New build, isolation req. Control room enviroment

[Purelythemusic]

Ok Quick update!

I have just 3 or 4 weeks max to find out if the building is approved by the local coucil...

The structural engineer isn’t happy with the thickness of the outer walls at that height for lateral stability so initially suggested a few piers to strengthen. Then he suggested that possibly as mortar joints may be the most likely weakness sound wise, maybe a cavity wall with ties built in and infilled with reinforced vibrated concrete would be a belt and braces sealed solid wall for the outer wall / leaf. The outer wall would then be 300mm thick solid concrete on a strip footing.

He is happy to support the 100mm block wall on a reinforced concrete slab not tied/connected to the outer wall/footing. The long walls would need a steel tie for lateral support though the new ceiling would also provide support.

He’s going to do the calculations when the council has approved the build.

I know this changes the mass of the outer wall and MAM test experience shows greater results when both walls are beefed up to be similarly massive but I don’t think it’s practical/necessary to go further with the inner wall as the raft slab is nice and simple as it is! I’m only going big with the outer wall as it’s easy and should be fairly easy to do.

[Purelythemusic]

Hooray!

I have approval for the building!

I just need to get the structural engineers calcs before getting started, plus the current project is going to run for another couple of months.

It would be useful to have some input in case I’m missing any issues with having such a massive outer wall... as mentioned in my previous post it’s planned to be 2 x 100mm concrete block walls with concrete as an infil to make one leaf. The inner 2nd leaf will just be 100mm concrete blocks. 150mm gap in between filled with rockwool but not physically tied. Inner room ceiling to be double or tripple boarded while the outer wall will have a block amd beam roof with screed on top finished with liquid waterproofing - we use Kemper. Again roof not connected to the ceiling at all. Going to try to separate the slab from the footing and external wall as well. Finished floor height will be around 500mm below ground tas we are restricted on finished building height.

Any further points to consider?

[Purelythemusic]

Hi All,

Getting close to starting this build, I just wanted to clarify that I am planning to use this room as a multipurpose space, recording drums and other live acoustic instruments as well as mixing down as in a control room setting. I know that for a live room you would want different acoustics to a control room so I am planning to aim for a control room environment which I can record in and add live ness digitally.

I don’t have enough space for 2 rooms so I am building one good one!

I’d appreciate any further feedback before we break ground.

[Soundman2020]

I have approval for the building!

Congrats! That's a milestone for sure!

as mentioned in my previous post it’s planned to be 2 x 100mm concrete block walls with concrete as an infil to make one leaf. The inner 2nd leaf will just be 100mm concrete blocks. 150mm gap in between filled with rockwool but not physically tied. Inner room ceiling to be double or tripple boarded while the outer wall will have a block amd beam roof with screed on top

That's a pretty heft construction, and should get you excellent isolation! What do your calculations show? How many dB of transmission loss will you get with that?

Also, what are your plans for doors and windows (if any)? With that type of huge mass in the walls, you are going to need some pretty major doors, hinges, closers and seals.

Any further points to consider?

HVAC? What flow rate / flow velocity / static pressure / sensible heat load / latent heat load / etc. are you planning for? And how will you build your silencer boxes for such extreme isolation? The silencers are going to be massive, I presume?

I know that for a live room you would want different acoustics to a control room so I am planning to aim for a control room environment which I can record in and add liveness digitally.

Well, you CAN add reverb in the mix, but it's often not as convincing as the real thing. Why not just treat your room with variable acoustics, so you can adjust for both scenarios? Design them so when one side is facing the room you get the correct acoustic response for a control room, but when you flip/slid/rotate each device so the other side is facing the room, you get a much brighter, more live, more reflective sound, with much longer decal times?

I’d appreciate any further feedback before we break ground.

How about posting your final design details here, so we can see what you have in mind?


