rehearsal space in existing tin shed

[neilstar]

hello all, my name is Neil i live in Adelaide South Australia

i have just moved into a new house with a tin shed 12m long x 6m wide x 2.1m high at the gutter and has a pitched roof, 100mm concrete slab, electricity, power and lights, its 30mm steel square tube construction, basic frames with 70 x 35 timber wall battens and roof joists with a corrugated iron roof and flat zinc sides as walls, my basic plan is to use the back half of the shed to build a room within the shed that is as soundproof as possible for rehearsing in, guitars, drums, bass, vocal PA, approx 100db if not more, i have read lots of different topics on this forum so before i begin any construction inside shed i thought i may as well ask some questions, i realise that tin shed is not ideal,but its all i have to work with , i have some of materials, freebies that i have gathered, 2400x1200x18mm chipboard, 2400x1200x10mm gyprock, 2400x1200x16mm plywood, 3600x1200x60mm polystyrene foam, 2400x70x45 timber studs, insulation, 50x13mm thick rubber strips, tubes of silicon caulk, i was planning on building a room within a room inside the shed, disregarding the tin shed basically cause that will do nothing for sound isolation, heres my plan, basically the walls and ceiling exactly the same

outside to inside goes
1=1 layer of 60mm polystyrene foam fixed on to gyprock
2= 2 layers of 10mm gyprock, fixed onto chipboard
3=1 layer 18mm chipboard fixed to 1st timber frame
4=1st timber wall frame 70x45 on top of some 50mm rubber strips dynabolted to floor 600 between centres for wall studs filled with standard pink batt insulation
5=2nd timber wall frame(same construction as above) spaced 300mm??? inside 1st wall frame, rubber strips, dynabolted to ground filled with insulation
6=1 layer 18mm chipboard screwed to frame, maybe run a bead of caulk along each wall stud
7= 2 layers of 10mm gyprock, all fixed staggerd to chipboard with caulk
8=1 layer of 60mm polystyrene foam

1st ceiling mounted onto the outside wall, is pitched the same as shed roughly
2nd ceiling mounted onto the inside wall , same as wall space 300mm lower than the outside ceiling

using a double door setup to enter the room, 2 solid core doors opening opposite directions,

for the floor i was thinking of timber joists 70x45 400 between centres sitting on 13mm rubber strips with insulation between joists, then a layer of chipboard screwed down, then underlay then a layer of plywood, then use carpet in sections , eg under drum kit,
or i just use carpet underlay straight onto concrete then 2 layers of 16mm plywood or maybe even covering the entire floor with 60mm polystyrene then the carpet underlay then 2 layers of 16mm plywood,

there will be no windows, but i will need to think about ventilation or an airconditioner

any help thoughts would much appreciated , or am i wasting my time and money trying to this in a tin shed, not expecting total isolation, but some would be good so i could play drums or guitar and listen to music at night if i wanted too

thank you Neil

[Soundman2020]

Hi Neil, and welcome!

That's a nice sized shed, but as you already figured out, not much use for isolation by itself. There also doesn't seem to be any easy way to beef up that tin, and in any case, the structure doesn't look like it can take the amount of mass that you'd need. So it seems that your only choice is to build a three-leaf studio, with that shed as the outer leaf.

i have some of materials, freebies that i have gathered,

Some of those are useful, some not:

2400x1200x18mm chipboard

Probably useful, depending on what type of chipboard. Got details? Specifically, what density is it?

2400x1200x10mm gyprock

Not useful: way too thin. Recommended thickness is at least 16mm, and at pinch you might be able to get away with 12.5mm, but 10mm is just way too thin, too flexible, lousy resonance characteristics, etc.

2400x1200x16mm plywood

Excellent! Very useful.

3600x1200x60mm polystyrene foam

No use at all acoustically. Polystyrene is closed-cell, which makes it do nothing at all for acoustics. You need only open-cell insulation, such as fiberglass or mineral wool.

