So here's what we've heard, J: when you get a fire in a room insulated with polyiso, the reflective foil keeps the heat inside, bouncing back and forwards between the walls, and it gets *really* hot really quickly. Once it reaches the gasification point of the polyiso sheets (literally the boiling point of the polyiso boards!) they go up *hard*.
I suspect in a full sized hexayurt that effect would take a while to build up and people have to walk a grand total of 10 feet to get out, so it's not likely a danger to life. But I worry that with a couple of thousand units deployed, eventually we're going to find this out the hard way. And as we see more and more large hexayurt complexes - are there adequate fire doors? Are tight-packed units all going to burn if one goes? I worry about these things. *All hexayurts should at least have a smoke alarm fitted. It's $10 and gives a real margin of safety. Could we try and get that standardized this year?* I think a pup hexayurt (remember woody's one sheet design) with a small camp fire inside would be a pretty good test at reasonable cost. The stuff certainly doesn't light easily, or I wouldn't have picked it, but law of large numbers is catching up with us. V> -- *Vinay Gupta * * hexay...@gmail.com <hexay...@gmail.com> * *http://re.silience.com* <http://re.silience.com> *Free Science and Engineering in the Global Public Interest* UK Cell : +44 (0)7500 895568 Twitter/Skype/Gtalk: hexayurt "In the midst of winter, I finally learned that there was in me an invincible summer" - Albert Camus On Mon, Feb 10, 2014 at 3:53 AM, Julie Danger <juliedan...@gmail.com> wrote: > About this fire issue: I've read some craaaaaaazy sounding specs about > fires inside hexayurts possibly reaching a bazillion degrees. Can anyone > back this information up? And, I'm considering a sacrificial research burn > at illumination of a small hexayurt to test this theory-- possibly Monday > post burn, 9 pm, illumination village, bring a lawn chair and some booze. > > > > *This from "hexayurt safety information" > <http://www.appropedia.org/index.php?title=Hexayurt_Safety_Information&action=history>* > Important safety notice. Please do not build hexayurts out of any > flammable material. This goes double for foam! In the past, people have > built them from non-fire rated materials including polyisocyanurate > insulation (Tuff-R from Dow, often sold at Home Depot.) I do not regard > that as safe if the building is exposed to sources of ignition like open > flame, or mains electrical devices. Any non-fire rated substance should not > be used for camping, and is generally suitable only for demonstration > purposes. > > Although free-standing foam may not burn well, an enclosure made of foam > can burn catastrophically. The foam traps the heat, reflecting it back to > the fire and quickly igniting the entire building. According to this > article <http://static.monolithic.com/foam/fire_hazard/index.html>, > temperatures can reach 10,000 degrees and buildings have literally been > blown apart by the sheer force of the flames. Warehouse-sized buildings can > be fully engulfed in under five minutes. The article is about urethane > foam, but polyisocyanurate will probably behave similarly. > http://static.monolithic.com/foam/fire_hazard/index.html > > Here is some video of a sheet of R-MAX (which is very similar to Tuff-R) > being set on fire. As expected, it does not burn well in open air. However, > this should not give a false sense of security about foam-lined buildings. > Foam manufacturers used to think their foam was "self-extinguishing" - but > in an enclosed space, it is not. > > http://www.youtube.com/view_play_list?p=36DB80EAF1D4161B > > (shot by Arthur Zwern of http://progressivebuildingsolutions.com) > > In addition, bidirectional filament tape has turned out to be > *very*flammable, and burns hot enough to ignite Tuff-R type insulation. This > is a > "negative synergy" - the two materials together are more of a fire risk > than either alone, because the fast-burning tape can ignite the boards. We > highly recommend covering all exposed filament tape with foil tape, which > is a few dollars a roll at Home Depot and similar places. > > > http://groups.google.com/group/hexayurt/browse_thread/thread/99fbdd6cf9ddaca8has > pictures of the test conducted by Spiral which revealed this problem. > Thanks, Spiral! > > Estimation of fire risk for any given situation is a decision that only > the person building the hexayurt can make. I recommend you watch the video, > get a clear sense of what's going on, and make your own judgments. All we > do is make the information available, and you make the decision. Please, > put in the extra work and source the safest possible materials. This is > your responsibility. > > > > > On Wed, Feb 5, 2014 at 7:09 AM, <hexayurt@googlegroups.com> wrote: > >> Today's Topic Summary >> >> Group: http://groups.google.com/group/hexayurt/topics >> >> - Bulk purchasing Thermax HD or other fire-safe hexayurt >> materials<#14419edb218e1010_14402989566b940b_group_thread_0>[1 Update] >> - framed hexayurts <#14419edb218e1010_14402989566b940b_group_thread_1>[1 >> Update] >> >> Bulk purchasing Thermax HD or other fire-safe hexayurt >> materials<http://groups.google.com/group/hexayurt/t/f32ad9329f47d272> >> >> Lance Culp <lanc...