- Stuart -

[Purelythemusic]

Hi,

Thanks again, yes I do need to plan my hvac system, I have, no clue about those systems so will be getting onto that shortly! I do only need 65db isolation, I am designing the floor, walls and roof to exceed that, but as long as the HVAC silencers are suitable for 65db then I should be ok.

A great idea to design panels which can be multi use, the standard low frequency issues would be permanent which is fine, as long as the room could be livened up for acoustic instruments and possibly some vocals.

I am thinking it may be worth employing a suitable designer to help polish up the important details now, rather than risk getting it wrong!

There is a company who has a workshop in Bristol that I have a contact in who may be able to supply cheaply some old studio doors. I do need to ensure they are up to spec.

I will run some calcs for theoretical TL of the wall system.

Attached are some of the latest design details...

In consultation with the Structural engineer we are going a step further with the inner room ceiling and going block and beam with concrete atop. Main reason is to help weigh the inner room including slab down in case of high flood water, he also said it would be beneficial to allow a gap between the slab concrete and the outer structure, which all ties in nicely with decoupling where possible. I have planned a 50mm space between slab and outer walls filled with 50mm rockwool as compressible material. I think there will be transmission through the slab through the grade in contact with the strip footing of the outside wall but it is about 1 metre below ground so do we think this may cause a problem aiming for 65db isolation?

With the inner room ceiling now being block and beam with concrete, the room and slab has been lowered a further 200mm into the ground in order to clear the steel holding up the outer walls' block and beam roof. The steel will be 254x146 I beam section, details soon. There is planned 80mm clear gap between inner room ceiling and steel, a clear 300mm between block and beam ceiling and roof.

Building this will be a bit tricky, but I plan to excavate to 1.4m for the strip footing and excavate the oversite (where the floor slab will go) at the same time, pour the strip footing and build the outer wall up above existing outside floor height then deal with the slab preparation.

[Purelythemusic]

As we approach the final basic design completion and get into starting construction it occurred to me that I hadn’t considered how the building will cope with water vapour... obviously unTil now I knew that an HVAC system would be needed to bring in fresh air and remove stale air, possibly provide climate control as well but here in England, we design buildings taking into account of interstitial condensation.

For those who don’t know interstitial condensation occurs within the fabric of a building when the water vapour carried through by warm air condenses when it reaches a part of the building that is at a temperature close to or below the dew point.

In normal cavity design there is a cavity tray provided which spans the cavity angling water that has got in there to the outer leaf where it can escape through small holes called weep vents. This would severely compromise the sound isolation so is not an option.

Another construction method which is not at all common for some reason is the method we used on our extension - solid wall with External Wall Insulation. The dew point is usually in the last 25mm of insulation so any that occurs is way outside the building and evaporates through the breathable render system.

I think this is the only feasible option for the studio. The thinnest recommended EPS (Extruded Polystyrene) is around 70mm to be sure the dew point is outside.

My 2 concerns are:

If I have insulation in the cavity as a dampener in my mSpringM wall system is there a chance the outer 300mm thick concrete wall won’t actually get warm at all or take ages...not sure if this is a valid concern...

The render coating is around 8mm in total (thin coat DPR Acrylic render by Parex) I assume this won’t have any detrimental effect on the MSM system by acting as a third leaf? The outer leaf is so massive I’m hoping there won’t really be much energy to resonate within the EPS!!!

Thanks for any thoughts.

[Soundman2020]

If I have insulation in the cavity as a dampener in my mSpringM wall system is there a chance the outer 300mm thick concrete wall won’t actually get warm at all or take ages...not sure if this is a valid concern...

The thermal characteristics of walls and insulation are not really my area of expertise, so I'd suggest that you consult an expert on that to get the real answer.... but it seems to me that the thermal mass of a 30cm thick concrete wall is pretty high to start with: It isn't going to heat up or cool down at high speed anyway, so I would expect that the insulation doesn't have too much influence here. The warming is going to come from both sunlight on the outside, and also from heat transfer in the cavity. How that actually works in practice is something that I'm not aware of.

