shabbey road construction advice please

[shabby road]

Hello folks
I need some advice with soundproofing the interior of shabbey road studios a 3.4 meter long x 2.3 meter wide x 2.7 meter high detached, cement floored, windowless, 18 mm timber roofed, 100mm concrete block walled, garden studio. (See photo "outer shell")

bare shell.jpg

I understand very little about studio design/soundproofing but i compose library music for a living (primarily music used on adverts and radio) everything is created on a computer. I will require to play guitar through a guitar amp but I will not require soundproofing for a live drum kit as I don’t use one.
The garden studio structure is situated right next to the windowless wall of our neighbour’s end of terrace house. We live in a busy residential area I want make it as quiet as possible as I do much of my work between 7pm to late at night.

After researching the internal construction from various sources (especially this forum) I have arrived at these solutions-

For the doors....
2 x fire door entry system with 25mm air lock

For the walls...
Outer concrete wall 100mm thick
Air gap 25mm
Stud partition 50mm thick (filled with mineral wool)
Resilient bar
2 x layers of different thickness plasterboard sandwiched with green glue

For the ceiling....
New joists attached to top frame of wall studs (filled with mineral wool)
Resilient bar (hat channel type)
2 x layers of different thickness plasterboard sandwiched with green glue

Please let me know if you agree with the wall ceiling construction overview?

roof cieling and wall construction.jpg

My main question is about the existing roof as this seems like the weak point for sound escaping....
The existing roof of the outer structure is 18 mm chipboard with a professionally laid bitumen/felt top. Under this are 150 mm joists with furrings on top of the joists to create a slope for the roof run off. The joists sit on a timber bar which sits on top of the last row of concrete blocks (see photo "joists" plus "roof underside exterior" and drawing "existing roof")
Before building the new independent ceiling attached to the stud walls would it make sense to cover the underside of the chipboard roof with one or two layers of plasterboard followed by a layer of mineral wool?

joists.jpg

roof underside exterior.jpg

[/b] (See drawing "existing roof"

existing roof insulation.jpg

My budget for the soundproofing to include fan assisted natural air intake and outake system and baffles is around £2000 i would like to do the work myself.

I also understand i need to arrange the inner walls non square to avoid standing waves but wanted to go one step at a time with the questions.

Thanks in anticipation

Tim

[Cold]

Hi Tim,
Are those internal or external dimensions?

Have you tested as is?

The reason I ask is because that is going to be extemely tight once you put in isolation and treatment.
I would see if I could get away with the existing structure with a better door and a ceiling. Then use a guitar amp isolation cabinet.

Creating a roof system that lets the roof breathe and gives you at least equal isolation to your walls, plus building a super door may be enough if you don't monitor too loud.

Biggest problem I see ( besides limited space) is how to insulate this properly.

Can you do a drawing showing the internal dimensions?

If you do room in room the res bar becomes redundant.

Steve

[shabby road]

Thanks Steve very much for your reply it has already helped me a lot here are the answers to your questions.

Are those internal or external dimensions?

Unfortunately they are the external dimensions see plan below for internal dimensions the room is not square by the way

internal dims web.jpg

Have you tested as is?

Yes but only very simply I played my iPod dock inside at moderate volume with the door closed and stood outside to listen. The difference between inside volume and outside volume is negligible. I am sure that this is down to the open air cavity’s created where the roof joist sit on the walls (see drawing and photo below)

roof insulation cross section web.jpg

roof underside exterior.jpg

The reason I ask is because that is going to be extremely tight once you put in isolation and treatment.
I would see if I could get away with the existing structure with a better door and a ceiling. Then use a guitar amp isolation cabinet.

That sounds good! Would you suggest adding additional mass to my roof underside (see drawing above roof insulation cross section) then attaching a new stud ceiling on a res channel?
Also I like the idea of one super door rather than 2 doors. i have seen some stuff on here about creating super doors could I use my existing fire door as a start it weighs a ton?

Creating a roof system that lets the roof breathe and gives you at least equal isolation to your walls, plus building a super door may be enough if you don't monitor too loud.

Re breathing - I was aiming to build an air baffle outside the structure or enclosing it in one of the larger joist voids. Don’t want air conditioning so would I still need two separate ins and outs or would a simple open vent inside and a vent outside with a baffle/silencer do it?

Biggest problem I see (besides limited space) is how to insulate this properly.

