This document was prepared by

URS Group, Inc.200 Orchard Ridge Drive, Suite 101Gaithersburg, MD 20878

Acknowledgements

Federal Emergency Management Agency (FEMA)

L. Gina White, FEMA Region IV, Mitigation, Project Monitor

David Kennard, FEMA Region IX, Mitigation

Daniel Powell, FEMA Region IX, Mitigation

Dennis Tewksbury, FEMA Region I, Mitigation

Christopher Hudson, FEMA HQ, Mitigation

State of California

Ernylee Chamblee, California Department of Forestry and Fire Protection

Greg Griswold, California Department of Forestry and Fire Protection (San Diego Unit)

Tom O’Keefe, California Department of Forestry and Fire Protection (San Bernardino Unit)

Ken Worman, Governor’s Office of Emergency Services

Local California Officials

Cliff Hunter, Rancho Santa Fe Fire Protection District

Clay Westling, City of San Diego

Bill Metcalf, North County Fire District

Technical Assistance Contractor Team

Christopher M. Barkley, PE, URS Group, Inc., Task Order Coordinator

Diana Burke, ELS, URS Group, Inc.

Sherry Crouch, PE, URS Group, Inc.

Michael Gayrard, URS Group, Inc.

Rich Schell, RPF #1978, RWS Consulting

Thomas L. Smith, AIA, TLSmith Consulting, Inc.

Chris White, Anchor Point Group

Cover photo: Anchor Point Group, Boulder, CO

FS No. 1 – Wildland/Urban Interface Construction HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of5

Wildland/Urban Interface Construction Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 1

Purpose Toprovideinformationaboutwildfirebehaviorandrecommendationsforbuildingdesignandconstructionmethodsinthewildland/urbaninterface.Implementationoftherecommendeddesignandconstructionmethodscangreatlyincreasethechancesofabuilding’ssurvivalinawildfire(seeFigure1).

BackgroundWildfiresareacommon,natural,andessentialoccurrenceintheforests,woodlands,brushlands,andgrasslandsoftheUnitedStates.Whenconditionsareacceptable,fireprofessionalsusefiretorevitalizetheecosystemandreduceaccumulatedvegetationthatcanfuelawildfireundercertainconditions.

Althoughtheseverityandtimingoffireseasonsvarywidelyfromregiontoregion,wildfiresoftenposeathreattolives,property,andresources.Duringanaveragefireseason,hundredsofhomesaredamagedordestroyedbywildfire,andinextremefireconditions,thousandsofhomescanbedamagedordestroyed.Severefireweatherinareaswithsignificantamountsofwildlandfuelscanleadtoextremefirebehavior.

WildlandfuelsvarythroughouttheUnitedStates.InthePacificnorthwestandtheLakeStates,forestsarethepredominatewildlandfuel.InsouthernCalifornia,chaparralbrushpredominates.Theplainsstateshavegrassandoakwoodlands,NewJerseyhasPineBarrens,andthesoutheasthaspineandhardwoodforests.

Figure 1. Ahomeinthewildland/urbaninterfacethatsurvivedawildfire(AnchorPointGroup,Boulder,CO).

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Wildfirescandamagebuildingsthroughdirectflamecontact,convection(heatthatrisesfromafireandcreatesasmokecolumn),conduction(heatthattransfersthroughmaterialsuchasmetalroofsandrailings),andradiation(heatfromafirenexttothebuilding).Wildfirescanalsocreateburningembersthatriseinthesmokecolumnandfallonbuildings.Firebrands(largepiecesofwind-driven,burningmaterial)canbeblownthroughwindowsorlodgedagainstabuildingandleadtoignitionofthebuilding.

Traditionaleffortstoprotectbuildingsfromwildfireshavefocusedonfightingthefirebeforeitreachesthebuildings.Withtheexpansionofresidentialconstructionintopreviouslyundevelopedforestsandwildlands,morebuildingsarenowatriskfromwildfires.Fightingorsuppressingthefireisoftendifficultorimpractical;buildingsmustthereforealsobeconstructedtobefire-resistant.Nobuildingcanbecompletelyfireproof,butimplementingtherecommendationsthataredescribedintheseFactSheetsshouldgreatlyreducethepotentialfordamagetoabuildingandgreatlyincreaseitschanceofsurvival.

