[GSBN] SB Fire Fighting Article

[martin hammer]

G Πday John,

In the article it says - ³The owner . . .said he was soldering in that area
and that there was fire in the wall under the sink.²

So I believe it started from a soldering torch, but I don¹t know what first
ignited (cabinet, drywall paper, straw, wood furring, . .).  My best guess
is that regardless of what ignited initially, the fire was quickly inside
one of the furred-out cavities between the drywall and the bales, and then
shot up to the roof framing where the fire spread and caused the most
damage.

The article does suggest the reason for the cavities (foolish, of course),
which is the owner wanted a smooth, straight drywall finish on the interior,
and installing wood furring strips on the bales to provide attachment for
the drywall seemed sensible.  They didn¹t realize they were creating a fire
hazard.  They of course could have achieved a smooth, straight plaster
finish but they might not have thought this was possible (or was too
expensive).  All of us would consider drywall over straw bale a kind of
blasphemy, but that¹s what they chose to do.

And yes, the observation you mentioned is a flawed one (among others).  My
comment (rebuttal) that I sent to Don Fisher is shown in blue in your e-mail
below.

Thanks.

Martin


On 5/3/09 4:32 PM, "John Glassford" <jacksflat at gmail.com> wrote:

> G ' day Martin
> 
> Thanks for that article most interesting and informative.
> 
> The article does not say how the fire started in the first place any clues?
> 
> Reading this article it appears that the fire may have started in the roof or
> at the kitchen sink and travelled into the roof?  Also I do not understand why
> any builder would create a straw bale wall that has cavities, makes no sense.
>  See an extract below from the article:
> 
> "The results of the recon with the thermal imaging camera {TIC} indicated that
> fire was in approximately 75 percent of the attic and that fire was traveling
> downward through the straw-filled walls in about 50 percent of the house. It
> was later determined that the top of the walls had no drywall on the top plate
> and that there was a space between the straw and the inside and outside wall.
> This flaw in construction contributed to the total loss of the building.
> 
> Because of the high winds and the exposed OSB roof decking, the
> 5,000-square-foot building¹s attic was almost totally involved. This caused
> the top of the unprotected straw bales to ignite from embers and burning
> materials that fell into the void between the bales and the interior and
> exterior walls. You could see fire with the TIC on the outside walls on the
> top of the bales and on the bottom of the bales; there was no fire in the
> middle of the wall."
> 
> Not sure about the following observations:
> 
> "The problem is that straw, like the blown treated paper insulation, is
> combustible. Both will burn when temperatures reach 1,200°F.
> (I think this unfairly targets straw bale, because in addition to the fact
> that (as you say) straw and blown treated paper insulation will burn when
> temperatures reach 1200 F, so will wood, and other wood products like plywood
> (correct me if I¹m wrong about this).  And actually, straw bale (when plaster
> is directly applied to it) is less prone to combustion than wood frame
> because there is less air and fewer or no chimney spaces to facilitate
> combustion.) To combat this, the straw stacks were designed to be treated with
> fire retardant and covered airtight with an exterior covering. In this case, a
> modification was made for aesthetic reasons."  (The bales may have been
> treated with a fire retardant in this case (borate?), but we generally do not
> considered it necessary. The airtight exterior covering generally IS
> considered necessary, and I¹m glad you pointed out this very important design
> (or construction) flaw in the AZ building.)
> 
> Thanks again Martin.
> 
> Kind regards
> The Straw Wolf
> Huff 'n' Puff Constructions

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