Wall construction for home office/studio

[John McClung]

Hi folks, rookie here asking for input/feedback on smart way to plan wall construction for my new office/studio; studio use will be very light. My main goal is just decent sound management, not pro studio soundproofing. Please see attached PDF for what I've been planning.

Questions: per some of Rod Gervais' comments around the web, it seems that if my inner room-within-a-room walls are already decoupled from the structure's outer wall (staggered studs on a common baseplate), then also adding Genie Clips and hat channel is overkill. True?

Am I creating any problem with that layer of Type X drywall on the inner facing of section A, the structure's wall?

Comments on the section C plywood (for hanging wall art, etc.) / Type X drywall / Green Glue / QuietRock ES drywall ?

Thanks for educating me. All I know is what I've read, so I'm hoping to validate my thinking (or refute it) before the build begins.

[Paulus87]

Hi folks, rookie here asking for input/feedback on smart way to plan wall construction for my new office/studio; studio use will be very light. My main goal is just decent sound management, not pro studio soundproofing. Please see attached PDF for what I've been planning.

Questions: per some of Rod Gervais' comments around the web, it seems that if my inner room-within-a-room walls are already decoupled from the structure's outer wall (staggered studs on a common baseplate), then also adding Genie Clips and hat channel is overkill. True?

Am I creating any problem with that layer of Type X drywall on the inner facing of section A, the structure's wall?

Comments on the section C plywood (for hanging wall art, etc.) / Type X drywall / Green Glue / QuietRock ES drywall ?

Thanks for educating me. All I know is what I've read, so I'm hoping to validate my thinking (or refute it) before the build begins.

Hi,

So looks like your outer wall is a coupled double leaf wall, then a 2” air gap and then another double leaf wall using staggered studs?

This is a 4 leaf system. You should remove the inner two leaves, get rid of the staggered stud configuration, and use the mass you removed And put it on the outer most leaf and the inner most leaf.

That will increase your transmission loss all the way down to the low frequency end of the spectrum and give you much better overall performance for your wall assemblies.

Genie clip is not required if you have a fully decoupled two leaf system (which is what you’ll have if you do as instructed above).

How is your floor constructed? If it’s a concrete slab on grade then that’s good and you should leave it as is.

You need to construct your ceiling and roof assembly much the same way as I stated above, except if you have a cold roof design with vents then you’ll add an extra “leaf” but I’ll help you more with that once you reply.

Also just use the cheapest mass you can get which is designed to do the job at hand I.e just drywall x @5/8” should suffice for all your layers, you can use ply as well which will be your structural sheathing to help tie all your studs together.

How much of this is already built?

Paul

[John McClung]

Hi folks, rookie here asking for input/feedback on smart way to plan wall construction for my new office/studio; studio use will be very light. My main goal is just decent sound management, not pro studio soundproofing. Please see attached PDF for what I've been planning.

Questions: per some of Rod Gervais' comments around the web, it seems that if my inner room-within-a-room walls are already decoupled from the structure's outer wall (staggered studs on a common baseplate), then also adding Genie Clips and hat channel is overkill. True?

Am I creating any problem with that layer of Type X drywall on the inner facing of section A, the structure's wall?

Comments on the section C plywood (for hanging wall art, etc.) / Type X drywall / Green Glue / QuietRock ES drywall ?

Thanks for educating me. All I know is what I've read, so I'm hoping to validate my thinking (or refute it) before the build begins.

-----------------

So looks like your outer wall is a coupled double leaf wall, then a 2” air gap and then another double leaf wall using staggered studs?

This is a 4 leaf system. You should remove the inner two leaves, get rid of the staggered stud configuration, and use the mass you removed And put it on the outer most leaf and the inner most leaf.

That will increase your transmission loss all the way down to the low frequency end of the spectrum and give you much better overall performance for your wall assemblies.

Genie clip is not required if you have a fully decoupled two leaf system (which is what you’ll have if you do as instructed above).

