Studio door question

[Velvet Elvis]

Hey gang,

Just a quick question about doors... we have 6 panel "classic" style hollow core doors in our house. Obviously, these wouldn't be very good for the studio area that I'm building, so I asked the door manufacturer to give me some options.

He can provide metal exterior grade doors with complete weather stripping but he also said he could provide me with solid wood doors with complete weather stripping (since they are being custom built).

The wood doors would be 6 panel like the other doors, which I assume means it would have a weak spot sound wise where the styles meet the interior panels.

What would you suggest? would a heavy wood door with 6 panels be far better or far worse than a metal door if both have complete (all 4 sides) high quality weather stripping?

He said he can manufacture the doors for under $200 each (including having them factory sanded and painted).

Jim
Velvet Elvis

 

[Track Rat]

Hmmm. No suggestions but I can tell you what I did and it worked out pretty well. My outside doors into the studio (two) are exterier type pre-hung metel doors which I glued sonex type foam to and they work well enough there. I used another of the same type between the control room and studio but later added a second solid office type door (1 1/2" solid partical board with wood venier) opening the other way. The second door made a HELL of a difference in transmission.

 

[Supercreep]

Steel doors are filled with styrofoam, or something like it. Fairly light.

I had one temporarily. It resonated like a drum.

You want a solid wood door without figuring or "panels".

 

[RICK FITZPATRICK]

You want a solid wood door without figuring or "panels".

Hey Jim, it all has to do with what your isolation needs are and the EXISTING wall assembly construction that the door is going into. Its called WEAK LINK SYNDROME. Why put up a solid core door if the adjacent wall assembly construction is rated LESS than the door.

If you can tell us some more about what you are trying to do, isolation wise, and how your studio is constructed in relationship to the adjacent spaces/exterior, and where these doors lead...maybe even a floor plan, it would help sort this out. But yea, a solid core door certainly is the way to go, IF the existing construction is viable. For instance, if your floor or ceiling construction is a flanking path directly under or over the walls...well, whats the point then. Although, it certainly wouldn't hurt to use a solid core door if your budget doesn't mind, even though it might be overkill.

On the other hand, if your studio envelope is highly isolated, to match the Transmission loss of adjacent assemblies, you may even have to ADD mass to a solid core door to bring up its rating. i.e. ...the door COULD be a weak link even being solid core. This is where info is king. Also, the jamb, seals, thresholds, caulking, decoupling and other issues may be relevant as well. Especially if your studio is built using Resiliant Channel to decouple the drywall.(Note that jambs built into walls with RC decoupling need DECOUPLED casings to keep from shorting out the RC or tieing TWO leafs togeather of a staggered stud assembly)

fitZ

PS. Doubling doors in the same jamb can help as well, although if they are hollow core...they become QUADRUPLE leaf...which is WORSE(at some frequencies) than a single hollow core door. Don't ask me to explain. The reason TWO doors work better is the assembly becomes a TWO LEAF ASSEMBLY. As long as the airgap is sealed(jamb and threshold seals)

 

[undergroundtoon]

..........LOSS OF WORDS......nevermind

 

[undergroundtoon]

Nah.......

 

[Supercreep]

What Rick said.

 

[Velvet Elvis]

Rick,

Thanks for the post... I forgot that not everyone knows where I am at with the studio... hahaha

The studio is being constructed in an unfinished basement. It is regular 2x4 framing tapcon'd to the floor, but all of the walls (not drywalled yet) will be 2 layers of 5/8 inch rock on top of resilient channel. The floor is concrete.

The entry way into the studio is actually an airlock and will therefore have two doors (one on either side of a small room).

The drum room/isolation room is separated from the tracking room wall (IE - its stud wall is 6 inches or so away from the control room stud wall) and will therefore have two doors separating those areas as well.

If you look at the pictures attached, you'll see a view looking toward the studio entrance, a view of the airlock and then a view of the walls on the outside of the control room and the drum room.

