Replies

1. 
   4Lorn2 | Dec 25, 2003 06:30am | #1

   Not a fire engineer but I do know that those poly panels catch fast, burn hot and emit gasses so toxic that a single deep breath of the smoke can cause unconsciousness in a matter of seconds. I get this from a few firemen I know. This stuff is good insulation and not a bad field expedient for napalm.

2. 
   Heatherington | Dec 25, 2003 06:41am | #2

   You need to go to both the fire code and the building code even to have a clue.

   I have studied the building code, just to see how it applied to the NEC, and that was an eye-opener. I found the sources of some rule I had long heard, but usually garbled. I have never tried to read the fire code, although, if I'm going to get back into construction, perhaps I should.

3. 
   caseyr | Dec 25, 2003 07:16am | #3

   Any insulating foam needs to be covered by at least a 15 minute fire barrier - usually  1/2 in. gypsum board, plaster, or similar.  Some polyiso advertising claims that it does not require a thermal barrier in some applications, but I believe current fire codes call for covering all foam insulation in interior applications with a 15 minute fire barrier.  There are particular restrictions in any area where welding is taking place around exposed foam. 

   I found the following article (and one that it references) to be an intersting read:

   http://www.monolithic.com/plan_design/fire_hazard/index.html

4. 
   MojoMan | Dec 25, 2003 04:19pm | #4

   I live not too far from Warwick, RI where 100 people died in a fire in a club last winter because there was sound-deadening foam on the walls and ceiling. I imagine your idea would encounter some resistance.

   Al Mollitor, Sharon MA

5. 
   KRettger | Dec 25, 2003 05:40pm | #5

   Merry Christmas Paul Ben,

   I have a few questions about your project. First I would be concerned about fire. You need to follow up on the other posts on this thread but I think the answer you are going to get it this thing would go up in flames like a gasoline soaked rag.

   Second question is what is the purpose of this "drop ceiling". Is it a thermal or acoustical barrier? What are the dimensions of your ceiling and how high is it? What is it made of, and what is it's R-value? I ask this question because I wonder what type of gap or reveal you will have around this contraption. To be able to raise and lower this device you will need some open space around the edges of it and it would seem that would negate a lot of the value of this movable ceiling.

   Lastly you have not explained how you would construct the studs to themselves. My assumption is that you plan on using 25GA. studs on 12-16" centers and screw them in 6" 25GA. track running 16' long. I have a lot of experience building with steel studs and I have to say this thing will sag in the middle real bad. If you are going to do this you need to stiffen the track so as to stiffen the construction as regards the track flexing. To accomplish this you can go about it in a number of ways. One is to add a box beam to the on all four sides. To do this screw another piece of track face to face with the existing track, and then nest a stud inside this new piece and screw it together. This will form a box beam and give you much more strength. Secondly you can rip 3/4" plywood and laminate it to the track to stiffen it. Third, you can also install a stiffback to the track to stiffen it. Lastly you can combine all of these to truly get a rigid piece of construction. Remember to give the track an overlap splice of at least 12" when connecting them to themselves to get your 16' length.

   I hope you are not building a "death trap" with this project. Perhaps a more conventional approach to this ceiling would give you the results you desire but without the liabilities associated with your original idea.

   Anyway I wish you a lot of luck, and hope this project turns out all right for you. It's been awhile since I've come across a post this original.

   Happy New Year,

   Cork in Chicago

1. 
   workalone | Dec 26, 2003 11:38pm | #6

   Cork,

   Thanks for all the good observations, especially about the steel studs sagging in the center.

   First, to answer the question of why do I want to do this. My house will be single story, 30'x30', no interior columns. The roof peak is 16' high. In the summer, it would be nice to have the full 16' open to create a cathedral cieling and to give a feeling of airiness. But in the winter I'd want to make the ceiling more cozy. This "hinged panel" idea would allow me to hoist the panels up with a rope and pulley, or lower them to a normal horizontal position.