What I do know is that when you build a wall correctly, and apply the correct "barriers" in the correct locations, then any moisture trapped inside the wall should naturally migrate towards the outside. That's why you have a vapor barrier (more correctly, a vapor retarder) inside the cavity, up against the surface that is warmest in winter (the inner-leaf, usually), and a breathable water barrier on the outside of the outer leaf. The vapor barrier is on the warm surface, so moisture cannot condense on it, and the water barrier prevents liquid water from getting into the wall from outside, but allows air to pass through, carrying with it any humidity that might be present. The way I understand it, this setup creates a gradient that tends to move moisture from inside to outside, naturally, in the air itself, and prevents liquid water from getting back in.

Beyond that basic concept, when I'm designing a studio, I leave things up to the local experts to decide on the details, based on local climate and local building codes.

You might find these helpful, though... if you ca decipher them!

https://archive.airbarrier.org/about/difference_e.php

https://www.buildingscience.com/documen ... r-barriers

https://www.energy.gov/energysaver/weat ... -retarders

The render coating is around 8mm in total (thin coat DPR Acrylic render by Parex) I assume this won’t have any detrimental effect on the MSM system by acting as a third leaf? The outer leaf is so massive I’m hoping there won’t really be much energy to resonate within the EPS!!!

Now this one I can help you with! Don't worry about it. Technically, yes, it is a third leaf, but in practice it's not going to do anything much to your isolation. EPS is closed cell, it fills the space totally, so there's not really any air spring to speak of. It is low mass, and fairly rigid, so it's not going to act as a spring or a mass itself. And 8mm of render coating on the outside of that, compared to a massive 300mm concrete wall, 70mm away on the other side of the EPS, is not an issue to be worried about.


- Stuart -

[mola1000]

Drawing near to beginning this manufacture, I simply needed to elucidate that I am wanting to utilize this room as a multipurpose space, recording drums and other live acoustic instruments just as blending down as in a control room setting. I realize that for a live room you would need distinctive acoustics to a control room so I am intending to go for a control room condition which I can record in and include live ness carefully.

I don't have enough space for 2 rooms so I am building one great one!

[Soundman2020]

Drawing near to beginning this manufacture, ... !

Please do not hijack other people's threads. Start your own thread.

Also, please read the forum rules for posting (click here). You seem to be missing several things...

- Stuart -

[mola1000]

Drawing near to beginning this manufacture, ... !

Please do not hijack other people's threads. Start your own thread.

Also, please read the forum rules for posting (click here). You seem to be missing several things...

- Stuart -

I realize that for a live room you would need distinctive acoustics to a control room so I am intending to go for a control room condition which I can record in and include live ness carefully.

[SPAM LINKS REMOVED - SPAMMER BANNED AND BLOCKED]

[Purelythemusic]

Waste man spammer

Thanks Stuart, our VCL is usually only used on timber framed buildings on the inner frame before the drywall goes on/foil backed drywall...

We don’t commonly use them on purely masonry, so I’ll possibly just use a waterproof scratch coat for the inner room render and leave the vapour permeable render on the outside of the EPS.

Thanks for all your thoughts and help!

Almost finished the house so can think about starting soon!

Got the living room set up with a decent hifi which i’ve been missing for years! I’m hoping to treat the back wall with decorative panels and behind the ported speakers in a cabinet!!! but the Mrs keeps insisting it’s just a living room? The speakers are in a poor location but safe from toddlers fingers!

[Purelythemusic]

Living Room pic

[Gregwor]

Run a REW test on your living room. I'm curious!

Greg

[Soundman2020]

Run a REW test on your living room. I'm curious

+1

- Stuart -

[Soundman2020]

The speakers are in a poor location but safe from toddlers fingers!

Ahhh, yes, ... but toddlers do seem to have a habit of getting taller, way faster than you expect! And they are also quick at learning to climb on top of stuff, to reach fascinating black rectangles with intriguing soft squishy circles in them....


- Stuart -