How is your floor constructed? If it’s a concrete slab on grade then that’s good and you should leave it as is.

You need to construct your ceiling and roof assembly much the same way as I stated above, except if you have a cold roof design with vents then you’ll add an extra “leaf” but I’ll help you more with that once you reply.

Also just use the cheapest mass you can get which is designed to do the job at hand I.e just drywall x @5/8” should suffice for all your layers, you can use ply as well which will be your structural sheathing to help tie all your studs together.

How much of this is already built?

Paul

-------------
So you're recommending 2 layers of drywall on the inside of the structure's wall, none on the exterior-facing of the interior assembly, but double drywall on the interior-facing side of the interior assembly? Presuming using green glue between both double drywall layers, agree? Is there no real advantage to perhaps just using QuietRock ES vs Type X on the interior layer? ◼︎ Why do away with staggered studs, I read that that's an effective way to elevate STC. ◼︎ Floor is a concrete slab. ◼︎ Nothing is built yet, so now's the time for me to perfect my planning! Thanks for taking time to reply, Paul.

[Paulus87]

So you're recommending 2 layers of drywall on the inside of the structure's wall, none on the exterior-facing of the interior assembly, but double drywall on the interior-facing side of the interior assembly? Presuming using green glue between both double drywall layers, agree? Is there no real advantage to perhaps just using QuietRock ES vs Type X on the interior layer? ◼︎ Why do away with staggered studs, I read that that's an effective way to elevate STC. ◼︎ Floor is a concrete slab. ◼︎ Nothing is built yet, so now's the time for me to perfect my planning! Thanks for taking time to reply, Paul.

You should only ever have walls/ceilings constructed like the last assembly on the far right in the attached image.

You do not need a staggered stud wall as you already have a fully decoupled external wall. So let's just say in your current plan you have a double stud wall with an air gap in between, by having the drywall layers in the middle (inside the cavity) you are reducing that assembly's sound reduction significantly, by removing those middle layers and putting them on the outside face (closest to the outside world) of your external walls, and on the inside face (closest to the internal room) you INCREASE the sound reduction massively, and most importantly the cavity resonance will decrease (get lower) which is really what is most important. We really want to try and make our cavity resonance at least an octave lower than the lowest frequency of the monitors to be used.

So, for example, if you used 2"x6" framing for both your external and internal shells with a 2" air gap that would give you 5.5"+2"+5.5" giving you a cavity depth of 13". You would fill that cavity with low density fluffy loft insulation.

For the panels on the frames you can use whatever you like, green glue is usually not needed. A very simple way of doing it would be as follows: For your inside face you could use a layer of ply or OSB plus 2x layer of 5/8 drywall X, for your external face you could use a layer of OSB and weather resistant fibre cement board (the cement board will be your final layer facing the outside world).

Provided all layers were sealed with no holes, and you built it on a concrete slab on grade, this would give you very good isolation all the way down the frequency spectrum. If you haven't seen it already you should check out Greg's MSM TL Calculator... there's a sticky in the forum. You can use it to experiment with different materials and air gaps in order to assess how well your preposed assembly will perform, and what frequencies will be reduced as well as what your cavity resonance will be. BUT the assembly I detailed above will work just fine, there really is no need to go further than that unless you need to use different materials or you need extreme isolation at 20hz and below.

Paul

[Paulus87]

One more thing, since nothing is built yet and providing you have the ability to do so I would recommend a main concrete slab on grade surrounded by a decoupled perimeter slab. You would build you internal walls on the main slab, then your external walls on the perimeter slab.

This is not really needed in most situations, but since you have the opportunity to build from scratch it's something to consider as it will decrease flanking and improve your overall transmission loss.

You could fill the gap between the perimeter slab and main slab with expanding foam, a rubber expansion joint or caulk... whatever will stop damp from rising up (as well as insects) but still maintain isolation between the two.

Paul

[xSpace]

More information is required to build this room.

https://www.dropbox.com/sh/ztp08qrg9swu ... U55wa?dl=0