. Also, there are three single layer glass windows.

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So that's our 'starting point'. Basically I have two theories on how to do the construction:

1. Treat the existing structure as our 'first leaf'. Make it as airtight and heavy as possible. Then cover it with rockwool. Then make a 'floating room design' consisting of rockwool and the second lead. (Problem with this, is that there is air between two of the walls. There is also air between the unidek plates and the asbestos.)

twee delen.jpg

2. Leave a lot of space between the existing structure and a completely new two leaf mass-air-mass design. (Problem with this is that basically I will have a three leaf design).

drie delen.jpg

Also: I've been thinking about the floor. The barn had it's own concrete slab (which is about 10 cm thick, with sand underneath). I was thinking that a floating floor wouldn't be necessary. But I would imagine that the inner structure (walls and roof) need to be decoupled from the floor, right?

Is anyone willing to give me some pointers on what the best approach might be? I'm not a technician, just a guy who wants to be able to rehearse with his band without being a nuisance to other people.

[Soundman2020]

Hi Jaap, and Welcome!!

I've never built a studio before, but my (rock)band needs a place where we can practice without being a burden to anyone,

So this is mostly a rehearsal room? Not a control room, or a live room (tracking room)?

The most important thing is sound-isolation. Acoustics in the studio itself don't really matter. We have typical rockband instruments, but we practice with in-ears so the only things that really produce a lot of sound are the drumkit and the amps from the electric guitars.

You should put a number to that, as in "xx decibels". You need to measure how loud you are in side there in a typical session, and also how quiet you need to be. The difference between those two numbers is how much isolation you need.

We have never played in the barn. I have no idea about sound levels.

You'll need to get a proper hand-held sound level meter to measure that. They are not expensive. Around US$ 100 for a decent one.

PS, the structure will be adjusted so that the horizontal beam you see in the sketchup can be removed.

How will you do that!!!??? That's a structural tie beam! It carries the tensions between the two walls, caused by the weight of the roof trying to spread them apart, and it also carries wind loads, snow loads, and other structural loads. You CANNOT remove that, unless you replace it with something that does the same job. You will need to hire a qualified structural engineer to look at that, and tell you what you can and cannot do.

he wanted to isolate the entire roof with 15 cm thick so called 'unidek isolation plates' (which he got for free), which consist of an EPS core with plasterboard attached on two sides.

That would help a little bit, but not much. The only way to stop sound is with mass: lots of it. Thick, heavy materials.

The walls are (also) problematic I think. They consist of normal brick wall on two sides (with a small space of air between them (I'd guess a couple of cm's). One side is a concrete brick wall (one 'layer' thick). And the other side is basically a giant thin steel door. Also, there are three single layer glass windows.

The brick walls are good: no problem there. The big problem is that large metal door. The windows are a smaller problem, that is easier to deal with, but that door is a big problem. So is the roof.

1. Treat the existing structure as our 'first leaf'. Make it as airtight and heavy as possible.

Yes! You will need your structural engineer here to, to tell you how much weight you can hang from that roof. It does not look like it has much extra capacity: you will probably have to beef up the structure, so that it can carry the weight that you will need.

Then make a 'floating room design' consisting of rockwool and the second lead.

I think you meant "second leaf" not "second lead", but yes, that's the right idea.

(Problem with this, is that there is air between two of the walls. There is also air between the unidek plates and the asbestos.)

Are you SURE that is asbestos? In most countries, asbestos is illegal as a construction material these days. If that really is asbestos from a very old build, you might find that you will have to call in a hazmat company ("hazmat" = "hazardous materials") to remove it safely and dispose of it, as it is a health hazard. Hopefully, it isn't really asbestos and just looks like it. It might be fiber-cement board that does not contain any asbestos, in which case it is fine. Check your local building codes and laws, to find out if you have a problem. Do not try to remove it yourself: it is dangerous stuff.

2. Leave a lot of space between the existing structure and a completely new two leaf mass-air-mass design. (Problem with this is that basically I will have a three leaf design).

Not a good idea! Overkill, very expensive, and not necessary.

Also: I've been thinking about the floor. The barn had it's own concrete slab (which is about 10 cm thick, with sand underneath). I was thinking that a floating floor wouldn't be necessary. But I would imagine that the inner structure (walls and roof) need to be decoupled from the floor, right?