Construction in the Wildland/Urban InterfaceThefollowingfactorsaffecttheprobabilitythatabuildingwillsurviveawildfire:Topographyandweather•Defensiblespace•Buildingenvelope•Communityinfrastructure•

Topography and WeatherWildfiresgenerallyfolloworaredrivenbyterrainandweather.Buildingsatthetopofacanyonorridgeline,atmid-slope,orinaravinehaveahigherriskfordamagefromawildfireduetotheinteractionofthesefeatureswithstrongwindsthanatlocationssuchasvalleybottoms.Whenaconstructionsiteisselected,thetopographicfeaturesonandsurroundingasiteshouldbeevaluatedfortheirpotentialcontributiontotheexposureofabuildingtoawildfire.Abuilding’sconfigurationandlocationonasiteshouldbepredicatedonminimizingtheriskfromthesetopographicfeatures.

SeeFactSheet#3,SelectingtheConstructionSite.

Defensible Space Wildfirestravelquicklyinareaswherevegetationisdryandabundant.Adefensiblespacearoundabuildingcanimprovetheprobabilitythatthebuildingwillsurviveawildfire.Adefensiblespaceisanareawherecombustiblematerial,includingvegetation,hasbeentreated,clearedormodifiedtoslowtherateandintensityofanadvancingwildfireandtocreateasaferareaforfire-suppressionoperationstooccur.Buildingssurroundedbyzonesofnon-vegetatedareasorareaspopulatedbyfire-resistantvegetationaremorelikelytosurvive.

SeeFactSheet#4,DefensibleSpace.

FS No. 1 – Wildland/Urban Interface Construction HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of5

Building Envelope Duringawildfire,combustibleexteriorbuildingcomponentssuchasroofcoverings,siding,anddeckscanignite,leadingtoseveredamagetoortotallossofthebuilding.Therefore,theuseofnoncombustibleorfire-resistantmaterialsshouldbeconsideredforexteriorcomponents.Figure2showsthecomponentsofthebuildingenvelope.

Alsocriticalistheconfigurationofthenoncombustibleorfire-resistantmaterials.Unlessconstructionmeasuresthatprovideprotectionfromawildfireareimplemented,heatandemberscanpenetratethebuildingenvelopeatvents,unsealedmechanicalorelectricalopenings,andthroughwindowsbrokenbyheatorwind-blownfirebrands.Whentheseopeningsarepenetrated,thebuildingcanburnfromtheinsideout.

Iftheenvelopehasbeendesignedandconstructedtobefire-resistant,boththeexteriorandinteriorofthebuildingwillbemorecapableofresistingawildfirelongenoughforthedangertopassorforfirefighterstoarrive.

SeeFactSheets#5through#16.

Community InfrastructureAhomethathasbeenconstructedtobefire-resistantandhasadefensiblespacemaynotbesufficienttopreventdamagefromawildfire.Survivingawildfiremayalsodependoninfrastructuresuchaslocalwaterresourcesforfirefightingandroadsthataredesignedforemergencyvehicleaccess.Thebuildingsiteshouldalsohaveadequateinfrastructuretoensureaccessforfirefightingcrews.

SeeFactSheet#17,CommunityInfrastructure.

Figure 2. Thebuildingenvelope.

Building Envelope

Vents

Garage door Exterior door

Siding

Roof Deck

Fence

Windows

Eaves

Foundation

Gutters

Page4of5 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 1 – Wildland/Urban Interface Construction

Prioritizing Fire-resistant Construction TechniquesTheriskofwildfirevariesgreatlyanddependsonlocalfuels,weather,andtopography.Theriskatabuildingsitemustbedeterminedbeforetheappropriatedesignandconstructionmethodsforaneworexistingbuildingcanbeselectedandthemeasurescanbeprioritized.