2400x70x45 timber studs

That's basically equivalent to a 2x3. Might be useful in some places, but not for the actual structure. You'll need minimum 2x4 studs (40 x 90mm) for the walls, and at least 2x6 (40 x 140mm), more like 2x8 (40 x 184mm) or 2x10 (40 x 235mm) for the ceiling joists. Maybe even more. You are going to be adding huge amounts of mass to the walls and ceiling, so the structure has to be able to support that safely. 2x3s are not up to the job. You can use them in non load-bearing parts, and for things like building your acoustic treatment devices, soffits, risers, etc., but not for the actual structure.

insulation,

What type? Specifically, is it mineral wool or fiberglass, and what is the density?

50x13mm thick rubber strips,

Probably no use, and certainly not in the manner described.

tubes of silicon caulk,

Excellent! You'll need lots of that. As in LOTS! So provided that you have the type that never hardens, and always stays flexible and rubbery, you are fine.

1=1 layer of 60mm polystyrene foam fixed on to gyprock
2= 2 layers of 10mm gyprock, fixed onto chipboard
3=1 layer 18mm chipboard fixed to 1st timber frame

The polystyrene has no acoustic use here. Fine for thermal insulation, but zero effect acoustically, and since that cavity is part of your three-leaf MSMSM system, it does need to have acoustically useful insulation in it. Also, the gyprock is of no real value here, for the reasons described above. See if you can get that replaced with 16mm gyprock. Even if you can do a "2 for 1" swap with someone, you'd still be coming out ahead, acoustically speaking.

4=1st timber wall frame 70x45 on top of some 50mm rubber strips dynabolted to floor 600 between centres for wall studs filled with standard pink batt insulation

There's no point to the rubber strips, from the acoustic isolation perspective. The only thing they would be doing there is helping to get a better seal under the framing, if the floor happens to be uneven or in a poor state. They will not make your wall "float", nor provide any decoupling at all, for the very reason you mentioned: "dynabolted to floor". Yes, you do need to do that, but doing so bypasses any isolation the rubber might have been providing otherwise.

5=2nd timber wall frame(same construction as above) spaced 300mm??? inside 1st wall frame, rubber strips, dynabolted to ground filled with insulation

The spacing you need depends on the amount of isolation that you need. A three-leaf wall is a tuned system, tuned to a specific set of resonant frequencies, and you need to tune those according to what your goals are. The way you tune a wall is by adjusting the size of the air gap between the leaves and the amount of mass on each leaf. So that 300mm spacing might be fine, or it might not. You need to define what your isolation goals are, in terms of "xx decibels at yy frequency", then based on that you can use the equations to determine how much mass and what spacing. In fact, you only mention the spacing between the inner and middle leaves: you didn't mention how much spacing you are planning between the middle and outer.

7= 2 layers of 10mm gyprock, all fixed staggerd to chipboard with caulk

Not sure what you mean by "fixed ... with caulk", but that sounds like you intend to use the caulk as adhesive? To sort of glue the gyprock to the chipboard? Nope. You cannot do that. There's no acoustic benefit to doing that, and it is simply unsafe. The gyprock must be nailed or screwed into the studs, though the chipboard. You cannot glue layers of wall together, and even if you could, doing so would be detrimental to the performance of the wall, not helpful.

8=1 layer of 60mm polystyrene foam

Once again, no use at all. Polystyrene is closed-cell, meaning that air cannot penetrate and move through it, so it is totally useless for acoustics. Only open-cell insulation can be used: mineral wool and fiberglass are best. Proper acoustic foam also works, of course, provided that it really is acoustic foam, and provided that you have lots of spare money. Packing foams and upholstery foams are also useless.

1st ceiling mounted onto the outside wall,

So you are NOT going to do a three-leaf system then? In order to have a true three-leaf system, you would have to have a "middle" ceiling suspended between the inner ceiling and outer one (the roof) by some type of isolation mounts. The easiest would be to just put scissor trusses on your middle-leaf framing, and attach gyprock to that.

for the floor i was thinking of timber joists 70x45 400 between centres sitting on 13mm rubber strips with insulation between joists, then a layer of chipboard screwed down, then underlay then a layer of plywood,

Why? You already have a perfectly good, very massive, very well damped, excellent acoustic floor: the concrete slab. Why would you want to make that worse? All you would succeed in doing, is to create a resonant cavity below your floor, which would wreak havoc with the room acoustics. You cannot float a floor like that, and trying to do so would be a big mistake. And I don't see any reason why you would eve nneed to do that: you didn't mention anything at all about low frequency vibrations, or other reasons why a floating floor might be needed.

