A wall on a wall?

[reprosser]

I had such a great response from my previous question - I decided to try another.

My next framing project is to build the wall to close off the "noise room" from the rest of the shop.
The wall will be about 10 ft wide - but 14 feet high.

Can I just build a - say - 8ft wall, and then build a 6 feet wall on top? 2x4 or 2x6 or?
I have a 6x6 treated post on each side to attach. You can see the opening (concrete has been poured since this photo) in the back corner next to overhead door. The room will be 10x12 with sloping roof.

Other suggestions?

 

[James Davis]

With double top plates tied into the upright supports that are there you should be OK, But wouldn't it be easier to measure the length of the studs needed and just build it with full length studs. There would be less flexibility in the wall. Just be sure to use a double row of purlins.

James

 

[Gotcha6]

For 14' high I'd go 2 x 6 - or metal studs. 8 & then 6' will work if you double the top plate of the 8' wall for strength. If you're planning on putting in a door of any consequence, why not frame the header all the way across with double jack studs on each end, then take the studs to the roof over the header timbers? You could then close in the header to whatever door you like & even make a wider door later if you so choose.

 

[DaveD]

Personally I'd do the 14' in one shot with 2x6 lumber. Besides it will be twice the work to build two walls as it will the one tall one.

 

[skysharks]

I would have to agree with one build. From your photo looks like the roof system slopes up away from your area. So I would build it in one piece and slide her in place.
You can frame it with 2x4 and it will work, but since your using this space for your "noise room" I would use 2x6 for the extra depth for insulation and sound proofing.
You also may want to double layer the sheet rock which would really help with the sound.
Don't forget to do something with the exterior walls that are metal clad, to dampen the vibrations from the sound.
Hope this helps

MAC

 

[reprosser]

I am planning to install one 36" door (center-ish) in the wall.

I will have to check to see if the cost of 14' (16') studs (2x4 or 2x6)would be higher than stacking two walls. Maybe there is not a big difference and it won't matter.

Then there is the raising of the wall issue. A 10 x 14 ft wall will probably be tough to raise by myself - would have to call in a few friends or rig up something.

Don't forget to do something with the exterior walls that are metal clad, to dampen the vibrations from the sound.

I had not planned to do anything with the metal walls...what kinda options would there be?

 

[Bigdog72]

For 14' high I'd go 2 x 6 - or metal studs. 8 & then 6' will work if you double the top plate of the 8' wall for strength. If you're planning on putting in a door of any consequence, why not frame the header all the way across with double jack studs on each end, then take the studs to the roof over the header timbers? You could then close in the header to whatever door you like & even make a wider door later if you so choose.

+! for versatility

Also remember that those metal walls could sweat on the inside when insulated. Take that into consideration.

 

[gdoebs]

If you really want to dampen the sound use 2 X 6 top and bottom plates, then alternate 2 X 4 studs from one edge to another. When you hang drywall on each side, the sound vibrations won't transfer through the walls. Basically build two 2 X 4 walls, one on each edge to the 2 X 6 plate.

 

[reprosser]

why not frame the header all the way across with double jack studs on each end,

IF I go this route, how would I build the header to span the 10 ft?

use 2 X 6 top and bottom plates, then alternate 2 X 4 studs from one edge to another.

I think I can use this technique with the 10 foot header span too!

 

[Gotcha6]

IF I go this route, how would I build the header to span the 10 ft?
Use 2 x 6s to build a box header. Two vertically between two 2 x 4s horizontally.
I think I can use this technique with the 10 foot header span too!

Yes, if you use 2 x 6s top & bottom on the box header. Another plus to the header method is you can use the top of the header as a temporary scaffold to install studs & sheathing on the upper part of the wall. Just chalk a line or tack up a straightedge on the upper studs at ~8'-1/2" off the floor for the sheathing and nail away. After the top is on, move down.

 

[max_in_graham]

Been rather "busy" as of late wiring the studio, doing the acoustic testing and actually recording some music, and FINALLY have some time to check in here...