Hazard and Risk AssessmentsThefoundationofanaccuratehazardandriskassessmentisinformationonwildfirefuels,weather,topography,assetsatrisk,andtheprobabilityofawildfireoccurrence.Asitecanbeinanareawithaveryhighhazard(highlyvulnerabletowildfire)buthavealowriskofwildfire,suchasasiteatahighaltitude.ThisinformationcanbeusedtodesignateFireSeverityZones.Thezonescanthenbegivenarating,fromlowtoextreme,asshowninFigure3.

Ahazardandriskassessmentcanhelpdeterminethelevelofmitigationthatisneededforabuilding.Theassessment,whichcanbeconductedataregional,state,orlocallevel,needstobebothcredibleandprofessionaltoensurethattheanalysisisaccurate,comprehensive,andverifiable.Someregional,state,andlocalagenciesproducehazardriskmapssimilartothoseshowninFigures3and4.Thesemapsmaybefoundinstate,tribal,andlocalagencyhazardmitigationplansthathavebeenapprovedbytheFederalEmergencyManagementAgency(FEMA).

New BuildingsFornewconstruction,FEMArecommendsfollowingthedesignandconstructionguidanceprovidedinthisseriesofFactSheets.

Existing BuildingsFEMArecognizesthatitmaynotbefinanciallypossibleforthehomeownertoimplementallofthemeasuresthatarerecommendedinthisseriesofFactSheets.FEMArecommendsthathomeownersconsultwithlocalfireandbuildingcodeofficialsorotherfiremanagementspecialiststoperformavulnerabilityassessmentanddevelopacustomized,prioritizedlistofrecommendationsforremedialworkondefensiblespaceandthebuildingenvelope.

Helpfulinformationaboutthevulnerabilitiesofthebuildingenvelopeisavailableathttp://firecenter.berkeley.edu/default.htm.TheHomeowner’sWildfireAssessmentsurveyonthis

Figure 3. Exampleofafirehazardratingmap.Firehazardratingscanhelpdeterminethelevelofmitigationthatisnecessaryforwildfiremanagement(AnchorPointGroup,Boulder,CO).

FS No. 1 – Wildland/Urban Interface Construction HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page5of5

websiteisahelpfultoolthatpropertyownerscanusetolearnaboutthespecificrisksaparticularbuildinghasandthemeasuresthatcanbetakentoaddressthem.

Construction StandardsManycommunitiesenforceregulationsregardingwhereandhowbuildingsmaybesited,designed,andconstructed.Theregulations,however,refertominimumstandards.Individualpropertyownershavetheoptiontoexceedthesestandards,anddoingsoveryoftenincreasestheprobabilitythatthehomewillsurviveawildfire.

ResourcesCenterforFireResearchandOutreach.UniversityofCalifornia,Berkeley:CollegeofNatural

Resources.http://firecenter.berkeley.edu/default.htm.

Christman,L.2008.Trial by Fire: Can Your Home Take the Heat? Redding.com:Home&Garden.http://www.redding.com/news/2008/Feb/16/trial-fire-can-your-home-take-heat/.

Underwood,J.1995.“Fire-ResistantDetails.”Fine Homebuilding96:90–93.http://www.taunton.com/finehomebuilding/how-to/articles/fire-resistant-details.aspx.

Figure 4. Exampleofafuelmodelmap.Fuelmodelsthatdemonstratethelocationofcombustiblevegetationarepartofthefoundationforfirebehaviorcalculations(AnchorPointGroup,Boulder,CO).

FS No. 2 – Summary of Recommendations HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of5

Summary of Wildfire Construction Recommendations Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 2

Stateandlocalcodesshouldincluderequirementsforwildfiremitigationforbothnewconstructionandupgradestoexistingbuildingsinwildfirezones.Inareaswherebuildingsareparticularlyvulnerabletotheriskofwildfire,implementingmeasuresthatexceedthecodescanimprovetheprobabilitythatabuildingwillsurviveawildfire.