or maybe even covering the entire floor with 60mm polystyrene then the carpet underlay then 2 layers of 16mm plywood,

Once again, the polystyrene is no use at all in that application. It has no useful acoustic properties. Just like egg-crates and carpet, it is a myth that polystyrene can do anything beneficial to a studio: it cannot.

or i just use carpet underlay straight onto concrete then 2 layers of 16mm plywood

Is there something wrong with the concrete? It seems to be in great condition from the photo, so I don't understand why you don't want to use it just like it is. There's no better surface, acoustically, if the rest of the room is treated correctly. If you happen to dislike the look of concrete, then just lay some type of laminate flooring on suitable underlay design for laminate flooring. That's all you need. There are some really nice looking laminates these days. Or if you don't like laminate, then use ceramic tiles, or even linoleum. There are very attractive options for both of those.

there will be no windows

That makes it a bit easier.

, but i will need to think about ventilation or an airconditioner

Actually, you will need both! The air conditioner takes care of keeping the room cool and suitably dehumidified, but you still need to bring in fresh air, and exhaust stale air. There are equations for calculating how much fresh air you need, and what size air conditioner you need, based on room occupancy, local climate, equipment, lighting, room volume, etc. so you'll need to work through those equations to come up with the correct sizing for your HVAC ducts, fans and dampers, and correct sizing for the air conditioner unit itself. Mini-split systems are the best for studios, in general. Simple, efficient, and quiet.

or am i wasting my time and money trying to this in a tin shed, not expecting total isolation,

Not wasting money at all! If that's the space you have, then that's what you have, and it can be converted into a very nice rehearsal area, if done correctly.

- Stuart -

[neilstar]

WOW , thank you soundman for your time and effort of going through, reading and giving yr thoughts on what i have been planning, much appreciated
i am in no hurry, and i want to do it properly, best i can for a shed, the materials i have been gathering were freebies i thought i could use doesnt mean i have too, after reading lots of different posts on here i was beginning to realise that i was on the wrong path and have to change my plans if i want it to be as good as possible, i will be going through your post and answering as many questions as possible, thank you once again Neil

[neilstar]

Hi Stuart,

thank you once again for taking the time to read and reply in such detail,

i was wondering your thoughts of lining the internal walls and ceiling of the tin shed with 60mm polystyrene foam, i understand it will do nothing for sound isolation and im sure the structure will handle that at least as its very light and i think it would be a good thermal insulation material against the hot and cold weather ??? i added a picture of a piece installed on the wall and ceiling.

Chipboard 2400mmx1200mmx18mm how can i work out what specific type of chipboard it is, i added a photo? and it weighs 37-38 kilograms per sheet?

10mm gyprock? this may seem like a dumb question but 2 layers of 10 mm gyprock totalling 20mm thickness not better than 1 layer of 16mm gyprock ?

insulation batts 3 options
1. R1.5 Knauf Earthwool Insulation. 580mm x 1160mm x 75mm thick
2. R2.5 HD (High Density) Knauf Earthwool Insulation 580mm x 1160mm x 90mm thick
3. R4.0 Knauf Earthwool Insulation 580mm x 1160mm x 195mm thick
they are all low irritant fibreglass batts which one would be best, if not can you recomend which type of insulation i should use


you mentioned isolation goals? im really looking at building a room that i could play a drumkit in and maybe a guitar amp at the same time, approx 100 decibels max, im assuming i dont go over that regurlarly as i would be going deaf, but would like to isolate sound as much as possible within a tin shed,

2 spaces 300mm spacing between the polysterene foam walls and ceilings to the outside of the middle wall, then 300mm from the inside of the frame of the middle wall to the outside of the internal wall, mmm i hope that makes sense????

