New design

Plans and things, layout, style, where do I put my near-fields etc.

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1970428scj
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Joined: Sat Feb 29, 2020 2:44 am
Location: california

Re: New design

Post by 1970428scj »

Hi everyone, I have been working hard on the project but coming to some road blocks, I am stumped on how to do the 2 leaf system on the roof/ceiling.
Its a pitched roof with 2x4 trusses every 24", There are vents in the roof, what is my best way to tackle this?
Its a concerte tile roof, sheeted with 5/8" plywood. I did speak to a structural engineer about weight etc, he said the I could hang up to 4 sheets of 5/8 drywall with no issue, 10# live load and 20# for the top. the 2x4 trusses are 10'2" from the floor so height is an issue, I can wrap the lowest truss bringing the height up, or I can hang a ceiling with a mason product, The issue is the outer leaf, what to do?
Paulus87
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Re: New design

Post by Paulus87 »

Hi,

I gave you the answer in a previous reply to your thread but perhaps it wasn't clear so here's more info to clarify...

Here's a diagram I've drawn of how to maintain isolation and roof ventilation. You effectively build a two leaf assembly with a roof above. Since the roof deck is ventilated it is not really a third leaf, it is just a rain screen to protect your air tight double leaf assembly.

Note: If you do not have a height restriction (or are happy to not maximise your ceiling height) then there is no need for battens on the rafters/trusses. You can simply attach the mass layers to the bottom of the outer leaf rafters/bottom chord of the trusses, which saves you a lot of time since you no longer need to cut in the drywall between the rafters etc. If you are not planning on doing a cathedral ceiling then the outer leaf mass layers would go on the bottom of the ceiling joists, leaving the ventilated attic space above.

In your case, your inner leaf ceiling height is going to be defined by the bottom chord of your outer leaf trusses. Therefore you need as much space as you can get for your MAM cavity without significantly decreasing the height at which you can build your inner leaf ceiling. So the method demonstrated in my diagram may be a suitable way to achieve this.

The two alternative to this is convert your roof to a hot roof and block up the ventilation. This is where you would install rigid insulation (usually 120-150mm thick) above the roof deck and so your roof deck no longer needs to be ventilated since it is "inside" the structure. You would then apply your roof on top of the rigid insulation.


Paul
Paul
1970428scj
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Location: california

Re: New design

Post by 1970428scj »

Hi thanks for reply, my issue is I have a concrete tile roof on the building now, it would eat every bit of my money to remove this roof, I need a way to make the inner leaf no less than 10 feet tall, The drawing make sense but would put my ceiling height way to low.
Paulus87
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Re: New design

Post by Paulus87 »

You wouldn’t need to remove the roof if you stick with a cold roof design.

What is the height of the lower chord of the trusses?

Paul
Paul
1970428scj
Posts: 44
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Location: california

Re: New design

Post by 1970428scj »

Paulus87 wrote:You wouldn’t need to remove the roof if you stick with a cold roof design.

What is the height of the lower chord of the trusses?

Paul
10 feet this is the issue
Paulus87
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Re: New design

Post by Paulus87 »

1970428scj wrote:
Paulus87 wrote:You wouldn’t need to remove the roof if you stick with a cold roof design.

What is the height of the lower chord of the trusses?

Paul
10 feet this is the issue
If you want to maintain a 10’ inner ceiling height then you’ll either have to modify your trusses so that they can safely be made higher such as raised tie trusses or scissor trusses or you’ll have to compromise your isolation and either hang the ceiling like you suggested using resilient channel or just making do with a coupled ceiling assembly. The advantage to the last option is you could have an open beam style (or in your case open truss style) ceiling and have even more height with even more acoustic treatment.

How much isolation do you actually need?

Also, why not just settle for 9’? That’s still a very good height, 8’ is the one to avoid.

Paul
Paul
1970428scj
Posts: 44
Joined: Sat Feb 29, 2020 2:44 am
Location: california

Re: New design

Post by 1970428scj »

Paulus87 wrote:
1970428scj wrote:
Paulus87 wrote:You wouldn’t need to remove the roof if you stick with a cold roof design.

What is the height of the lower chord of the trusses?