@hotmail.com> Feb 05 12:30AM >> >> Date: Mon, 3 Feb 2014 23:34:13 -0800 >> Subject: Re: [hexayurt] Bulk purchasing Thermax HD or other fire-safe >> hexayurt materials >> From: neversph...@gmail.com >> To: hexayurt@googlegroups.com >> >> Sound like a plan. Any ballpark idea of what the minimum order would >> be? >> On Feb 1, 2014 8:13 AM, "Richard Ginn" <richardg...@gmail.com> wrote: >> >> Let's make a list of all the suppliers and what their minimum order >> is, and what price breaks we would get at what volumes of purchase. >> >> >> >> >> >> On Sat, Feb 1, 2014 at 9:06 AM, Vinay Gupta (Hexayurt Shelter >> Project) <hexay...@gmail.com> wrote: >> >> >> >> >> They're tougher. >> They're not that much more expensive. >> They won't catch fire. >> I feel like this would be a great year to actually fix the supply >> chain issues around Thermax HD (or equivalents from other manufacturers), >> do a container load bulk purchase, and start moving people off R-MAX etc. >> until there's a comprehensive solution for the fire risk. I really want to >> solve this problem before somebody gets hurt. >> >> >> >> >> http://www.appropedia.org/Hexayurt_Safety_Information >> >> Vinay >> -- >> Vinay Gupta >> >> >> >> Free Science and Engineering in the Global Public Interest >> >> >> http://bit.ly/gupta_arc - the Gupta State Failure Management Archive >> http://bit.ly/gupta_ark - or see it directly on Archive.org >> >> >> >> >> >> http://hexayurt.com - free/open next generation human sheltering >> http://hexayurt.com/plan - the whole systems, big picture vision >> >> >> >> >> >> "In the midst of winter, I finally learned that there was in me an >> invincible summer" - Albert Camus >> >> Twitter/Skype/Gizmo/Gtalk/AIM: hexayurt >> UK Cell : +44 (0) 7500 895568 / USA VOIP (+1) 775-743-1851 >> >> >> >> >> >> >> -- >> >> You received this message because you are subscribed to the Google >> Groups "hexayurt" group. >> >> To unsubscribe from this group and stop receiving emails from it, >> send an email to hexayurt+unsubscr...@googlegroups.com. >> >> To post to this group, send email to hexayurt@googlegroups.com. >> >> Visit this group at http://groups.google.com/group/hexayurt. >> >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> >> >> >> >> -- >> >> You received this message because you are subscribed to the Google >> Groups "hexayurt" group. >> >> To unsubscribe from this group and stop receiving emails from it, >> send an email to hexayurt+unsubscr...@googlegroups.com. >> >> To post to this group, send email to hexayurt@googlegroups.com. >> >> Visit this group at http://groups.google.com/group/hexayurt. >> >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> >> >> >> -- >> >> You received this message because you are subscribed to the Google >> Groups "hexayurt" group. >> >> To unsubscribe from this group and stop receiving emails from it, >> send an email to hexayurt+unsubscr...@googlegroups.com. >> >> To post to this group, send email to hexayurt@googlegroups.com. >> >> Visit this group at http://groups.google.com/group/hexayurt. >> >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> framed >> hexayurts<http://groups.google.com/group/hexayurt/t/2535008f8316a1af> >> >> dylan toymaker <dylan.toyma...@gmail.com> Feb 04 09:09AM -0800 >> >> For anyone who wants to use stick framing techniques for hexayurts, >> i found a set of metal brackets to make it way easier. >> >> http://www.strongtie.com/products/DIY/GT2-GT6-GTF.html# >> >> scroll down to see the full system gallery. >> >> >> Dylan >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "hexayurt" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to hexayurt+unsubscr...@googlegroups.com. >> To post to this group, send email to hexayurt@googlegroups.com. >> Visit this group at http://groups.google.com/group/hexayurt. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- > You received this message because you are subscribed to the Google Groups > "hexayurt" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to hexayurt+unsubscr...@googlegroups.com. > To post to this group, send email to hexayurt@googlegroups.com. > Visit this group at http://groups.google.com/group/hexayurt. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To unsubscribe from this group and stop receiving emails from it, send an email to hexayurt+unsubscr...@googlegroups.com. To post to this group, send email to hexayurt@googlegroups.com. Visit this group at http://groups.google.com/group/hexayurt. For more options, visit https://groups.google.com/groups/opt_out.