Thanks,
Jim

 

[RICK FITZPATRICK]

It is regular 2x4 framing tapcon'd to the floor, but all of the walls (not drywalled yet) will be 2 layers of 5/8 inch rock on top of resilient channel. The floor is concrete.

Cool. I thought thats what you were doing. Alzheimers hasn't fully developed yet. Well, since your wall assemblys are using RC, think about what I said in regards to the casings. Also, you should consider building custom jambs to allow an extra 1/8" of jamb past the drywall so the casing does NOT touch the drywall. It should be caulked to the drywall Also, you might consider adding a layer of 3/4" MDF on each side of a solid core door, which if you do, think about using HARDWOODS for your custom jambs. This is not only for the weight of the doors and screwholding power, but to allow you to step the MDF for double door stops. And don't forget to stagger the drywall joints at the corners(wall and ceiling) and caulk each joint prior to laying up the next layer of drywall. And use a storyboard to mount your RC. That way you get precise layouts so you KNOW where the RC flange is. Don't want to short out the RC by screwing the first or second layer into a stud.

Another suggestion is to run the first layer of drywall vertically and the next layer horizontally. You might want to think about using GREEN GLUE between layers of drywall. Its expensive but well worth the money. It makes two layers of 5/8" act as one layer of 1 1/4".

And don't forget to allow a 1/4" gap at the floor and use a foam backer rod behind resiliant or butyl caulk. Remember too, INEXPENSIVE caulk is fine as long as long as it has a long term resiliancy.

Now, I'm not sure if the gap between the drywall and stud(behind the jamb and between rows of RC) are sealed with foam backer rod, but you might do that for extra iso as the only thing between those gaps and the casing is caulk.

And what are you doing on the ceiling Jim? Are you adding any mass to the underside of the floor above?(in between joists?) Are you using RC on the ceiling as well? Just curious. I'd post some pics but haven't got time right now. Later. Anyway, your project looks like its coming along just fine. Oh, one other thing. FIRESTOPS. Lets talk about that later too.

fitZ

 

[Velvet Elvis]

Cool. I thought thats what you were doing. Alzheimers hasn't fully developed yet.

We call that "some-timers" disease

And use a storyboard to mount your RC. That way you get precise layouts so you KNOW where the RC flange is. Don't want to short out the RC by screwing the first or second layer into a stud.

What do you mean by a storyboard? I'm actually having a drywall crew from a local company do the drywalling.. BUT I am doing all the caulking and setting them up with the specs and such on how to do it. They have done RC drywalling before (quite often for theaters and high $$ condos etc), which is one of the reasons I picked them. They did a bang-up job on the drywall in the rest of the basement (that didn't require any special treatment).

And what are you doing on the ceiling Jim? Are you adding any mass to the underside of the floor above?(in between joists?) Are you using RC on the ceiling as well? Just curious.

The ceiling will also be 2 layers of 5/8 on RC. I've thought about adding mass to the underside of the floor above, but its pretty difficult. I've got some real challenges there with holes for drains and such, so I'm not sure what exactly I'll do... but at the very least the lid of the studio will be the 2 layers of 5/8 on resilient channel. I'll attach some pics to show my problem areas.

The first pic shows a soffit that is SOOOO stuffed with pipes and such that I wouldn't be able to feasibly add mass to the floor above it.

The second pic shows some of the drain stuff I have to work around in the ceiling.

FIRESTOPS. Lets talk about that later too.

If by firestops you mean firestop putty pads on all of the outlets and such... that's already being taken care of. A local electrical supply house stocks them (the good stuff) and I'm using them!

I'm also using OSC-175 acoustical caulk, as its about the same price as regular caulk.

Last thing... I pulled insulation out of the exterior walls for use elsewhere, which means I need to buy new insulation. I've heard conflicting info as to whether regular "fluffy stuff" or rockwool would be advised. Some people say "always Rockwool and some people say its a waste of money for exterior walls behind resilient channel.

Jim

 

[RICK FITZPATRICK]

What do you mean by a storyboard? I'm actually having a drywall crew from a local company do the drywalling..