TheUnified Hazard Mitigation Assistance GuidanceandtheWildfire Mitigation PolicyfortheHazardMitigationGrantProgram(HMGP)andPre-DisasterMitigation(PDM)ProgramprovideinformationonwhichactivitiesareconsideredeligibleforfundingbytheFederalEmergencyManagementAgency(FEMA)forwildfiremitigationactivities.

ThisseriesofTechnicalFactSheetsfromFEMAprovideinformationabouthowtominimizethepotentialfordamagetoordestructionofbuildingsinwildfirezonesfromwildfires.Theinformationpertainstobothnewandexistingbuildings.

TheFactSheetsareavailableontheFEMAwebsite(www.fema.gov)asAdobePortableDocumentFormat(PDF)files.YoumusthaveAdobeReadertoviewthePDFfiles.ThelatestversionofAdobeReaderisrecommendedandcanbedownloadedfromwww.adobe.com.

ThefollowingisasummaryoftherecommendationscontainedinFactSheets#3through#17.

Fact Sheet #3: Selecting the Construction Site

Topographicfeaturessuchasslopesandcanyons,localvegetation,andweathercangreatlyinfluencewildfirebehavior.Homebuildersshouldconsiderthesefactorscarefullywhenselectingaconstructionsite

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Fact Sheet #5: Roofs

Ofthecomponentsofthebuildingenvelope,theroofisthemostvulnerableinawildfirebecauseofitssizeandorientation.Theprobabilitythatahomewillsurviveawildfireisgreatlyinfluencedbythecomponentsoftheroofassembly.ClassAratedroofassemblieswithnoncombustiblecoveringsarerecommended.

Fact Sheet #6: Eaves, Overhangs, and Soffits

Windborneembersandconvectiveandradiantheatcanbetrappedneareavesandsoffits,whichcanigniteifnotconstructedofnoncombustibleorfire-resistantmaterials.Eaveswithshortoverhangsandflatsoffitswithaminimumofa1-hourfire-resistanceratingarerecommended.

Fact Sheet #7: Exterior Walls

Howwellexteriorwallsareabletoresistawildfiredependslargelyonthematerialsusedtoconstructthewall.Exteriorwallcoveringsthatarenoncombustibleorfire-resistantandnotsusceptibletomeltingarerecommended.Aminimumfire-resistanceratingof1hourforthewallassemblyisrecommended

Fact Sheet #4: Defensible Space

Creatingadefensiblespace,whichcanoftenbedonebythehomeowner,isrecommended.Adefensiblespaceisanareaaroundahomeinwhichvegetation,debris,andothertypesofcombustiblefuelshavebeentreated,cleared,orreduced.Landscapemanagementcreatesabarrierbetweenahomeandawildfire.Withoutadefensiblespace,firefightersmaynotattempttoprotectthehomebecausedoingsowouldbetoohazardous.

FS No. 2 – Summary of Recommendations HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of5

Fact Sheet #9: Gutters and Downspouts

Combustibledebrissuchasleavesandpineneedlescanbecometrappedingutters.Thedebriscanbeignitedbyflyingembersorfirebrandsduringawildfire,andthefirecanspreadtotheroof.Noncombustibleleafguardsoverguttersandguttersconstructedofnoncombustiblematerialsarerecommended.

Fact Sheet #10: Windows and Skylights

Flames,firebrands,radiantheat,andfailedframescancauseglazingtobreakorotherwisefail.Glazing(glass,plastic,ortranslucentmaterial)thatfailsallowseasypassageofembersandhotgasesintotheinteriorofabuilding.Insulatedglazingunitsarerecommended.Thefireratingofwindowassembliesshouldbecommensuratewiththefireratingofthewall.

Fact Sheet #11: Exterior Doors

Combustibledoorsandframescanbeignitedinawildfire,andopeningsbetweenthedoorandframeandglassinthedoorcanbepenetratedbyflames,hotgases,orembers.Thefireratingofthedoorshouldbecommensuratewiththefireratingofthewall.Weatherstrippingandnoncombustibleorfire-resistanttrimarerecommended.