The slab is great! Excellent! No floating floor necessary. And no, you do not need to decouple the walls from the floors. You do not need extreme isolation, so that isn't necessary.

Is anyone willing to give me some pointers on what the best approach might be? I'm not a technician, just a guy who wants to be able to rehearse with his band without being a nuisance to other people.

I would go with a "hybrid" design there. You cannot isolate that roof, as it is clearly designed to be ventilated, so you cannot but insulation and other materials under the roof deck. Leave it as it is, and build a new "middle leaf" ceiling below it, with framing and plasterboard. Then build your "inner-leaf" room inside of that new shell. Don't block off the ventilation to that roof, and don't put insulation next to it, or you will end up with condensation problems, and mold, mildew, etc.

- Stuart -

- Stuart -

[jaapgvk]

Hi Jaap, and Welcome!!

Hi Stuart, thanks so much for taking the time to reply! I wasn't expecting a reply to this thread anymore

So this is mostly a rehearsal room? Not a control room, or a live room (tracking room)?

You are correct, this will mostly be a rehearsal room. The acoustics don't have priority. We will have a little control room outside of the rehearsal room and will record stuff, but we don't aim on making album-quality recordings here. Of course, if in the end the acoustics end up being okay, I won't be complaining

You should put a number to that, as in "xx decibels". You need to measure how loud you are in side there in a typical session, and also how quiet you need to be. The difference between those two numbers is how much isolation you need.

You'll need to get a proper hand-held sound level meter to measure that. They are not expensive. Around US$ 100 for a decent one.

I will buy a proper sound level meter. In the meantime I think we're aiming at about a 60db reduction in sound.

How will you do that!!!??? That's a structural tie beam! It carries the tensions between the two walls, caused by the weight of the roof trying to spread them apart, and it also carries wind loads, snow loads, and other structural loads. You CANNOT remove that, unless you replace it with something that does the same job. You will need to hire a qualified structural engineer to look at that, and tell you what you can and cannot do.

Haha! I know. It's quite shocking. It's been more than a month since I started this thread, and in the meantime I consulted a structural engineer (who also happens to be my father :p ). According to his suggestions, we're making two adjustments to the roof construction.

1. We will weld another tie beam a bit higher up.

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2. We will stud the roof a couple of feet further on (where the outer wall of the studio will be).

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That would help a little bit, but not much. The only way to stop sound is with mass: lots of it. Thick, heavy materials.

Yes, you are right. That's why we've decided to put an extra layer of plasterboard on there. The total weight of the outer leaf will become about the same as 30mm of plasterboard.

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The brick walls are good: no problem there. The big problem is that large metal door. The windows are a smaller problem, that is easier to deal with, but that door is a big problem. So is the roof.

Again, I fully agree with you We've decided to remove the door and replace it with a construction which consists of a layer of heavy wooden plates and 25mm of plasterboard.

Are you SURE that is asbestos? In most countries, asbestos is illegal as a construction material these days. If that really is asbestos from a very old build, you might find that you will have to call in a hazmat company ("hazmat" = "hazardous materials") to remove it safely and dispose of it, as it is a health hazard. Hopefully, it isn't really asbestos and just looks like it. It might be fiber-cement board that does not contain any asbestos, in which case it is fine. Check your local building codes and laws, to find out if you have a problem. Do not try to remove it yourself: it is dangerous stuff.

Unfortunately, it is indeed asbestos. Here in the Netherlands it has been illegal for many years, but this is an old building. Before 2020, all asbestos has to be removed in the entire country. The problem is that this barn is one of many on this farm which has asbestos roofs, and they want to do all buildings in one take (has to do with subsidised removal).

So in the meantime we'll have to leave the roof as it is.

The slab is great! Excellent! No floating floor necessary. And no, you do not need to decouple the walls from the floors. You do not need extreme isolation, so that isn't necessary.

I will follow this advice Thanks!

I would go with a "hybrid" design there. You cannot isolate that roof, as it is clearly designed to be ventilated, so you cannot but insulation and other materials under the roof deck. Leave it as it is, and build a new "middle leaf" ceiling below it, with framing and plasterboard. Then build your "inner-leaf" room inside of that new shell. Don't block off the ventilation to that roof, and don't put insulation next to it, or you will end up with condensation problems, and mold, mildew, etc.