Question regarding ,a true three-leaf system, you would have to have a "middle" ceiling suspended between the inner ceiling and outer one (the roof) by some type of isolation mounts.please explain ceiling suspended? some type of isolation mounts?

i was going to fix it to the top of the middle wall?

concrete floor is flat and healthy, floating floor gone, i will concentrate on walls and ceilings, cheers

Thank You Neil

[Soundman2020]

i was wondering your thoughts of lining the internal walls and ceiling of the tin shed with 60mm polystyrene foam, i understand it will do nothing for sound isolation and im sure the structure will handle that at least as its very light and i think it would be a good thermal insulation material against the hot and cold weather ???

As purely thermal insulation, it will work just fine. No problem.

Chipboard 2400mmx1200mmx18mm how can i work out what specific type of chipboard it is,

MDF weighs about 800 kg/m3, and according to a quick BOTE calculation, yours comes in at about 750 kg/m3, so you are in the ball park with that.

10mm gyprock? this may seem like a dumb question but 2 layers of 10 mm gyprock totalling 20mm thickness not better than 1 layer of 16mm gyprock ?

Not really. The problem is that, even though you have more TOTAL mass, it is now made up of thin, flexible layers, instead of being just one thick, more rigid layer. Even though the mass is there, each layer still acts on its own, to a certain extent, and 10, is very thin, very flexible, and has undesirable resonant characteristics. The ideal isolation materials would be infinitely thin, infinitely massive, infinitely dense, infinitely rigid, and also infinitely damped, ... which is impossible of course.... Unfortunately! So your best bet is to use the most massive, thick, rigid material you can find within your price range. For most places, that turns out to be plain old fire-rated 16mm drywall.

insulation batts 3 options
1. R1.5 Knauf Earthwool Insulation. 580mm x 1160mm x 75mm thick
2. R2.5 HD (High Density) Knauf Earthwool Insulation 580mm x 1160mm x 90mm thick
3. R4.0 Knauf Earthwool Insulation 580mm x 1160mm x 195mm thick
they are all low irritant fibreglass batts which one would be best, if not can you recomend which type of insulation i should use

What matters most is a characteristic called "gas flow resistivity". That's what determines how well insulation performs, acoustically. But most manufacturers don't even bother measuring that, let alone publishing it, since it doesn't mean much for the primary purpose of the insulation: thermal. Fortunately, it turns out that there is a rough, proximate correlation between gas flow resistivity and the density of each type of insulation: For fiberglass, the optimum density is around 30 kg/m3. For mineral wool, it is around 50 kg/m3. So whichever one of the above is closer to 30 kg/m3 is what you want.

you mentioned isolation goals? im really looking at building a room that i could play a drumkit in and maybe a guitar amp at the same time, approx 100 decibels max,

Drums come in at around 110 to 115 dB mostly. or louder. Add in a guitar amp, and you are approaching 118-120 dB (C, Slow). That's a realistic figure.

im assuming i dont go over that regurlarly as i would be going deaf,

Please don't take this the wrong way, but if you play drums, then you already are and just haven't noticed it yet. Medical studies show that a level of 115 dB for anything longer than about 15 minutes causes irreversible hearing damage, which is accumulative on each successive occasion. If you check the web sites for places like OSHA, you'll find more information on just how bad loud noises are, especially in the case when they are percussive. It's an eye-opener. Must of us sound engineers and musicians who have been exposed to loud sounds frequently for a few years, do have hearing loss: we jut don't know about it, until we go see the doc and he does a proper test. Ever notice how musicians tend to talk a bit louder than "normal" people?

but would like to isolate sound as much as possible within a tin shed,

OK, so assuming that you have levels of around 115 to 120 inside, how quite do you want to get that outside? (in terms of decibels).

Question regarding ,a true three-leaf system, you would have to have a "middle" ceiling suspended between the inner ceiling and outer one (the roof) by some type of isolation mounts.please explain ceiling suspended? some type of isolation mounts?

You could do it on isolation mounts, such as resilient channel, for example, but you could also just attach it firmly to the outer leaf. It would not be quite as effective like that, but still pretty good. As long as the final inner-leaf is fully decoupled, very well sealed, and massive, then you should be OK.

concrete floor is flat and healthy, floating floor gone, i will concentrate on walls and ceilings, cheers

Great!