   About the sagging steel - I'll probably connect two 6" studs together, creating a 12" deep stud. Youre right about the corners being uninsulated. My plan is to insulate the corners with thick foam rubber sheets, the kind that bed matresses are made of. The foam would stretch or compress as the panels are lowered or raised. If they stay compressed for long, they will probably take a set, but should rebound over a short time.

   PaulBen

   l

1. 
   KRettger | Dec 27, 2003 02:32am | #7

   Hey Paul Ben,

   I understand what you said about connecting two 6" studs together. If you try this you will find it hard to do. First the studs are a C type shape with a lip or flange on them. As they are exactly the same dimension they will not want to "nest" together, and if you try to screw them to each other it ain't easy. A box beam is much easier to build and stronger in use. In your original post you stated you would build this panel out of 6" studs. I assume you are going to use 8' studs and secure them in 6" track at the top and bottom of the studs to form a rectangular panel. Once you do this (remember to fasten both flanges of studs with screws to track at both "top" and "bottom" sides of the panel so the studs don't twist), and you have formed your rectangular panel then just take another piece of track and fasten it back to back with the existing track. Then take a stud and slid or nest the open or soft side of the stud into the open flanges of the new track. Then screw through the track flanges into the stud  about every 12-16". This will then create a "box beam" which is very strong and will not flex or sag in this application.

   Believe me Paul Ben when I say this is easier and stronger.

   Anyway, lots of luck and hope it works. Post a picture of it when you are done.

   Cork in Chicago

2. 
   caseyr | Dec 27, 2003 08:00am | #8

   When you talk about using matress foam, that leads me to believe that you didn't happen accross the article I posted last month showing the high propensity of mattress foam to burn furiously.  It is in post 36888.1

1. 
   workalone | Dec 27, 2003 09:29pm | #9

   Scratch the foam bedding idea.

   PaulBen

3. 
   GoldenWreckedAngle | Dec 31, 2003 07:08pm | #14

   It sounds like you have a pretty good application for Structural Insulated Panels for your roof. Your lowered ceiling in the heating months is a good, energy efficient concept, but the only way it will benefit you much at all is if you also lower the insulation barrier and figure a way to seal all the edges. Ceiling fans that push the rising warm air back down where it will benefit you the most might be a much better bang for the buck.

   Anyway, I like the way your thinking - just need to work the bugs out. There are lots of bugs but I wouldn't drop the idea just yet. There may be ways to make it work.

   Now, as for lowering the ceiling for visual reasons only, that is a bit easier to pull off.

   I don't know how contemporary you are willing to go with this space but if you just want to alter the feel of the space by lowering the perceived ceiling height during certain times of the year you could use perforated metal panels over a cable grid  attached to eye bolts on the walls and ceiling at 4'-0" O.C. both ways. It would probably be a real pain to put it up and take it down very often though.

   Alternatively you could weld up aluminum frames with perforated panels that could be raised and lowered pretty easily by cable. Keep in mind too that varied ceiling heights are far more interesting than a single height ceiling, or even a vaulted ceiling over an entire space. You might consider just suspending panels over certain seating areas to add more interest to the entire space and give a more cozy feeling to certain areas.

   One trick I like a lot is to backlight a perforated panel suspended over an area to cast a shadow on the floor that helps distinguish the space from those around it without adding walls or altering the floor treatment. Under a large vaulted ceiling it sort of creates the feeling of sitting under a shade tree with no trunk. Task lighting in the form of lamps or tracks can be added to remove the shadow in the space where it isn't desired. Very cozy!

   The dropped insulation barrier idea is an interesting challenge, but even if you can figure a way to raise and lower a fully insulated ceiling I would still encourage you to go with SIPs on the roof. That insulation barrier at the outermost surface of your building envelope will be a nice back-up to any shortcomings that may be present in the insulated ceiling. Good luck!Kevin Halliburton

   "I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity."  - I.M. Pei -

1. 
   workalone | Jan 01, 2004 04:40am | #15

   Kevin,

   Thanks for the excellent advise. Generally, I've come to the same conclusions as you.