Fact Sheet #8: Vents

Embersandhotgasescanbeblownorpulledintoventopeningsandenteratticspaces,crawlspaces,andductwork,leadingtoignitionoftheinteriorofthebuilding.Ventsthatareaminimumof10feetfrompropertylinesandotherbuildings,constructedofmetalproducts,andhavecorrosive-resistantmetalmeshscreensarerecommended.

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Fact Sheet #14: Landscape Fences and Walls

Onceignited,afenceconstructedofcombustiblematerialsthatisattachedtoornearabuildingcanignitethebuilding.Fencesandwallsconstructedofnoncombustiblematerialssuchasconcrete,stone,andmasonryarerecommended.Attachingafenceorwalltothebuildingshouldbeavoidedunlessthefenceorwallisconstructedofnoncombustiblematerials

Fact Sheet #15: Fire Sprinklers

Theinteriorofabuildingcanignitefromawildfireevenwhentheexteriordoesnot.Interiorandexteriorfiresprinklerscanpreventsubstantialdamagetothebuilding,protectnearbybuildings,andpreventthefirefromignitingnearbycombustiblevegetation.

Fact Sheet #13: Decks and Other Attached Structures

Embers,firebrands,andhotgasescanbecometrappedunderdecksandotherattachedstructures.Decksconstructedofheavytimberornoncombustiblematerialsarerecommended.Isolatingtheattachedstructurebysurroundingitwithnoncombustiblematerialsuchasgravel,brick,andconcretepavers,andenclosingtheundersideofthedeckwithfire-resistantskirtingarealsorecommended.

Fact Sheet #12: Foundations

Embers,firebrands,andhotgasescanignitecombustiblefoundationwallsandpenetratecrawlspaceventsandbreachedbasementwindows.Walls,vents,andwindowsinclosedfoundationsshouldbeconstructedinaccordancewiththeguidanceintheseFactSheets.Inhomeswithopenfoundations,protectingtheundersideofthefloorstructurewithfire-resistantmaterialsisrecommended.

FS No. 2 – Summary of Recommendations HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page5of5

Fact Sheet #17: Community Infrastructure

Accessroadsanddrivewaysthatarewideandstrongenoughtoaccommodateemergencyvehiclesandprovideaccessforfirefightingeffortsarenecessary.Waterresourcesforwildfiresuppressionmustbeaccessible.Roadsandwatersourcesshouldbewellmarkedonsignsconstructedoffire-resistantmaterialsforeaseofusebyemergencyresponsepersonnel.

Fact Sheet #16: Utilities and Exterior Equipment

Mostutilitiesrequirepenetrationofthebuilding’senvelopeforductingandconduit.Utilityconnectionsshouldbeinstalledunderground,ifpossible,andgapsandpenetrationsinexteriorwallsandroofsshouldbesealedwithfire-resistantproducts.Fuelshouldbestoredundergroundorsurroundedbyanoncombustiblebarrier.

FS No. 3 – Selecting the Construction Site HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of4

Selecting the Construction Site Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 3

PurposeTohelppropertyownerswhoplantobuildhomesorotherstructuresinwildfirezonesunderstandtherelationshipbetweenwildfirebehaviorandfuels,weather,andtopographysotheycanselectconstructionsitesthatminimizethepotentialfordamagefromwildfires.TheguidancelistedinthisFactSheetappliesonlytonewbuildings.

Key IssuesWildfiresspreadmorequicklyonupslopedterrainthan•onlevelterrain(seeFigure1).Topographicfeaturessuchasslopes,saddles,ridges,andcanyonscanthereforeinfluencewildfirebehavior(seebelowforadescriptionofthesefeatures).Theinteractionofwindandradiantheatwithsomeofthefeaturesisalsoanimportantfactorinwildfirebehavior.Thedirectionaslopefacesinfluencesthegrowthof•vegetation,andvegetationinfluenceswildfirebehaviorbecauseitprovidesfuelforthewildfire.Implementingthefire-mitigationmeasuresdescribedin•theotherFactSheetscannotentirelyoffsetthepotentialfordamagefromawildfireathigh-risksiteswithtopographicandvegetationfeaturesthatcancontributetoextremefirebehavior.