I know it’s a tight space (all planning regs would allow around here) but provided I can get my 140 mm x 70 mm workstation in there myself, a small amp and a few instruments with soundproofing i will be very happy


If you do room in room the res bar becomes redundant.

That help a lot due to limited space how about insulated stud walls attached to existing concrete walls then res bar and 2 x plasterboard?

i am open to any suggestions about how to best achieve an adequate level of soundproofing for my needs/ budget. I know this is a puzzler due to the "nano studio" aspect of the build

Thankyou

Tim

[Cold]

Hi Tim,

I don't have a bunch of time right now so I'm strictly going to give you a few things to research.
I think you meant cm in your drawings
I don't know if you can get away with a sealed roof system in London. Do some research on hot roof systems and see if its allowed. Otherwise no point in adding mass to your roof if it has to be left open for ventilation so it doesn't rot.

Same thing with the walls. You have to be careful with a concrete shell as to how you insulate it to avoid trapping moisture. Normally you have to separate the studs from the shell. Check with your local builders And code people.

With the size of the build, I would try to use some kind of inside out wall system, but also getting proper condensation control is going to be tough. Because with your inside dimensions, pretty well the whole inside of the building will have to be treated to make it a usable space. So if you built a 125mm isolation wall, plus another 100 mm all the way round for treatment, plus even thicker in the corners for bass treatment.... That's why inside out walls would be good , if workable.

2 vents, 1 in, 1 out.

You live in a similar climate to me, condensation always must be factored in.
I would use spray foam, not sure about your codes.
Steve

[Soundman2020]

Hi Tim, and welcome to the forum!

A couple of quick comments and questions:

1) What is the purpose of this room? Is it going to be a rehearsal space, or a control room? Two very different scenarios.

2) How much isolation do you need, in terms of decibels? That is the key to everything. Before you even think about structures, masses, seals and suchlike you must determine the level of isolation you need for your room, using a sound level meter. With that number in hand, then you can look at the types of construction that are know to produce that level of isolation, and choose one that fits your budget. That, in turn, will determine your building materials, techniques, masses, air gaps, etc. Without knowing the basic number, it is all just guesswork, and "guessing" is not a good way of building a studio!

3) ...

Don’t want air conditioning

Sorry, but you don't have a choice. "Soundproofing" that room (more correctly called "isolating") means that you HAVE to seal it completely airtight. There can be no air paths at all. sound is just air molecules vibrating, so if air can get in and out, then so can sound. Even a tiny gap is unacceptable. Your body puts out heat and humidity, your equipment puts out heat, and your mics and musical instruments are sensitive to changes in both heat and humidity. A small room like that is going to get awfully hot and stuffy in a very short time!

So it is not an option. So you NEED an air conditioning system, regardless of whether or not you WANT one. And that system needs to be dimensioned to take care of your heat and humidity, as well as taking into account the issue that you need to get fresh air into the room (so you can stay alive) as well as exhausting stale air from the room, without compromising the isolation.

HVAC is very, very often overlooked in early designs for home studios, but it is an absolute necessity. Some people think they can just leave the door open: nope. If the door is open, then why bother to soundproof the room at all? Besides, a single open door into a sealed space will not cause air to move in and out.... so it would not work anyway...

so would I still need two separate ins and outs or would a simple open vent inside and a vent outside with a baffle/silencer do it?

You need one inlet, with fan and silencer box, plus one outlet with fan and silencer box, plus the actual air conditioner unit itself to take care of the heat and humidity. For that sized room, a small mini-split system is all you need.

That help a lot due to limited space how about insulated stud walls attached to existing concrete walls then res bar and 2 x plasterboard?

If you attache the studs to the concrete then you DO need the resilient channel, or RSIC clips plus hat channel. It is only if the studs are NOT attached to the walls or ceiling that you can forget about them. The reason is this: your inner leaf must be decoupled from the outer leaf (concrete block wall). You can decouple it either by using the RC (Resilient Channel) or by leaving a gap between the new framing and the concrete, but you do not need to do both. Either way will decouple just fine, and decoupling twice is a waste of time, space and money.

i am open to any suggestions about how to best achieve an adequate level of soundproofing for my needs/ budget.

Define "adequate level"! That's the number you need to come up with: the number of decibels of isolation that you need.


- Stuart -

[shabby road]

Hi stuart and steve thanks very much for your replies its all helping...