Paul
10 feet this is the issue
If you want to maintain a 10’ inner ceiling height then you’ll either have to modify your trusses so that they can safely be made hugger such as raised tie trusses or scissor trusses or you’ll have to compromise your isolation and either hang the ceiling like you suggested using resilient channel or just making do with a coupled ceiling assembly. The advantage to the last option is you could have an open beam style (or in your case open truss style) ceiling and have even more height with even more acoustic treatment.


How much isolation do you actually need?

Paul
Paul thanks for the reply, i am not right next door to neighbors, but it gets pretty silent outside after sun down. I am trying to work with what I have but still looking for as much isolation as I can get , keep in mind my floor is a slab on grade, and I plan to leave it this way,

With a concrete tile roof there is mass there, I am at the top of the hill also which helps for audio.
Not sure how far to take this, if I have complaints from neighbors it’s a huge waste of money, so I’m looking to do as much as I can for the budget I have and building I have to work with.
Paulus87
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Re: New design

Post by Paulus87 »

I have a few ideas for you to consider...

but first I would get a sound level meter, then ask your nearest neighbours if it would be okay for you to do some tests in the evening sometime, then get some friends over to come jam with drums bass and guitar and ask them to play as loud as they can. Go to the boundary of your nearest neighbour and if they are friendly go inside their house and first see if you can hear it. If not, that's good. If you can hear it then take a measurement (everything else would need to be quiet in the room) see what it measures and then phone your friend to play some bass heavy music through your monitors at about 80-100db and see if you can hear it, measure etc...

Then do the same tests outside at the boundary of your neighbour, write everything down so you don't forget.

If it turns out that you're already getting a fair amount of isolation then that makes your job easier. If you can't hear it at all, then you do not have a problem and you do not need any isolation. Anything you do add to seal up the rooms will be a bonus and you can still have adequate isolation between the live room and control room. This means you can save a whole load of money and concentrate purely on acoustic treatment, which will be easier since you won't have rigid massive boundaries reflecting a load of mud back into your space.

It may turn out that when you do your tests it was only a problem with the band jamming but the monitoring levels were acceptable, if so then you really only need to isolate your live room but do not need to fully isolate your control room. In this case you could settle for a lower ceiling in the live room with a fully decoupled double leaf assembly, but your control can just be as it is now or you could build it as you would a normal residential room - single frame with mass either side and then put your ceiling drywall up in between the trusses leaving a 2" air gap for your continuous ventilation path above the drywall. (basically like my drawing but without the inner leaf). This would allow you to have as high a ceiling as you'd like in your control room with lots and lots of room for bass trapping up there, which would really be a massive benefit to the acoustical response of your mixing environment. I'd rather have a larger control room than tracking room, especially when it comes to ceiling height. Yes, of course it's nice to have a huge tracking room with high ceilings, but it is not as important as the acoustics of your control room.

If it turns out that you need to isolate both rooms, then by how much? Perhaps your MAM cavity can be reduced significantly if your isolation needs are not absolute. A suspended ceiling may work fine in this case.
The problem with relying on your vented roof as your outer leaf is that it is unpredictable, despite it being built from concrete tiles (excellent for isolation) it would be very difficult to calculate exactly how much loss you will get through the vented parts, and a double leaf system is only as strong as its weakest link. It would be like trying to keep water in a fish tank that has lots of little holes or cracks... the water would probably leak out faster than you can refill it.

Therefore there is no point spending a load of time and money and effort making your walls massive with a huge amount of isolation if your roof is full of holes.

Paul
Last edited by Paulus87 on Wed May 13, 2020 8:19 pm, edited 1 time in total.
Paul
Paulus87
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Re: New design

Post by Paulus87 »

Is there any reason why you can't simply do it like these diagrams?

For the outer leaf, fix some 2" battens to the inner side of your top chords, cut the drywall and fix it in each of the bays onto the battens. The 2" batten will mean there is a continuous air gap for your roof ventilation and will give you something to fix the drywall to.

For your inner leaf you have 3 options, you can frame it below your bottom chords and then drywall the underside of the inner leaf joists, this will drop your ceiling down to about 9.5' or something. (See diagram)

Or frame the joists so that they go in between the bottom chords of your trusses and then fix the drywall on the bottom of your inner leaf joists, thus maintaining your 10' height. (Like the diagram but the joists would be higher up, in between the bottom truss chords)

Or you can frame it so that the joists run below the bottom chords of the trusses and then you do what we call an inside out ceiling - basically you would build frames that fit in between your inner ceiling joists with the drywall on the top side of the frames, then lift the frames (or modules) into position between the joists and fix. This will enable you to maintain your desired height and gives you a nice lot of framing depth into which you can put your ceiling acoustic treatment. (See diagram)

All of those methods will enable you to have total isolation and a good ceiling height. It's a lot more cutting and fussing, but you'll be able to have your cake and eat it.