If you really need to isolate the sound in the room from the rest of the shop, you have a few options... some of which can potentially be a waste of time... and money.

Depending on the nature of the noise, and how much you need to knock it down, there's quite a bit of a difference in how you approach the solution.

If you're needing to keep down the sound of a nail gun, it's quite a bit different than knocking down a floor model pneumatic hammer for steel work.

The real definitive method of isolating the noise is to define your noise. e.g. airborne or impact to the structure itself.

If it's loud and/or low frequency structural impact, and you must minimize the noise to make the wife or neighbor's happy, it's gonna cost a bundle, and you've got a LOT of work ahead of you.

If it's a dust collection system and a compressor, it's pretty darn cheap with a bit of extra work to keep that at bay.

I've just spent the last 5-1/2 years doing the former, and have been through a major wad of cash to achieve low frequency isolation in a professional recording environment, so I can tell ya... it ain't cheap to solve low frequency issues, and there are more ways to do it wrong, than do it right. :BangHead:

If you could post some details of what all is in your "noise room", I'll try to steer ya' away from the stuff I know doesn't work.

 

[reprosser]

Noise room is for ClearVue Cyclone and Air Compressor - so far.

 

[Gotcha6]

If you're going with the ClearVue, I'd suggest a 1/2 glass door to see it working!:eusa_danc Get it in insulated glass to reduce the noise or you'll be defeating the whole purpose of the insulated wall.

 

[max_in_graham]

Noise room is for ClearVue Cyclone and Air Compressor - so far.

WHEW!!

You get to come out cheap then!

First, a coupla' "rules"...

Rule #1 - Mass is your friend. The more mass the merrier.
Rule #2 - Wherever air goes, so goes sound.

OK, now that that's out of the way, we can get down to brass tacks.

You're not talking about much low frequency sound, really. So, you can use cheap mass to knock down most of the sound. I would use a 2x4 stud wall and take it from floor to ceiling.

Box your door header and fill it with insulation, with a 2x4 at the top and bottom. I know it's not much air space, but a solid header will transmit sound through the wall better than a boxed header.

Get a coupla' cases of good acoustic caulk, like OSI's SC-175 and caulk the snot out of every joint inside the noise room... floor, ceiling, stud joints, etc. You can use other caulks like painter's caulk, bu they get hard and crack... and a better chance for air to get through... but hey, it's a wood shop, right?

Then, fill the stud cavities with standard R13 insulation.

On BOTH sides if the wall, put up two layers of gypsum. The thicker, the better. (I'd go with 5/8", but that's just me.) Put the gypsum up leaving a tight 1/2" gap all the way around the edges.

Run a fairly thick bead of caulk in that gap, and while it's still wet, stuff 3/4" backer rod in there and put a sealing bead of caulk over the backer rod. Then seal the seams with a bead of caulk.

Snap a chalk line over each stud.

For the 2nd layer of gypsum, rotate it 90 degrees and put the gypsum up so that you're covering the seams. (Lather, rinse, repeat the caulk and baker rod around the perimeter.)

Finish the 2nd layer like you normally would.

I'd suggest using an exterior grade door with a bottom seal. They'll stop 95% of any air, and about 90% of the sound vs an open doorway.

stuff the sides of the door frame with insulation, as opposed to the spray insulation. The expanding foams break down after a coupla years, and after you've spent all this time and energy... why waste all that effort?

You'll have to go through the wall with your air line and dust pipes. So, I'd consider making up box framing, and putting plywood over/around the pipe, and caulk it, or use something like tub/shower liner material and caulk that.

Granted you don't really need to do the whole backer rod thing, but any vibration where the walls meet, sound WILL get through, unless it's air tight... the backer rod just helps minimize the contact points and gives you more area to caulk and know you've got it sealed.

For your gear, I'd make a coupla' wooden platforms, and place them on standard vibration isolators that is used to isolate air handler units in HVAC work. Start with 1 under each of the 4 corners, and adjust as necessary... by adding more isolators around the edge, as opposed to stacking them.