What is the purpose of this room? Is it going to be a rehearsal space, or a control room?

The room is going to be a control room for writing and mixing my own music up to now i have been doing this in the front room of our flat.
i have pretty good control over the overall volume level as the main recording is software based with no live drums. The only noisey aspect is recording an electric guitar but the live volume of the gtr amp is currently controlled and recorded via a speaker simulator and powerbrake so its not that loud. Acoustic guitar and vocals are individually tracked so it shouldnt get any louder than that.

How much isolation do you need, in terms of decibels

seems like the first thing i need to do is determine the level of isolation i require in decibels not entirely sure how i do that? standing in front of my speakers at my typical monitoring level with a sound meter? please can you let me know about how to attain the DB reading to enable the approach for the isolation

you NEED an air conditioning system, regardless of whether or not you WANT one

i was hoping to avoid it and get by with an in and out fan airflow so i can breathe but i guess i will have to also factor in an AC unit from what you are saying.

Thanks

Tim

[xSpace]

"That help a lot due to limited space how about insulated stud walls attached to existing concrete walls then res bar and 2 x plasterboard?"

What you are in want to do is create an exterior mass wall/and an air space/and an interior mass wall. This is the simplified version of a mass/air/mass assembly.


What you are suggesting is as wrong as your first version, if not worse.


"Before building the new independent ceiling attached to the stud walls would it make sense to cover the underside of the chipboard roof with one or two layers of plasterboard followed by a layer of mineral wool?

No sir. Use typical roof sheathing/decking for this. Some here will tell you that the air space is breached due to the soffit vents...whatever right?


"I understand very little about studio design/soundproofing"

This needs to be your guide. As long as it took you to learn your instrument you have to understand that this is not a hack event or something that can be read about and installed into your area...it is far more complicated than that.

In respect to insulating the rafters of the shed...maybe not so much. This is an area that is highly involved in the heat/cold transference of the structure.

At first glance it may seem an easy thing to just stuff insulation into the rafter cavities. But consider the elements and how they interact with this cavity.

The standard is to install urethane in the upper rafter area and that the goal is to bring this into the the thermal environment of the structure.

To simple install insulation negates the effect of the heat /cold transference that exists on a day/to/day basis in the structure due to the external environmental impact.

In a hot climate the potential for the roof to sweat is dominate. Anything you do that interferes with this interaction will produce an environment that holds condensation usually in the insulation added to the roof. This is rot.

So what if it is cold? Same thing, just might take longer depending on the geographical area you are in. The roofing gets cold, transfers this to the structure, then the insulation gets in the way.

Come the first bit of heat, the cold moisture trapped in the insulation un-thaws and creates moisture that is now trapped in the insulation. Same thing only different.

[shabby road]

Hi folks lots of different opinions feeling a bit overwhelmed please look at the picture below and let me know what you think as an approach for my walls. The picture is from a uk companys website called keepitquiet.com
Does anybody here know or rate them?

07_Resilient_R1 walls.jpg

a definitive approach for the new ceiling would be most helpful just spell it out as i am in circles a little please have a read back for more detail on that ceiling stuff.

I have looked into the sound levels I am aiming to achieve.The loudest noise i make is seems to be around 95db Looking to lower that to about 50 db with isolation?

Much appreciated

Tim

[Cold]

Hi Tim,
Did you look into whether or not you can use spray foam?

In Vancouver, we don't tend to put boards directly against brick walls, they like to rot.

You have to deal with three different but interconnected issues here.

1 how to insulate your building so it doesn't mold or rot.
2 how to sound proof your building to an acceptable level
3 how to treat the inside so that your soundproofed building is a usable .

#1. The best solution, if allowed, get the roof of your building sprayed with 2" (50mm) of 2lb foam. Spray all the way down till would meets concrete. This is a medium density foam that is also an air/ vapour barrier. This will let you seal your roof and make it worthwhile to add extra mass to the existing roof structure. You can get DIY kits, but they do not have the coverage advertised, and you have to completely understand the safety hazards. Cheaper in the long run to get a pro in to do it. Safer too.

Please check with builders regarding code for both the ceiling and walls. Bricks tend to wick moisture through them, so your going to have to do something about that. Sealing them might be an option, but then you trap moisture between two air barriers, not good. You could spray the walls with foam as well, but then you lose another 50 mm of space because you have to frame without touching the foam. If you frame first and the foam bridges the studs and bricks, you will lose the value of having two separate walls. You could also use rigid closed cell foam board on the walls in place of sprayed foam.
Talk to your local builders.