- Stuart -

[neilstar]

Hello Soundman, i been doing what i can between working my normal job and playing in bands, i have another few questions before i go any further, any help and advice would be much appreciated, as per the pictures attached

i have lined the tin shed, cut pieces of polysterene foam to fit between all timbers, walls and ceilings, polysterene foam purely for thermal reasons, i spoke to a builder, construction friend who dropped in and had a look at what i wanted to do regarding adding mass to the internal walls of the original steel, timber frame work, he said the timbers were strong enough to screw sheets of the 18mm chipboard straight to the timber wall rails and the timber roof purlins, i have screwed 2 layers of the 18mm chipboard directly as mentioned, using plenty of flexible caulk on all joins, so now i have the external wall mass i think?? which is the 36mm of chipboard and the polysterene foam and the tin,

Question , do you think i should add something else to that outside leaf before building my inner wall,

internal room construction,
builder has convinced me to use a strong lvl bean as to his dimensions regarding the weight of mass i want top put on the inside walls and ceilings, 360x63x4800 long which is going sit on 90mmx5mm square steel posts either end screw bolted to the ground, and the lvl beam sitting on top and bolted to the tags which i have welded on, then im building the internal wall frame 90x45mm 600mm centres screw bolted to the floor all the way around room, then using 190x45mm rafters 600mm centres from wall frames up to the lvl beam, which i will eventually fill with insulation of the correct weight and screw 2 layers of plywood to all walls and ceilings, 1st layer is 22mm , 2nd layer is 16mm , then maybe add layers of 16mm fyrcheck on top? i hope this makes sense so far?

next is i bought a decibel meter and we definetly are playing at 120db(C slow) , that was 2 guitars, bass player, drummer, vocal PA, so yes u were right we are louder than i assumed and yes im probably going deaf already,

so my question is what is the best gap to use between the existing lined shed wall which is approximately 110mm thick that i have already constructed as above and the internal wall that i am about to construct, i was thinking of leaving a 300mm gap all the way round walls and ceiling, is increasing the gap to say 400 or 500 mm better for isolation results or is it just wasting space?

i also have some questions regarding split system air con, electrical cables, power point cables etc, and air in and out vents using fans and box constructions such as the picture included

once again, Soundman i appreciate yr time, effort and any advice you give

Thank You Neil

[tribal]

Hey Neil - I've just started an aussie steel shed makeover myself, really like how yours is coming along. I'm stuck with steel channel on the walls and ceiling which I don't think would hold the weight you've just hung. Just wondering if you used any kind of vapour barrier, or did the polystyrene have a layer of foil on it?

Looking forward to more pics.

[Soundman2020]

so now i have the external wall mass i think?? which is the 36mm of chipboard and the polysterene foam and the tin,

Question , do you think i should add something else to that outside leaf before building my inner wall,

Looks good to me. If it is "flaky" chipboard (LDF, not MDF)I would suggest maybe sealing it with any type of wood primer, but if it is proper MDF or OSB then that's not necessary.

builder has convinced me to use a strong lvl bean as to his dimensions regarding the weight of mass i want top put on the inside walls and ceilings, 360x63x4800 long which is going sit on 90mmx5mm square steel posts either end screw bolted to the ground, and the lvl beam sitting on top and bolted to the tag

That sounds like a good plan. Did you get a structural engineer to confirm that that's the correct type of beam and the right dimensions for the amount of weight you plan to put on it? The builder might be well-meaning, but only a qualified structural engineer can tell you for sure if it is safe and meets code.

i hope this makes sense so far?

sounds good on paper (or rather "on screen"), but I'd still run it by a qualified engineer to make sure that the structure can handle all that.

next is i bought a decibel meter and we definetly are playing at 120db(C slow) , that was 2 guitars, bass player, drummer, vocal PA, so yes u were right we are louder than i assumed and yes im probably going deaf already,

Yup. That happens with most musicians, so don't feel bad! Most of us do not realize just how loud things are (because it SOUNDS SO GOOD!) and also don't realize how easy it is to damage our ears...

so my question is what is the best gap to use between the existing lined shed wall which is approximately 110mm thick that i have already constructed as above and the internal wall that i am about to construct, i was thinking of leaving a 300mm gap all the way round walls and ceiling, is increasing the gap to say 400 or 500 mm better for isolation results or is it just wasting space?