Howdy Jim. Well a storyboard is a board with a set of index holes or cleats, pegs, nails or what have you, that you can move from one location to the next, so precise alignment of whatever you are doing is consistant. In this case, I'd use a storyboard with cleats to align the vertical spacing of the RC so they are consistant from one area to another. Then using the same storyboard, with holes to align the screws to the center of each row of RC flanges or something to that effect. Remember the flange on the RC is only about 1/2" wide. Trying to guess or even marking lines on the drywall is pretty ...er, lets just say...not convincingly accurate. At least to my way of thinking. However, its a moot point since you're hiring a company. Let me ask you this though. How does one GUARANTEE NO screws short out to framing, OR all screws will enter the flange correctly? The ONLY proof is destructive. Hence, trust in their work is your only friend here. But I "would" ask them to demonstrate "their" plan of attack. Its only a suggestion though.

The ceiling will also be 2 layers of 5/8 on RC

Hmmm, to what are you attatching the RC. In one of the pics t looks like theres no joists. Only a brace of some kind. Are you hanging HAT CHANNEL to hang the RC from or something? Again, just curious.

The first pic shows a soffit that is SOOOO stuffed with pipes and such that I wouldn't be able to feasibly add mass to the floor above it.

Nevermind. You might not even need it with 2 layers of 5/8". I was just curious.

If by firestops you mean firestop putty pads on all of the outlets and such...

No, I mean in the walls and at the juncture between the walls and the flooring above. Since you are using RC, and this creates an air gap between the drywall and framing, typical firestops are useless. I've actually never heard anyone describe how this should be done, but I have read something about insulation meets code for firestopping somewhere. Maybe you should ask the "inspector"....er, you are having it inspected arn't..er...maybe I shouldn't go there.(memo to self...file under.."none of your business")

As to the insulation in the exterior wall....which I don't know why it would make a difference being exterior or interior partition wall, I'm under the impression that normal ole batt type insulation is fine. I don't know why Rockwool would make a difference. Hell, its only cavity insulation, so what the heck? Of course, my disclaimer is in full force here.

Anyway, looks like you know what you're doing so good luck and keep us up to date. Thanks
fitZ

 

[Rod Gervais]

Howdy Jim. Well a storyboard is a board with a set of index holes or cleats, pegs, nails or what have you, that you can move from one location to the next, so precise alignment of whatever you are doing is consistant. In this case, I'd use a storyboard with cleats to align the vertical spacing of the RC so they are consistant from one area to another. Then using the same storyboard, with holes to align the screws to the center of each row of RC flanges or something to that effect. Remember the flange on the RC is only about 1/2" wide. Trying to guess or even marking lines on the drywall is pretty ...er, lets just say...not convincingly accurate. At least to my way of thinking. However, its a moot point since you're hiring a company. Let me ask you this though. How does one GUARANTEE NO screws short out to framing, OR all screws will enter the flange correctly? The ONLY proof is destructive. Hence, trust in their work is your only friend here. But I "would" ask them to demonstrate "their" plan of attack. Its only a suggestion though.

As usual Rick, sound advice.

As long as you don't let them tape before you inspect - it's pretty easy to verify that there aren't any shorts - you should always locate studs before placing any drywall.....

No, I mean in the walls and at the juncture between the walls and the flooring above. Since you are using RC, and this creates an air gap between the drywall and framing, typical firestops are useless. I've actually never heard anyone describe how this should be done, but I have read something about insulation meets code for firestopping somewhere. Maybe you should ask the "inspector"....er, you are having it inspected arn't..er...maybe I shouldn't go there.(memo to self...file under.."none of your business")

Actuall - the firestop is still there - you just aren't picturing it -

Fire stops are intended to stop the vertical passage of flame - and the top resilient channel is supposed to nail directly to the top plate (or to a row of continuous solid blocking) - and thus it is the resilient channel itself that creates the fire stop.

