“i think it pretty much survived on its own, with some ... · while architects and builders have...
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Whilearchitectsandbuildershaveknownforyearsthatthestrawbalewallsoftheirbuildingshavesuperiorfire-resistance,severalexamplesofhomessurvivingrecentwildfiresbearfurtherevidenceofthisquality.Thisnewsletterdescribesandillustratesanumberofcasestudies.Alloftheseexampleswerewithintheperimeterofthewildfires,andinsomeinstancesthesestructuressurvivedwhenallelsearoundthemburned.Acombinationoffactorsaidedintheirsurvival;allhavemetalortileroofs,otherfire-resistantmaterialsanddetails,andmosthaddefensiblespace.Incertainfirestormsnostructurewillsurvive,sosomeamountofgoodfortunemustbecreditedaswell.CaseStudy#1:Sonoma
ThisstrawbalehomethatsurvivedislocatedneartheendofNorrbomRoad,northoftheCityofSonoma.TheresidencefeaturesstrawbalewallscoatedinNaturalHydraulicLimeplaster,rustedmetalroofsandaconcreteterraceadjacentthewoodframewalls.Whilethefiresburneduptotheplasteredbalewalls,andcharredaslidingwooddoor,thehomedidnotcatchfire.Theownerstated,
“Ithinkitprettymuchsurvivedonitsown,withsomepatrolsforhotspots.[It]lookslikeoncepowerisrestoredalloursystemsarego.WeareSOLUCKY!GoStrawbaleconstruction!”
MichelCouvreuxofTransMineral,purveyorsoftheNaturalHydraulicLimeusedtoplasterthewallsofthehome,notedthatthepinkhueistheresultoftheheatofthefiresdrawingoutironoxidesfromthemineralimpuritiesinthelimemix,andthattheyuseheattocreatesomeofthecolors.Headdedthatthewallssufferednopermanentdamageandshouldbeserviceablewellintothefuture.MichelprovidedCASBAwiththesephotosofthehomeafterthefire.CaseStudy#2:LovallValley
EngineerGaryBlackofIntegratedStructuresInc.providedthisaccountofastrawbalehometheirfirmdesignedandbuiltintheLovallValley,whichsurvivedthePartrickFirebetweenSonomaandNapa:
“IamveryhappytoreportthatIspokewiththeowneroftheNapahouseasthefirewasapproaching,(hegotoutintimeandcalledmebackafewdayslater).Apparentlyhalfof[the]landscapingwasdestroyedandthefireburnedforquitesometimewiththeflameshittingthewallsandeaveofthehouse.Hehadseveraloaktreesthatwereindirectcontactwiththewalls,resultinginNOdefensiblespace.Hereportsnodamagetothehouse,notevenabrokenwindowwheretheflamesclearlyburnedforsometime.RayColebelievesthatthe14”insetprotectedtheglassastheflamestendtogoverticallyoncetheyhitawall.Histwonearestneighbor’shousesburnedtotheground.”
CaseStudy#3:RedwoodValley
CASBADirectorDavidArkinreceivedthisharrowingtaleofsurvivalfromEdwardDoody,homeownerofoneofArkinTiltArchitects’strawbaledesigns:
“SpikeandIwereupinRedwoodValleyovertheweekendandhadgonetobedSundaynightabout10o’clock.Around2:30amforsomeunknownreasonIawoketofindastrangeglowoutsidemybedroomwindows.Igotupandputonmyglassesandsawthatthehousewasliterallysurroundedbyfire.Firewaseverywhere,nearandfar.Thegrassesaroundthehousewereglowingasalineofflamewastravelingacrossthelandscape.Theskywasredandlivesparkswereflyingeverywhere.Thetreesjustdownthehillfromthehousewereablaze,fueledbytheragingconflagrationoftheopen,metalstoragecontainerthathousedmysolarpowersystem,storageandmostofmytools.Treesandbrushatallpointsofthecompasswereablaze.Thefiresilluminatedisolatedpatchesoftheneardistance.Thelightwaseerieglowandallofthiswasagainstalargerbackgroundofdarkness.Afterrunningthroughthehouse,checkingoutthewindowsandfightingwavesofpanic,Ikindofjustsettledintosurvivalmodeandstartedtomovewithpurpose.Thehouseitselfdidnotappeartobeonfire,althoughitseemedlikeitwasonlyamatteroftime.Thetreesnexttothecontainerwerenowablazeandtheflamesfromthemwereawfullycloseandseemedtobelickingattheendofthehouse.Iquicklydressedandfoundmyphone,buttherewasnoservice.FlightmodesettledinandIdecidedtomakearunforit,downtheroadamiletothevalleyfloor.IhadtocoaxSpikeoutthedoorandintothefirestorm.Hewasnotanxioustoleavetherelativecalmandsafetyofthehousetorunahundredfeetacrosstheburningandburntlawnareatothetruck.Wejumpedinonlytofindthatthekeyswerebackinside.Idashedbackinside,foundthemandranbacktothetruck.Thewindowshadbeenleftopenandsparkswereinthecab,butitfiredrightupandawaywewent.Reachingthetopofmydriveway,Istoppedto
try911again.ThistimeIgotasignalandspokewithdispatch,onlytolearnthattheywereoverwhelmedwithcallsfromalloverthecountyandalreadyinfulloutresponse.Therewouldnotbeanyoneavailabletocometomyimmediateassistance.Itriedtocallmyuphillneighbor,butgotnoanswer.ThereIwas,poisedatthemouthofmydrivewaywiththefireadvancingupthehillsidebehindme,theravinesoneithersideofthepropertyalightwiththeunderbrushandtreesonfireandthewoodsatthetopofthepropertystartingtogo.Totherightwastheroaddowntothevalleyfloor.FormostofwhatIcouldsee,thewaywasopenwithonlywhatappearedtobesmallblazes,alongtheroadside.Totheleftwasthedriveuptomyneighbor’shouse,awindingroadthatwentthroughthewoodsthatwasnowstartingtocatchonfire.Iwasfacedwiththedecisionoffleeingdownhillorgoinguphilltoseeifmyneighborwashome,awakeandabletogetout.Ihaveneverbeensoscaredinmylife.
