Replies

1. 
   DanH | Oct 17, 2007 05:56pm | #1

   I didn't know anyone still used rockwool.

   If your view never changes you're following the wrong leader
2. 
   ladyfire | Oct 17, 2007 06:16pm | #2

   I don't know a whole lot but this will help keep you at the top of the list.

   Blown fiberglass has a tendency to settle quicker than cellulose.  Also have seen tests done on the flammable issue.

   Fiberglass will burn once heated to  a specific degree, don't remember what that is.

   Cellulose will NOT burn near as easily. Saw a guy put a fresh batch of cellulose in his hand, put a penny on top of the cellulose, and melt the penny with a blow torch. While the edges of the cellulose did turn a charred color, it never caught on fire.  Also cellulose is treated with boric acid, therefore, hard shell bugs are not an issue later in the attic.  Cellulose is a wonder in that it literally fills all cracks and crevices.  The only draw back that most experience is a very fine mist of dust for the first 3 days.  After it settles, the problem goes away. I advise these clients to not dust for the first 3 days!

   I can't help you at all with rockwool.  We have never blown that.

   My DH wears the pants in the family. But I control the zipper!

    

1. 
   MMWWs | Oct 17, 2007 07:16pm | #3

   Hi, thanks for input. What little info I have gathered, is that anthything treated with Boric acid will off gas over time. How harmful this is I'm not sure?

1. 
   ladyfire | Oct 17, 2007 07:23pm | #4

   I wish I had more info to give you on this subject.

   I have never heard that boric acid gives off gas, not saying it's not true though.  We have blown cellulose in 100's of homes and there have been no reprocussions as of yet.  Earliest blown was 13years ago.

   My hopes are that if it is true, it's not too harmful cause that's what's in mine and I have more going in in a few weeks. :)My DH wears the pants in the family. But I control the zipper!

    

2. 
   andy_engel | Oct 17, 2007 07:44pm | #5

   Boric acid is slightly more toxic to humans than is table salt. It's hell on invertebrates, but most non-politicians handle exposure with no ill results. <G>

   Search on cellulose. It's a superior product to either fg or rockwool (each of which perform about the same).Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Book of Merlin

1. 
   ladyfire | Oct 17, 2007 09:26pm | #9

   Thanks for the save Andy.  I knew someone would be along to help! Guess I need to read up on my product knowledge.My DH wears the pants in the family. But I control the zipper!

    

2. 
   Piffin | Oct 18, 2007 12:13am | #20

   "It's hell on invertebrates, but most non-politicians handle exposure with no ill results. <G>"Bravo! I can't tell whether that is a pun or a double entendre or both interwoven!
   There is a thread here someplace I have to find for you where some squirrels and trees and such were the subject of about three hundred punsicles 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   DanH | Oct 17, 2007 08:28pm | #7

   Boric acid is one of the safest chemicals there is, only slightly more toxic than table salt. There is a danger of fertility problems with high concentrations, but you'd have to ingest tens of grams of the stuff in a reasonably short period of time for even that hazard.It's quite stable and doesn't "off-gas" to any significant degree since it's a crystaline solid in pure form.
   If your view never changes you're following the wrong leader

4. 
   Piffin | Oct 18, 2007 12:08am | #18

   borates are extremely inert. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   renosteinke | Oct 17, 2007 09:25pm | #8

   I beg to differ .... Backyard testing aside .... I can even get steel to flame and burn, given the right conditions ... fiberglass is far more fire resistant than any cellulose product out there. The industry test for this sort of product is ASTM E-84. I've described this test in other posts - it's enough to say here that it's a realistic and severe test. Fiberglass always comes in under "25,' a score that means essentially non-flammable.
   Cellulose requires extensive treatment, exacting quality control, and perfect installation to maintain this same score. Even the settling of the material during shipment will lead to wide variations in test results.