Topography Sloped terrain. • Wind-drivenwildfiresfollowwinddirectionandareminimallyinfluencedbytopography.Intheabsenceofastrongwind,wildfirefollowstopography,burningprimarilyupslopeandup-canyon.Wildfiresspreadupslopequicklybecauseheatrisesandpreheatsandignitesfuelssuchasbuildingsandvegetation.Saddles.• Whereavalleycrossesaridge,asaddleiscreatedbetweentwopeaks(seeFigure2).Saddlesactaswindfunnelsandareoneofthemosthazardouslocationsforhomesintermsofwildfire.

Figure 1.Firespreadsmorequicklyonupslopedterrainthanonlevelterrain.

Fuel,topography,andweatherarethethreeprincipalenvironmentalelementsthataffectwildfirebehavior.Fuels(vegetation)andlocaltopographyshouldbeconsideredwhenchoosingasiteforahometoincreasethechancethehomewillsurviveawildfire.

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Ridgetops and hilltops.• Wind speeds on ridgetopsandhilltopscanbeunpredictablebuttendtobehigherthanthoseinthesurroundinglowerareasbecauseofthehigherelevationandbecausewindspeedincreasesasitflowsoverabruptchangesintopography.Buildingsintheselocationscanhave360-degreedownhillexposuretowildfire.Canyons. • Awildfireatthebottomofavegetatedcanyoncanleadtoextremelyhazardousconditionsupslope.Acanyonactslikeachimney,collectinghotgasesanddirectingsuperheatedconvectionandradiantheatupslope.Canyonsfunnelwinds(seeFigure3)thatcanfanafireandleadtoextremefirebehavior(rapidspreadofthewildfireandignitionofanentirearea).Anentirecanyoncanpre-heatfromrisinghotairandgasesandexplodeinflames,creatingafirestorm.

VegetationVegetationactsasafuelforwildfires.Vegetationbothonandadjacenttoasitecanaffect•theprobabilityofdamagetoabuildingfromawildfire.Characteristicsofvegetationsuchasdensity,continuity,andtypecaninfluencewildfirebehavior(seeFactSheet#4,DefensibleSpace,formoreinformation).South-andwest-facingslopesgenerallyretainlessmoisture,producelessvegetation,and•dryoutearlierintheyearthannorth-andeast-facingslopes.Firesondryerslopestendtoignitemoreeasily,travelmorerapidly,andburnoutfasteraslightfuelsareconsumed.Themoreheavilyvegetatedmoistslopeshavealowerpotentialforignitionbutcansustainamoreintensefireoflongerdurationthandryslopes.

Guidance Byunderstandinghowtopographyandvegetationcaninfluencewildfirebehavior,propertyownerscanselectconstructionsitesinwildfirezonesthatreducethepotentialfordamagetoabuildingfromawildfire.Followingtheguidancelistedbelowcanincreasetheprobabilitythatabuildingwillsurviveawildfire.Avoidselectingaconstructionsitealongagullyorinanarrowcanyon.•Avoidselectingaconstructionsiteinoradjacenttoasaddleornarrowmountainpass.•Avoidconstructingahomeadjacenttooronasteepslope.Ifaridgetopsiteisselected,choose•

Figure 2. Windbehavioroverasaddle.

Figure 3.Windbehaviorthroughacanyon.

FS No. 3 – Selecting the Construction Site HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of4

anareathatallowsforaminimum50-footsetbackfromwildlandvegetationonthedownslopeside(seeFigure4).Increasethesetbackatsiteswithheavierfuelssuchasinaforestedenvironment.ImplementthemeasuresinFactSheet#4,DefensibleSpace;FactSheet#12,Foundations;andFactSheet#13,Decks.Orientthenarrowestwallofthe•buildingtowardthelikelypathofawildfiretominimizetheriskofstructuralignition.Orientthebuildingbasedonwindandfuelssothatdebris,embers,andfirebrandsdonotaccumulatenexttothebuilding’swalls,especiallyneartheinsidecornersofentriesandotheroff-setwalls.Minimizethenumberofwindowsonthesideofthebuildingfacingthelikelypathofawildfire•toreducetheriskofradiantheatorfirebrandsandflyingdebrisbreakingthewindows,allowingthefiretoenterthebuilding.