Rod

 

[Rod Gervais]

Last thing... I pulled insulation out of the exterior walls for use elsewhere, which means I need to buy new insulation. I've heard conflicting info as to whether regular "fluffy stuff" or rockwool would be advised. Some people say "always Rockwool and some people say its a waste of money for exterior walls behind resilient channel.

Jim - save your money and use the cheap fluffy stuff........ believe it or not - if you study IR-761 - you'll find that the best overall performance at Low Frequencies is the fluffy stuff - with a loss in that range and gains in the mid and highs with the rockwool.

Seeing as dealing with the mid and highs is automatic - you should always go with what improves low frequency TL values.

The people who swear by the rockwool (flying in the face of the actual scientific results of which they are probably not aware) probably think that because they know that added mass is what you want for Low Frequencies........ and it is - but only on the wall faces.......... not inside where it affects the air-spring.

Rod

 

[Velvet Elvis]

Rick and Rod,

You guys are awesome!!

I am indeed having every step of the way inspected by the city. EVERYTHING (that requires a licensed contractor) is being done by known, licensed contractors and inspected by the city.

I've got a great working relationship with the inspector that does my neighborhood and he's been great with pointing things out and letting me know where I have some flexibility with codes etc. NOTHING that would be hazardous however, more along the lines of locating tub drains with molding and such versus having to have cut out access to them etc.

The inspector is well aware that I am doing 2 layers of 5/8 on RC and has no problem with it.

The RC will be hung directly on the bottom of the joists with the exception of the areas around the soffits (the soffits with the utilities in them, not the speaker soffits). They are technically below regulation height, so the framing contractor used 2x4s and 2x6s on their side connected to OSB to keep the ceiling height high enough. They are short spans and anything longer than a couple feet was done with additional suspended support from the ceiling (I'll see if I have pictures).

My total ceiling height at the soffits after the drywall and RC is like 6'11". Code is 7', but the inspector said that as long as you are making best effort to meet the 7', they don't complain.

So... do you guys recommend the fluffy stuff in the interior walls for the same reason? (better bass TL values).. remembering that I have two walls (separated by an air gap), is there any value to using a combination of the stuff? Will it stand up in the wall better (since the inside of the wall would still be open)?

Thanks guys... this is helping a ton!!

Tile went down in the bathroom this weekend!!! Toilet and sink get installed this next week (once we seal the grout). Doors for the none studio portions arrive mid week... YEAH!!!

Jim

The first picture shows one of the soffits (along the back wall). It consists of OSB that is stapled to the joist to drop down below the soffit. There is then a 1x1 stapled to the bottom and then the 2x4s and 2x6 that span below the soffit on their side are connected to that. The contractor builds luxury homes here in town and does GREAT work. He showed me the strength of how the assemble it by hanging on just ONE of the 2x4s at center span... he's about 200 lbs and it held him fine.

The second picture shows a cool toy that a friend of mine donated to the studio. Its an industrial air handling computer. He's outfitted the studio with temperature sensors and fully sealing electronic valves on all the air feeds into the studio and the air returns. It will monitor the temperature and open and close the valves accordingly. While in session, I can override them to either stay open or seal up completely, closing the AC off as a place of transmission. This system was taking out of a hospital and was being thrown out for being outdated, so I got it for free!!!

 

[Velvet Elvis]

Another major score for the basement/studio...

My father-in-law contacted a friend who happens to hang doors and windows for a living... he has offered to come hang all the doors in the basement... for free.

He also said when I was ready for the doors in the studio, he'd hang those too... again for free.

17 doors total!

Not that I couldn't do it, but this guy is good and fast. He did all of my father-in-law's basement in a matter of a few hours.

Jim

 

[ZeroInt]

Just to chime in about your doors really quick...

I would contend that a metal door COULD be better. It just depends whats in it. I think I saw somebody suggest styrofoam may be in it...if thats the case, def the solid wood door.

Also something else to think about...

Is the "weather stripping" a pile type or rubber (neoprene and silicone being the better suspects usally)?

 

[Velvet Elvis]

It would be rubber weather stripping... and I'd probably have them make a couple rows of it for a tighter seal.

Jim