- Stuart -

Thank you for your advice. Really appreciated!

Since it's over a month ago since this thread was started, we've been doing some work in the meantime. But thankfully, we did almost everything as you suggested

materiaal.JPG

We ordered a lot of stuff already: plasterboard, wood for the construction of the inner leaf, and hardwood for the door frames. We also have enough fibreglass (22kg/m3) to fill the entire cavity between the leafs.

We did end up making a sort of hybrid system. The asbestos roof is 'floating' above the outer leaf. The outer leaf consists of the aforementioned 'unidek isolation plates and plasterboard' combination. If I could start the project again, I would've left out the isolation plates and would just have used plasterboard to create the outer leaf. But since our drummer went ahead and installed the plates anyway, we just have to work with that. But all in all I think the project is going along nicely.

Our next 'thing' is how we will get the cables from the control room to the studio. We were thinking about routing the cables through the ventilation systems baffle boxes.

O, and the control room will be outside of the room we're isolating (we decided this after starting this thread). On the other side of the wall which we used for the roof studs:

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(darkblue = doors
lightblue = windows)

We'll use very heavy laminated windows between the two rooms:

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The tracking room won't be needing nearly as much sound isolation than the rehearsal room, so we decided we'll have more room this way.

[Soundman2020]

Of course, if in the end the acoustics end up being okay, I won't be complaining

The acoustics can be great in that room! Just no good for a control room. Or the acoustics could be made perfect for a control room... which would be terrible for a rehearsal room. That's the issue. Control-room acoustics and live-room acoustics are two very, very different things. The control room must be perfectly flat, perfectly neutral, perfectly diffuse, highly controlled.... which is a lousy environment for musicians to play in, or to track in. And the typical bright, warm, lively acoustics of a good tracking room or rehearsal room would make it impossible to mix well in there. These are two opposing sets of requirements.

I will buy a proper sound level meter. In the meantime I think we're aiming at about a 60db reduction in sound.

60 dB is about the limit of what you can get in a typical home studio on a good budget. The flanking limit is probably around 70, with a bit of luck, but it's really hard to get that high: you'd need to spend big money to accomplish that.

1. We will weld another tie beam a bit higher up.

So you are going to convert your trusses into raised-tie, or collar-tie? That's fine, as long as you have a structural engineer guiding you.

2. We will stud the roof a couple of feet further on (where the outer wall of the studio will be).

.... which is basically the same as adding king-posts to some of your trusses. Good. I would have probably replaced the ridge beam with something more substantial as well, supported at both ends on new pillars, but I'm a bit if a "belt and braces" guy, given where I live. I tend to over-design structures, since the ground over here has a bad habit of shaking the daylights out of you every now and then! Were you live, you don't get earthquakes, so your solution is probably fine.

That's why we've decided to put an extra layer of plasterboard on there. The total weight of the outer leaf will become about the same as 30mm of plasterboard.

Excellent, but is that spray foam I see in the joints between your drywall sheets? It sure looks like you have used the typical "foam in a can" expanding polyurethane foam in there...

spray-foam-eror.jpg

If so, you MUST get that out and replace it with a suitable caulk. That foam is is very low density, very brittle, and no use at all for what you are trying to use it for. It will seal the gaps, yes, but that's not the point: You need to seal the gaps WHILE ALSO MAINTAINING THE MASS CONTINUITY. With that foam in there, you do not have the equivalent of 30mm of drywall: you have the equivalent of half of that. You are severely compromising the isolation. Cut that foam out from all the joints, and either "mud and tape" it in the typical manner, or caulk it with suitable caulk.

This is VERY important. A big mistake.

the control room will be outside of the room we're isolating (we decided this after starting this thread).

That's the correct way to do it: each room must be isolated by itself: They can all be built inside the same single outer-leaf, yes, but each must be built as its own individual, separate inner-leaf.

What are the dimensions of the control room? It looks very small on your diagram...

(darkblue = doors
lightblue = windows)

So it looks like you are not going to isolate the control room AT ALL???? Why not? In your first post you said: "The most important thing is sound-isolation." Yet your control room will not be isolated? That does not make a lot of sense....