    I'm now tending toward fixed insulated panels attached to the vaulted ceiling, and decorative mobile panels of metal or fabric that are affixed with cables/turnbuckles or even bungee cords pulling on each corner of the panel. No interior walls - just bookcases and armoires on wheels that can be pushed around to define areas. Love your idea about the perforated panels; you sound like a practicing architect.  Anyway, two architects looked at my models and drawings at a party. The main thought that they both conveyed was to be true to the material. My house is a metal folded plate structure, and it wants to be a spin on loft living / industrial design, with a twist of Phillipe Starck, whom I adore. Since the shape of the house is such a basic geometric one, the outbuildings will also be basic geometric forms, as if a giant child had been playing with wooden blocks and left them lying around on the grass.

   A few more thoughts:

   Ceiling - Since the ceiling is curved, I'll probably attach SIP's to  it, then cover the SIP's with 3'x10' sheets of painted metal roofing; The panels are cheap, light, fireproof, and will easily bend along their long axis to conform to the vaulted shape.

    Windows - I can't afford expensive insulated glass, so I'll build sandwiches as follows: two layers of glass in a home-made frame. In between the sheets of glass will be two sheets of Plexiglass. The Plexiglass will provide insulation, and the glass will protect the plexiglass.

   Paul Ben

1. 
   DanH | Jan 01, 2004 04:57pm | #16

   I think if I were doing something like this I'd consider the steel frame with a "suspended ceiling" suspended below it. The thicker ceiling panels offer a fair amount of insulation, and you can then stack fiberglass on top and top off with a poly or Tyvek infiltration barrier. To seal the edges you an build a coffer around the edge of the room, and lower the ceiling down onto that.

   However, there's still a "gotcha". If you live anywhere north of, say, Tennessee then humidity infiltration into the area above the ceiling is apt to cause condensation up there, with mold and water damage resulting. You can vent the area to the outside to prevent this, but then you'll negate a lot of your insulation benefits.

6. 
   Piffin | Dec 27, 2003 11:34pm | #10

   Hello again paulben,

   The size panel you describe will be four sheets of 4x8 foam and not two. My thopughts on this project are already mentioned ny others - that you need a sheetrock cover finsh over the foam and that the edges will not be sealed and will let heat through. in summer, if you lower it, you will be experiencing high heat in the living area from sun heating the steal skin and then radiating into the interior.

   Also, I haven't done any calculations but I would expect this panel to weigh more like 80-100#

   I have installed custom fabricated panels that were designed for acuoustic and fire retardency. The company that makes them will not go to larger than 50 sq ft for each because it will sag in the center.

   .

   Excellence is its own reward!

1. 
   workalone | Dec 28, 2003 03:27am | #13

   Piffin,

   In principal you are correct. If sheetrock is used to protect the foam panels, the weight will be too great for a moveable 8x16 panel. My thinking now is to affix the insulation to the cieling normally, and build moveable panels that contain no insulation; their purpose would be just to alter the feeling of the enclosed space - make it larger or more cozy.

   PaulBen

7. 
   redlead | Dec 28, 2003 01:49am | #11

   Paul!! Bet you're a good mechanic.........but.......Don't do it. Hang fisherman's nets or paint murals or build an experimental airplane. Turn down the heat. Install a fan and knit a sweater. And good luck. Jim L

1. 
   workalone | Dec 28, 2003 03:20am | #12

   Paul!! Bet you're a good mechanic.........but.......Don't do it. Hang fisherman's nets or paint murals or build an experimental airplane. Turn down the heat. Install a fan and knit a sweater. And good luck. Jim L

   Well I <already> own two experimentals (ultralights), but I do need to rethink my concepts after hearing the feedback from this group.

   PaulBen