I don't have time to do the math right now, but I would say that 300 mm is more than enough. You would not get much improvement from going to 400 mm.

- Stuart -

[stevev]

hey Neil, looks like you're making great use of your available space. nice work

Just having a look at the steel trusses in your pic and wondering if the ceiling of the internal roof will be built flat underneath the bottem chord of the truss, or whether you're planning to have an internal ceiling with the same pitch as the chipboard ceiling? If it's the pitched option then it looks like you'll be building the internal ceiling around the trusses which will end up coupling the three leaves together to some degree.

Steve

[neilstar]

Hi Steve, i am building the internal ceiling the same pitch as the chipboard ceiling, i have placed an extra rafter approx 100mm each side of the steel truss and i am going to box it in, it will not touch the steel struss at all, yes it will probably look funny at the end, i will add some pix of what i have been doing so far,

any comments , thoughts are much appreciated

cheers Neil

[neilstar]

hi, heres a few pics of what ive done so far,

[neilstar]

Hi Tribal, it was a corrugated steel roof, i covered the corrugated iron with a layer of this thin cardboard backed foil insulation i had left over from another job, if you look closely at the picture you can see that ive cut it exact size and wedged it between timbers before installing polystyrene and didnt use any on the walls, polystyrene straight against steel sheets

cheers Neil

[Soundman2020]

it was a corrugated steel roof, i covered the corrugated iron with a layer of this thin cardboard backed foil insulation

Did you check local regulations and local contractors, to make sure that that material is both allowable and a good idea? Where I live, roof decks must be ventilated underneath. Insulation can be used lower down, after a suitable air gap to allow for proper ventilation of the roof deck, but the deck itself is supposed to be free, to prevent issues with condensation, overheating, etc.

You might find these interesting:

http://www.ehow.com/how_4616045_vent-metal-roofs.html
http://homeguides.sfgate.com/ventilate- ... 63952.html
http://www.buymetalroofing.com/metal_ro ... lation.htm

What you did might be OK. Or it might not. It would be a good idea to check that with an expert who knows the local code and conditions.


- Stuart -

[neilstar]

Hi Soundman,

when i first was thinking of lining shed i was gonna leave a gap and install the polystyrene against the timbers, which would leave a 70 mm gap between steel roof and steel sheets, but a builder, contractor who was here having a look at what i was doing, suggested i do it this way, and be able to screw chipboard sheets directly to the timbers that are already there,

cheers Neil

[neilstar]

hello, i have read this comment on many different posts,

"""Proper HVAC is generally the most forgotten part of studio building, as people simply do not appreciate the importance. It is a major part of the studio: without it, you don't have a usable studio. It's that simple. You need a proper ventilation system, with fans, ducts and silencer boxes, correctly dimensions to move the right amount of air through the room, a the right speed, and you need an air conditioner to cool and dehumidify the air correctly: These are not luxuries in s studio: they are basic necessities, just as much as electricity and furniture"""".

question regarding,

i am installing a panasonic reverse cycle inverter 2.6kw cool, 3.6kw heat mini split system and also a ventilation system including fresh air in, fan, duct , silencer box,
and air out sliencer box duct and fan with speed controls on both fans,

Q. is it ok to have both inlet and outlet points for ventilation on the ceiling opposite sides of the room?, or should i really be having inlet low on a side wall somewhere?

Q.i have seen a couple of different D.I.Y designs of the silencer boxes which im willing to make, 2, 3 or 4 baffles,
but before i do i think i need to understand the basic principle, please explain and add any information, pics that would help, i have also read this many times,

""Three or four turns inside the box is about right, unless you have extreme isolation needs. The biggest issue is to ensure that you keep the cross sectional area inside the box as constant as possible, and at least twice that of the duct itself"""

Q. can you please explain how to work out the cross sectional area inside the box as constant as possible, and at least twice that the size of the duct itself?

the boxes im going to make fit in between the ceilings, i have an approx 300mm space between ceilings, so i was thinking of a box up to a size of
250mm high x 1000mm long x 500mm wide box, using 100mm duct, Q. is it best to use insulated duct or doesnt matter?

thank you again for your help Neil