ConsiderationsConsiderthevegetationcharacteristicsonandadjacenttothesiteincludingdensity,continuity,•andtype.Ifthesitehasheavy,continuousvegetation,avegetationmanagementplanmaybeneededtoreducethehazard.Creatingadefensiblespacecanenhancefireresistance(seeFactSheet#4,DefensibleSpace).Consideraccesstothehome.Steepdrivewaysandnarrowroadscanlimitaccessibilitybyfire-•fightingequipment(seeFactSheet#17,CommunityInfrastructure).Evaluatethevulnerabilitytofireofneighboringproperties.Iftheneighboringpropertieshave•firehazardsbuttheneighborsareunwillingtocooperateindevelopingamutualdefensiblespace,considerthatinformationinselectingfire-resistancemeasuresforthebuilding.

EffectivenessTheeffectivenessoftherecommendedmeasurescanvarysignificantly,dependingontheinteractionoffuels,weather,topography,andwildfirebehavior.

ResourcesBarkley,Y.C.,C.Schnepf,andJ.Cohen.2005.Protecting and Landscaping Homes in the

Wildland/Urban Interface.StationBulletin#67.Moscow,Idaho:IdahoForest,WildlifeandRangeExperimentStation.www.treesearch.fs.fed.us/pubs/22257.

CaliforniaDepartmentofForestryandFireProtection.www.fire.ca.gov.

CaliforniaFireSafeCouncil.www.firesafecouncil.org.

Figure 4.Exampleofsetbackfromwildlandvegetation.

50 feet

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FirewiseCommunitiesProgram.www.firewise.org/newsroom/faq.htm.

NationalWildfireCoordinatingGroup.www.nwcg.gov.

Slack,P.2000.Firewise Construction Design and Materials.ColoradoStateForestService.

FS No. 4 – Defensible Space HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of4

Defensible Space Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 4

PurposeToprovideinformationaboutcreatingadefensiblespacetoreducethepotentialfordamagetohomesfromwildfires.Guidancepertainstobothnewandexistingbuildings.

BackgroundAdefensiblespaceisanareaaroundabuildinginwhichvegetation,debris,andothertypesofcombustiblefuelshavebeentreated,cleared,orreducedtoslowthespreadoffiretoandfromthebuilding.Informationaboutlocalvegetation,weather,andtopographyisusedtodeterminetheFireSeverityZoneofanarea,whichcanhelpdeterminethemosteffectivedesignofadefensiblespace.

Adefensiblespaceisoneofthemostcost-effectivewaystoprotectabuildingfromawildfireandcanoftenbecreatedbythepropertyowner.

Key Issues Wildlandvegetationsuchasgrass,brush,andtimbercanbeextremelycombustible.The•vegetationcanburnwithgreatintensityandproducefirebrandsandburningembersthatcanbecomewind-drivenhazards.Landscapevegetationcanbeascombustibleaswildlandvegetation.•Combustibleplantshavethesecharacteristics:•

Volatileresinsandoils(generallyaromatic –whencrushed)

Narrowleavesorlong,thinneedlessuchas –coniferneedles

Waxyorfuzzyleaves –

Anaccumulationofdeadleavesandtwigson –andundertheplant

Looseorpaperybark –

Awildfirecanmovehorizontallyfromshrubto•shrubandtreetotree.Awildfirecanalsotravelverticallyfromthegroundupintothetreetops,resultingina•catastrophiccrownfire(afirethatcantravelatanincrediblepacethroughthetopofaforest).Figure1showsafirethatisspreadingverticallyfromgrassestoshrubstolowbranches.Accessorybuildingsandstructuresandotheritemscommonlyfoundinyardsthataremade•

Figure 1.Firespreadsverticallythroughvegetation(AnchorPointGroup,Boulder,CO).