The tracking room won't be needing nearly as much sound isolation than the rehearsal room,

Tracking room??? What tracking room? You didn't mention any tracking room up to now. You only mentioned the rehearsal room and the control room, but no tracking room. Where will the tracking room be? Is that something additional that you plan to build later? And why would a tracking room not need isolation, when it is basically the same as a rehearsal room?

I'm just a little confused about what is going on here. On the one hand you say that you need high isolation, but then you keep showing things that are not high isolation at all... You say that you want to keep the costs down, but then you do things that are wasting money and time (like using foam between the drywall joints). I'm wondering if there is any real detailed plan here at all, or if you guys are just sort of making it up as you go along... For example, I see no provision at all for HVAC, which is a major part of any studio, and very hard to do once the basic structure is completed. Much easier (and much cheaper) to do it before and during the basic structure... I wonder what other issues might have been forgotten...

- Stuart -

[jaapgvk]

Yeah, I guess I have to clarify myself on a few point here.

First off: I got confused about some terms: there will just be a rehearsal room and a control room. I called the control room a tracking room by mistake.

Second: you're right about the control room having not nearly as much isolation as the rehearsal room. This is because of practical reasons from the point of view of construction possibilities regarding the outer leaf. But it won't be a 'real' control room, just a room where the computer and mixer will be, and where people can sit outside of all the loudness when we want to record some music. Acoustics won't really matter here because there won't be any mixing done in this room, and there won't be any loud noises generated there.
And to answer your other question: yes it's very small. I don't know the exact measurements, but it's tiny :p

So you are going to convert your trusses into raised-tie, or collar-tie? That's fine, as long as you have a structural engineer guiding you.

I would have probably replaced the ridge beam with something more substantial as well, supported at both ends on new pillars, but I'm a bit if a "belt and braces" guy, given where I live. I tend to over-design structures, since the ground over here has a bad habit of shaking the daylights out of you every now and then! Were you live, you don't get earthquakes, so your solution is probably fine.

I think it's not a bad idea to over-design stuff Thankfully we have a structural engineer that knows what he's doing. I think it's called a collar-tie (I'm not familiar with the English construction names). At the moment everything is already welded in place.

Is that spray foam I see in the joints between your drywall sheets? It sure looks like you have used the typical "foam in a can" expanding polyurethane foam in there...
If so, you MUST get that out and replace it with a suitable caulk. That foam is is very low density, very brittle, and no use at all for what you are trying to use it for. It will seal the gaps, yes, but that's not the point: You need to seal the gaps WHILE ALSO MAINTAINING THE MASS CONTINUITY. With that foam in there, you do not have the equivalent of 30mm of drywall: you have the equivalent of half of that. You are severely compromising the isolation. Cut that foam out from all the joints, and either "mud and tape" it in the typical manner, or caulk it with suitable caulk.

This is VERY important. A big mistake.

I think you can disregard the foam that's hanging there. That's just some leftover. It's true that we've used foam, but just to fill up some cavities in the roof construction. Nowhere in the the construction have we used it to seal joints or gaps: that's all done with massive amounts caulk and plaster as you can see here:



I just figured it would be better to fill cavities with foam then to have spaces of air (because the foam is closed-cell so there wont be any multiple-leaf problems).

After that, we've installed the final layer of drywall:

I'm just a little confused about what is going on here. On the one hand you say that you need high isolation, but then you keep showing things that are not high isolation at all... You say that you want to keep the costs down, but then you do things that are wasting money and time (like using foam between the drywall joints). I'm wondering if there is any real detailed plan here at all, or if you guys are just sort of making it up as you go along... For example, I see no provision at all for HVAC, which is a major part of any studio, and very hard to do once the basic structure is completed. Much easier (and much cheaper) to do it before and during the basic structure... I wonder what other issues might have been forgotten...

- Stuart -

I hope to have convinced you that the choices we've made were not without giving it any thought, and are the result of practical possibilities and the existing structure we have to work with. If you still have reservations then I'm very open to feedback!

There are also plans for HVAC, and that will probably be the next stage of construction. Right now I'm working on the plans for the baffle-boxes.