#2. This all depends on whether you seal the roof or not. If you don't seal up your roof, it may limit the value of building heavy walls. Remember soundman's fish tank analogy.

#3. Ok, you have it all soundproofed, now your going to lose another 100 mm all the way round minimum, just to make it sound half decent. Unless you can figure out how to incorporate inside out walls into the isolation framing. I say minimum because in a small room you're also going to need heavy bass trapping and that tends to eat up a bit of space. Make sure to look at John's studio in a box for some ideas.

So you have an isolation number in your head, next step is to talk to some local builders and check your local code for construction do's and don't's.
Make sure you look through the references posted here as well.

Steve

[shabby road]

Hi Steve

Thanks for that very clear advice I will look into all up the points you mentioned with a bulider i trust and trawl the other threads you pointed out.

One thing below is foxing me a bit as I can't find the reference for it?

#2. This all depends on whether you seal the roof or not. If you don't seal up your roof, it may limit the value of building heavy walls. Remember soundman's fish tank analogy.

Don't really understand why sealing the existing roof with spray foam vs. rock wool or mineral wool would stop the potiential problem of condensation/rot that the previous chap mentioned? Is it because the foam is non porous and becomes part of the roof?

In Vancouver, we don't tend to put boards directly against brick walls, they like to rot.

I am cladding the outer structure of the studio with timber battons follwed by treated ship lap timber ( i can't do anything deeper outside the structure due to my planning permission). According to a trusted builder this cladding should weatherproof the outside keeping moisture off the concrete blocks and stop moisture wicking through to the inside. I understand this would then enable me to fix studs to the inner wall without any damp issue.

Tim

[xSpace]

#2. This all depends on whether you seal the roof or not. If you don't seal up your roof, it may limit the value of building heavy walls. Remember soundman's fish tank analogy.

Don't really understand why sealing the existing roof with spray foam vs. rock wool or mineral wool would stop the potiential problem of condensation/rot that the previous chap mentioned? Is it because the foam is non porous and becomes part of the roof?

Tim

The fishtank analogy does not apply to the exterior of a structure. If anything it would create more issues than it would resolve.

Tim you should discuss this with a reputable builder/remodeler in your area. What Cold is suggesting is, in part, what I recommeded. The roof can be sprayed but if you do the entire walls and the roof all at the same time, this might not work to your advantage, since essentially what you are doing is creating a vapor barrier at the point of the insulation.

A vapor barrier that is now in the middle of the wall assembly and that is never a good thing.

As long as you do not completely remove the air path of the roof with your denim insulation, it will be OK.
Using something like this:
http://www.google.com/imgres?imgurl=htt ... CEYQ9QEwBg

Compromise is the first obstacle we meet on the road to recording nirvana.

[Cold]

It you are protecting the outside of the brick, ignore the comments regarding using foam on the walls.

Here is a link regarding sealed roofs:

http://www.buildingscience.com/document ... oof-design

Specifically page 6, figure 11

While Xspace is correct that 2 vapour barriers are bad, if the foam is thick enough, the dew point falls into the foam, making it a valid system. But, always make sure to use a tested and approved system.

The reason to go with a sealed roof is because it now can become a proper leaf of your system. It allows you to decouple your drywall ceiling and have 2 proper leaves within the smallest amount of space. If you keep your roof vented, it cannot work as a proper leaf, seriously limiting your isolation.

Remember where the sound escaped in your initial tests?

Steve

[xSpace]

"While Xspace is correct that 2 vapour barriers are bad,"

My comment had nothing to do with two vapor diffusion retarders (Vapor barrier) it was to help align where the vapor barrier is the most productive and that is not in the middle of a wall assembly.

The first line of defense is ALWAYS at the point of penetration.

Anything above ground elevation would at least be properly sealed, maybe even painted. Concrete block is a very porous material and can and will soak up moisture until the point of saturation and move right inside. Same thing with brick...it is like a sponge.

You cannot stop exterior moisture or water problems by approaching a level of attack from the interior side, it will not work, if the problem is related to cracks or poor exterior wall preparation, deteriorated wall sealing or the often as likely event that the ground elevation has gotten higher and is now covering the, what was, unprotected exterior wall. This is not uncommon especially after years of snow, water movement, owners modifying the grounds, flower beds being built up against the walls, etc., etc.