The thing you want to achieve is not over compressing the pucks, but get them in their most "springy" state. That way they aren't over compressed, nor under compressed.

 

[reprosser]

Wow!...and I thought I was doing good by just putting the noisy stuff in a separate room.
I don't need sound PROOF, but reasonable is OK. Max has some good ideas.

OK - planning to do the box header thing, and a 2x6 wall with offset 2x4 studs with insulation. Will apply one layer of gypsum (or OSB?) for now - maybe add more later. Caulk is good for joints. No idea what a backer rod is?

Planning to build a wooden frame for the cyclone, so it won't be attached to the wall. Air compressor is future purchase, so I will deal with it then. Wooden platform sounds like a good idea.

Now I just have to order a 1/2 insulated glass door :gar-La;

 

[Gotcha6]

Wow!...and I thought I was doing good by just putting the noisy stuff in a separate room.
I don't need sound PROOF, but reasonable is OK. Max has some good ideas.

OK - planning to do the box header thing, and a 2x6 wall with offset 2x4 studs with insulation. Will apply one layer of gypsum (or OSB?) for now - maybe add more later. Caulk is good for joints. No idea what a backer rod is?
It's a foam rod used behind caulk to fill in large cracks. It looks like a small gray pool noodle - same material in fact usually. comes in 50 - 100' rolls You'll find it usually in the paint dept. or with masonry supplies at the BORGs.

Planning to build a wooden frame for the cyclone, so it won't be attached to the wall. Air compressor is future purchase, so I will deal with it then. Wooden platform sounds like a good idea.

Now I just have to order a 1/2 insulated glass door :gar-La;

You'll find those at a BORG as well. They are usually stamped steel, foam filled, with a one piece light and optional mullions to divide it to a 6 light effect.

 

[McRabbet]

Rick,

I see that Dennis gave you an answer to the backer rod question (you can also find it in the weather stripping aisle at Lowe's), but I wanted to add some details of how I plan to erect my CV1800 to isolate any vibration from my walls or joists. Mine won't be in my shop either, but is in the highest part of the crawl space under my basement shop (I live on a hillside and have 9' of clearance under part of my shop). I poured a concrete pad in a corner of the space, adjacent to the foundation block walls. The ClearVue will be mounted to a stud frame on that pad and will be isolated from the foundation walls and the joists overhead. I'll use a bin sensor to determine when I need to empty the sawdust and plan to discharge the exhaust outside (although I have provisions to return filtered air to my unheated shop). I've attached a SketchUp rendering of the frame and cyclone (this version of the CV1800 I downloaded from the Google 3-D Warehouse has the blower reversed from what it should be).

View image in gallery​

I think you have seen my bin sensor threads on the ClearVue Forum. Obviously, a bin sensor is better (and cheaper) than a glass door!

 

[reprosser]

Yep, that is pretty much my plan. I think I downloaded the same model :icon_cheers
I will use 4x4s for legs. I have not decided on spacing for legs. I can go up 10-12 feet high (as high as possible), so I want to be stable while free standing. I have seen your posts, and will use bin sensor as well instead of glass door.

 

[Mark Anderson]

if you run across an old peice of carpet that you can put on the inside wall of the noise room it will help alot too.

 

[max_in_graham]

if you run across an old peice of carpet that you can put on the inside wall of the noise room it will help alot too.

Unfortunately, that's a myth... and one that just won't seem to die. Carpet is only good at absorbing very high frequencies and really doesn't have any acoustic value beyond that. It's also a heck of a fire hazard.

There are four things that stop sound in an enclosure... mass, absorption, isolation and lack of air movement.

Carpet only meets the criteria of absorption for a narrow band of frequencies. Generally from about 3kHz (thick wool or shag) on up, to about 6kHz for berbers... and up from there. Granted these are very annoying frequencies, but even regular R13 does a much better job at absorbing these frequencies at a cheaper cost per cu ft. and at a lower flash point.

There is a lot of data in the acoustics and vibration control industries that have established this, but it just hasn't seem to get out in the public awareness.