1. 
   DanH | Oct 17, 2007 09:28pm | #10

   Of course, settling make cellulose less flammable, not more.
   If your view never changes you're following the wrong leader

1. 
   renosteinke | Oct 17, 2007 09:34pm | #11

   Incorrect. The various parts of the cellulose have different densities. The additives that make the cellulose pass the test are separated from the cellulose ... so the stuff burns much more easily.

1. 
   DanH | Oct 17, 2007 09:50pm | #12

   I doubt if that effect could be significant. The borate treatment is soaked into the paper, and won't readily separate. I don't doubt that if you put it into a tumbler for an hour or two you could shake out a lot of the borate crystals, but that's not a realistic test.
   If your view never changes you're following the wrong leader

2. 
   Piffin | Oct 18, 2007 12:18am | #23

   Incorrect. borates will readily migrate through materials when moisture moves through them. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   renosteinke | Oct 18, 2007 12:35am | #26

   Again, 'data' trumps 'I think....' Actual tests, performed as a part of UL's follow-up testing, reveal chronic problems and wide variations with cellulose insulation. This is a very, very real problem with the manufacture of cellulose insulation, it's storage, and its' insulation.

3. 
   Piffin | Oct 18, 2007 12:07am | #17

   I have seen cellulose burn three times in the past thirty years so I don't have the same confidence in it that you do.BIBBs chopped FG will not settle when blown properly.
   They used to say the same about cells, until they learned the right density that give optimal insulative value and minimal settling. Same now applies to chopped FG.The rock wool is making a comeback. It is definitely fire-resistant. I am not familiar with it more t6han that though. I think it is slightly less R-value than the other two 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   JohnT8 | Oct 17, 2007 08:02pm | #6

   R values vary, but I would imagine they have comparable R per inch.  If the rock wool is true mineral wool, then it shouldn't have a problem with mold and wouldn't burn real easy.  Also I don't remember it making me itch like FG, but it has been a few years since I've had to handle it.  Seemed like it used to be dusty, but that might just be old rockwool.

    

   jt8

   "Those who wish to sing always find a song." -- Swedish Proverb

1. 
   Piffin | Oct 18, 2007 12:14am | #21

   makes me itch worse than FG 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   DanH | Oct 18, 2007 12:17am | #22

   The few times I've had a run in with (old) rock wool I've come out bleeding. The stuff has (or had then) large needle-like pieces that are really dangerous if you aren't careful.
   If your view never changes you're following the wrong leader

4. 
   frenchy | Oct 17, 2007 11:05pm | #13

   mmwws,

    I'd second what Andy said, Fiberglas is a lousy insulator, cellulose is better, Foam is best..

     Foam is also the most expensive.. however you'll have to do the payback calculation regarding foam versus cellulose.

     One caviot , If either Fiberglas or cellulose gets wet they make lousy insulation most foam is far superior if wet. 

1. 
   andy_engel | Oct 17, 2007 11:16pm | #14

   True, that.

   FWIW, I've gotten rid of scrap FG insulation by burning it with the scrap framing lumber. It ignites readily. I'm sure it's not the glass burning, the binders are probably the culprit, and the air space that makes FG insulate provides plenty of combustion air. Perhaps not all makes burn. I don't know that. Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Book of Merlin

1. 
   DanH | Oct 17, 2007 11:28pm | #15

   With the exception of some foams and a few ad hoc insulating materials such as cotton waste, the flammability of insulation is not a major issue. Insulation (if reasonable care is taken around can lights and metal flues) is rarely the first thing to burn, and it generally serves to slow the spread of fires that begin elsewhere by inhibiting heat transfer and drafts.I can't see that there's apt to be enough difference in fire resistance between the various insulation options (when applied to spec) to worry about. What's most important is following the install specs for the material used.
   If your view never changes you're following the wrong leader

1. 
   frenchy | Oct 17, 2007 11:58pm | #16

   DanH

       I'm not sure this fits with what you are saying.. Foam insulation has the advantage of not providing any combustion air,, fiberglas is great at providng air and some air is accesable with cellulose.