AsIsoughtthestrengthtogouphill,headlightspiercedthesmokeandRonnie’scarcamearoundthebend.Ihaveneverbeensorelievedinmylife.Whileweconferredandweredecidingonwhattodo,thewellhouse,downtheroundaboutaneighthofamileeruptedintoflames,blockingourpassagethroughforimmediatefuture.Forthoseofyouthathavenotyetvisited,myhousesitsinaclearingonthesideofahill.Theclearingisapproximatelythreetofouracreswithonlygrassesandlowvegetation,afewlargeoaksandawayfrommostoftheoverhangingtrees,whichlinetheperimeter.Thegroundfireswerebeingdrivenuphillbyagale-likewindandwerewellpastthehouseandthroughmostoftheclearingbynow,sowewererelativelysecureoutthereintheopen.Theairwasfulloflightedembers,peltinguslikeraindrops.Smokeandashwereswirlingthroughtheskyandbreathingwasabitdifficult.Asthecontainerfireburnedthroughthecontents,thetreesnexttoitweremostlyburntout.Thehouseappearedtonolongerbeinimminentdanger,soweretreatedthereandsettledintowaitouttheremainderofthestorm.”
Theowner,whohaskindlyagreedtomaketheplansofhishomeavailabletootherfirevictims,providedthephotos.ArkinTiltisprovidingthisandeightotherstrawbaleplansetsfreeofcharge,includingengineeringcourtesyofATA’sofficepartnersVerdantStructuralEngineers.
CaseStudy#4:Napa
Aremoteone-roomstudiowithstrawbalewallsonthreeofitsfoursidesburnedintheAtlasFireontheeastsideofNapathefirstnightofthewildfires,whenwindswereoutofthenortheastandgustingtoover70mph.Theeastendofthestructurefeaturedwoodframingtotheground,withatrellisabove;oncetheseignitedtherestofthestructurewasconsumed.Theownerreportedthefollowing:
“Itlookstomethattheplastercoatedstrawbalesurvivedwelluntilthewoodpartofthestructureburneddown.Iwonderifthewallswouldstillbeintactiftheplastercoatinghadcoveredthetopofthewallaswell.Ithinkthestrawburnedafterthetopcapofthewallburnedawayandcoal/embersdroppedintothestrawbales.Tomethestrawbaleencapsulatedintheplaster/concretestoodupwelluntilthetopwasgone.”
DavidArkinvisitedthewallsonDecember2,2017,justpriortodemolition,andobservedthatthePISE(pneumaticallyimpactedstabilizedearth)wallswerestillstanding,andhadbeenwellbondedtothestrawpriortothefire.Twospecificassembliesofstrawbalewallshavebeentested,andonewithalime-cementplasteroverbalesplacedon-edgeachievedatwohourfireratinginanASTME119test.Additionally,balesasinsulationhavearewithincodelimitsfortheflamespreadindexandsmokedevelopedindex,confirmedinanASTM-E84test.Linkstothetestreportsareprovidedbelow.Inadditiontofire-resistivequalities,strawbalewallssequestercarbonintheirconstruction,andthroughouttheirlife—alongwiththoughtfulpassivedesignandotherdetails—helptokeepstructurescoolerinsummerandwarmthroughthewinter.Learnmoreatwww.strawbuilding.orgForfurtherinquiriescontactCASBADirectorDavidArkin,AIA,[email protected]:FreeDownloadofthe2015IRCStrawbaleCodewithCommentaryfromtheCASBAwebsite:http://www.strawbuilding.org/news/3587353StrawBaleFireTestVideo:https://www.youtube.com/watch?v=PjM0yXF7sy8StrawBaleTesting(firetestsandmanyothers):http://www.strawbuilding.org/testinghttp://www.ecobuildnetwork.org/projects/straw-bale-construction-supporting-documents