But let's entertain the notion that maybe all these barriers on the exterior are in place and are working properly. You still do not want to place insulation up against the concrete/blocks since the >potential< for the dew point to change with the climate still makes that path a two way street, it can come in and it (moisture/condensation) can go out.

So "warm side to the cold side" can change and does change. Now if we add insulation properly, to the newly framed wall assemblies as required by acoustic law, then you are going to make the interior side of the room the warm side...if not always, at least in large part. Then you add electronic gear, human bodies and you will be warm mostly all the time, and that leads you to HVAC.

The ability of a properly installed and sized unit will be able to even out the moisture in the room(s) so cannot be over-stressed.

This brings us to the VDR or vapor barrier. When you frame wall assemblies you install the VB on the interior side of the framed wall assembly. Not that it (the VB) would go anywhere else in a cold region but it could be a case that you would not need one, but that would be determined by the actual wall assemblies that exist, the materials they are made of, the perm rating of said materials, etc.

But, to be fair and in short, you have to address these issues from the exterior first because what you are going to do in the interior side is basically capture the ability of condensation to move, and take it out of the environment.

In cold regions, the VDR (your VB) goes on the interior side of the living or heated environment directly attached to the studs. This is not up for negotiation, it is based on the principles of moisture diffusion, while very complicated for those that continue to study and up-date the phenomenon, there are standard considerations.

Short answer is that in a climate with 8000 heating degree days (8000 / 72 degrees= 109 days of cold weather) the VDR is placed on the interior side of the room...no discussion.

At 4000 heating degree days and depending on the materials that the wall was built from a VDR might not, and mostly will not be used...this would be close to where I live in Grand Bay, Alabama.

As an aside, based on the perm rating of the materials I wouldn't think that my home that is only 27ish years old would have required one, a VDR that is. But it does have one, and it is on the interior side of the framing. We have about 3 or 4 weeks of cold weather, and this cold here isn't below freezing cold like you guys experience.

So why does it work? It works because the HVAC helps in the process. Had it not had one, nothing would have changed really. The ability of the wall assembly to dry from interior to exterior or from exterior to the interior would have been made possible by the number of heated days (by the Sun) or the HVAC.

So while they got it wrong, they still got it right.

Now if we were in a tropical environment, the placement of the VDR would be on the exterior of the framed assembly, often the VDR will come in the form of the actual finish, like say Stucco. But I guarantee you if you placed your VDR on the exterior side of the wall assembly in a cold region, it would not work, it would do what it is supposed to do, but the problem would be that the structure would suffer and rot, mold and decay would be the by product.

But to place the VDR in the middle of a double wall assembly is asking for trouble. I have to go back to my soft drink can analogy to perform this next magic trick.

Kid gets an aluminum can soft drink out of the refrigerator. Within seconds of being outside of the cold environment, the can starts to sweat. Now you think this sweat is part of the can don't you? It isn't, it is condensation in the air, the warm air to the cold side of the can. Now take that analogy and place it on the inside of the middle of a wall assembly full of insulation and what happens?

The gas that is condensation when moving from the warm side to the cold side will "hit" the solid plastic sheeting, and stick to it.

When the house starts trying to dry out, the moisture will migrate back into the interior framed wall, but before it makes it inside it has to go through the insulation on this interior wall.

And it cannot make it...it will diffuse on the insulation, wet the insulation and become a big problem and you will not know about it for months and months.

[Cold]

Brien,

If you get a minute or two can you take a look at this link?

http://www.buildingscience.com/document ... -guideline

In our climate all concrete or brick type walls are sprayed with 2lb closed cell foam, it has pretty much become the standard.

You have to think of it as your pop can with a foam can cozy.

Steve

While we are a bit off topic, it is important that this is discussed as the op's walls are brick.

[xSpace]

Brien,

If you get a minute or two can you take a look at this link?

http://www.buildingscience.com/document ... -guideline

In our climate all concrete or brick type walls are sprayed with 2lb closed cell foam, it has pretty much become the standard.

Two things Steve.

Specifically what paragraph/section would you like for me to look into.

Second. The use of the words "all concrete or brick walls" would need more support than an anecdotal statement from a member of this community.

Is that a fair statement?

I will read the entire document as always, but some clarification is required on your part if we are to come to a better understanding of both of out climates and the common practices used as it pertains to best practice.