       One of the demonstrations I saw performed a number of times was the room made of SIP's they built a bonfire in the corner and got it burning.  The temp on the sheetrock was 1500 degrees while the temp on the outside of the SIP was only 50 degrees above ambiant..

    The bonfire eventually burned itself out without damage to the wall.. If that had been a typical stud wall the low R value of the stud would have transfered the temp to the point where air was accessable and then ignited. Wood burns at something like 800 degrees.

    ICF walls have a 2 hour fire rating.

1. 
   DanH | Oct 18, 2007 12:12am | #19

   It fits. In general, for residential applications, anything that can hold a fire back for even 10-15 minutes is usually going to be enough to allow the escape of the occupants, and, for safety margin, 30 minutes is a good bogey. The primary emphasis is on providing that escape time. There's no real need for a 2 hour rating, though certainly no harm in it.Fire of course spreads several ways -- conduction, radiation, convection, and traveling sparks, at least. Of these convection is likely the biggest hazard in a house fire -- once a fire gets going it generates strong convection currents. If there are no effective controls on convection (fire stops, fire sealing between floors, insulation in walls and ceilings, etc) then the fire will spread upward and outward at an astonishing rate, given just a modicum of fuel.
   If your view never changes you're following the wrong leader

2. 
   caseyr | Oct 18, 2007 04:02am | #28

   Fiberglass insulation is not considered a fire barrier. It will melt at around 1400 C (different formulations have different temperatures) and collapse. Before that happens, open nature of spun fiberglass lets the heat pass through. Polystrene has a flash temperature of 488°-496°C while polyurethane has a slightly lower flash temperature of 419 C. Thus either will burn vigorously above this temperature provide that there is sufficient oxygen.

3. 
   DanH | Oct 18, 2007 04:07am | #29

   But you don't need a fire barrier per se, but rather something that will slow the spread and, in particular, reduce convection. Just about anything that doesn't actively contribute to the fire will work.
   If your view never changes you're following the wrong leader

2. 
   andy_engel | Oct 18, 2007 03:21pm | #30

   Good points. I was only responding because someone mentioned the issue.Andy

   "Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)

   "Get off your dead #### and on your dying feet." Mom

   "Everything not forbidden is compulsory." T.H. White, The Book of Merlin

1. 
   caseyr | Oct 19, 2007 07:03am | #31

   Just for general interest, the following is from the FAQ on the NAIMA website, the association for manufacturers of (as might be obvious from the following paragraphs) fiberglass, rockwood, and similar insulations:"Cellulose insulation is made primarily of ground-up or shredded newspaper, which is naturally combustible. To protect against fire, cellulose insulation is heavily treated with fire retardant chemicals. Though cellulose is treated with fire retardants, it is not fire proof. This means the insulation could still burn if exposed to a heat source. Also some tests have shown that fire retardant chemicals can lose their effectiveness over time."Tests conducted by the California Bureau of Home Furnishings and Thermal Insulation demonstrated that most cellulose samples failed the standard fire safety test only six months after installation. Smoldering and re-ignition problems present additional concerns with cellulose insulation should a fire start."http://www.naima.org/pages/resources/faq/faq_fiber.html

2. 
   DanH | Oct 19, 2007 01:35pm | #32

   Of course, note that NAIMA is an organization of fiberglass manufacturers.
   If your view never changes you're following the wrong leader

2. 
   Piffin | Oct 18, 2007 12:22am | #25

   "I'm sure it's not the glass burning, the binders are probably the culprit"Will both FG and cellulose, part of the problem is that over time, dust settles into the material and the dust itself is flamable. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   Piffin | Oct 18, 2007 12:20am | #24

   "most foam is far superior if wet. "closed cell insulation simple will not get wet.
   Open cell insulation makes lousy insulation when wet 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   frenchy | Oct 18, 2007 02:04am | #27

   Piffin,

    I haven't seen much (read any) open cell foam being used around here.. that's why my caviot  Most..

   I know it has been used someplace.   I read where others have experianced it so I have to accept the fact that it exists.  But my experiance hasn't exposed me to it so I'll just have to continue to accept others word for it..