Paul
Paul
1970428scj
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Re: New design

Post by 1970428scj »

Hi thank you for your time on this, all great ideas,but with all the labor, cutting, sealing etc , it seems I will be saving very little money to only get 10' ceilings, I am speaking with a engineer now and may just bit the bullet and raise the damn roof,
In all my calculations 11' ceilings was the magic number for roof ratio.
I will at least explore the option of raising this thing up. If all else fails your ideas will be what I do,
Im 48 years old and this will be the last studio I build so I want those damn high ceilings!!

On a side note , where can one buy mason products? I am in Southern California and have tired calling Mason West a few times with no luck.
Thank You
Paulus87
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Re: New design

Post by Paulus87 »

1970428scj wrote:Hi thank you for your time on this, all great ideas,but with all the labor, cutting, sealing etc , it seems I will be saving very little money to only get 10' ceilings, I am speaking with a engineer now and may just bit the bullet and raise the damn roof,
In all my calculations 11' ceilings was the magic number for roof ratio.
I will at least explore the option of raising this thing up. If all else fails your ideas will be what I do,
Im 48 years old and this will be the last studio I build so I want those damn high ceilings!!

On a side note , where can one buy mason products? I am in Southern California and have tired calling Mason West a few times with no luck.
Thank You
If getting 11' ceiling height is a huge priority for you then that will be the simplest way to do it. However, I still think you should carry out the isolation tests that I suggested, if you do not need the amount of isolation that you are proposing then it would mean you could have even higher ceilings since you'd have access to the full height of your trusses. If you do not like the look of open trusses then you can cover them with a fabric drop ceiling - your acoustic height and volume would not be changed, only the visual appearance. This would give you a huge amount of space for bass trapping - which is even more important in the ceiling, it's perhaps the most important place of all to have huge amounts of bass trapping since it is usually the smallest dimension.

With all that said, if you do decide you need to raise the trusses you should calculate first what your MSM assembly depth needs to be in order to achieve the level of isolation you require. So, use Gregwor's MSM calculator to help you work that out and then add up the total depth of the mass layers, framing and cavity depth. Whatever that measurement is will be the minimum amount of space require for your 11' ceiling and then you'll be able to work out how far up your trusses need to go to achieve this. Don't forget, you'll need a a lot of acoustic treatment on your ceiling as well (2' or more would not be over kill) even though treatment does not change the actual acoustic height of the space you still want to make sure the visible ceiling height will be where you want it. Then take the new height that your trusses need to be to a structural engineer and see if it's physically possible.

Paul
Paul
Paulus87
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Re: New design

Post by Paulus87 »

And I do not know where you can buy Mason Industries products, I am in the UK so won't be much help, sorry about that!

Paul
Paul
1970428scj
Posts: 44
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Location: california

Re: New design

Post by 1970428scj »

Paulus87 wrote:And I do not know where you can buy Mason Industries products, I am in the UK so won't be much help, sorry about that!

Paul
Paul, cheers
Thank you much for the info, A friend of mine that is a structural engineer is coming over this week and we are going to look at our options, I will post what he says.

My next thing will be A/C and fresh air in to the studio.
Do you have any info on what is best, mini splits or central A/C.
I have search and ready some what on this forum, Rods book etc .

My project will go dark for 2 weeks at the end of May and I will need to get my designs and plan more together, ready to make moves mid June.
1970428scj
Posts: 44
Joined: Sat Feb 29, 2020 2:44 am
Location: california

Re: New design

Post by 1970428scj »

Wanted to share a few ideas
1970428scj
Posts: 44
Joined: Sat Feb 29, 2020 2:44 am
Location: california

Re: New design

Post by 1970428scj »

I guess I can only attach a few images.
The above 2 are the rear entrance to the live room, fence for trash cans,
Others are the front, I am pouring/extending a concrete sidewalk to the front entrance.I have added sewer, water and drainage lines for RV hook ups.
There will be a concrete patio poured with the remaining concrete from the truck, there are deep footings in the edge for future expansion .
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