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ofcombustiblematerialscanalsoputanotherwisefire-resistantbuildingatriskofignitionanddestruction.Combustiblevegetationandmaterialsarounda•building(seeFigure2)can:

– Increasetheriskofbuildingignition

Restrictthespacenecessarytoprovide –firefightersarelativelysafeplacetoprotectabuilding

Increasethechancethatabuildingonfire –willigniteadjacentwildlands

GuidanceAssessboththehorizontalandverticalaspectsofvegetationwhendesigningthedefensible•space.Topreventthehorizontalspreadofwildfire,thinshrubsandtreessothecrownsdonot•intersectandthereisspacebetweenindividualshrubsandtrees.Topreventtheverticalspreadofwildfire,keepthelowesttreebranchesprunedandtrimmed•tomaintainverticalseparationfromthetopofshrubsandgrassestothelowesttreebranches.Theverticaldistanceneededwillvarysignificantly,dependingonthespeciesoftreeandcompositionoftheunderstory.Createthreeconcentriczonesaroundthebuilding(seeFigure3).Zone1,thezoneclosest•tothebuilding,normallyhasthegreatestneedforfuelmodificationwithprogressivelylessmodificationintheothertwozones.ThehighertheFireSeverityZone,thelargertheconcentriczonesshouldbe.Consultthelocalorstatefireagencyforassistance.Thethreezonesarediscussedfurtherbelow.

Zone 1EliminateallcombustiblematerialsinZone1(within30feetofthehome)suchasfire-prone•vegetation,firewoodstacks,combustiblepatiofurniture,umbrellas,anddimensionedlumberdecking(seeFigure4).Desirablesubstitutionsincludeirrigatedgrass,rockgardens,stonepatios,metalpatiofurniture,andnoncombustibledecking(seeFactSheet#13,DecksandOtherAttachedStructures).Beforefireseasonbegins,removecombustiblelitteronroofsandguttersandtrimtree•branchesthatoverhangtheroofandchimney(seeFactSheet#9,Gutters).

Zone 2EnsurethatZone2includesonlyindividualandwell-spacedclumpsoftreesandshrubs •and/orafewislandsofvegetationthataresurroundedbyareaswithnoncombustiblematerials.

Figure 2. Combustiblematerialsadjacenttoabuildingcreateahazard(AnchorPointGroup,Boulder,CO).

FS No. 4 – Defensible Space HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of4

Usehardscapefeaturessuchasdrivewaysandpavedorgravelwalkwaysorpatiostocreate•firebreaksthroughouttheyard.Plantfire-resistant,low-volumevegetationthatretainsmoisturewellandneedsminimum•maintenancesuchaspruningandremovingdeadanddyingbranches.Separateauxiliarystructuressuchasadetachedgarage,pumphouse,pergola,andutilityshed•fromthehomebyatleast50feet.Increasethedistanceifthestructureisusedforthestorageofcombustiblematerials.Complywithrecommendedconstructionpracticesrelatedtofireresistanceforauxiliary•structures.SeeFactSheets#5to#16forguidanceonplanninganddesigningastructureinawildfirezone.Ensurethatpatiofurnitureiseithermadeof•noncombustiblematerialsuchasmetalorisatleast30feetawayfromthebuilding.Storepatiofurnitureinalocationthatisprotectedfromignitionbyawildfire.Placewoodpilesatleast30feetfromthe•buildingandstorethewoodinavegetation-freezonesuchasagraveledarea.Storefueltanksawayfromastructureatthe•minimumdistancethatisrequiredbycodeorgreater(seeFactSheet#16,Utilities)andplaceundergroundoronanoncombustiblepad.

Figure 4.AnoncombustiblegroundcoverinZone1helpedthishomesurviveawildfire(AnchorPointGroup,Boulder,CO).

Figure 3. Thethreeconcentriczonesofdefensiblespace.

Page4of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 4 – Defensible Space

Zone 3Reducefuelsthatarefartherthan100feetfromthebuildingbythinningandpruningvegetationhorizontallyandverticallyasdiscussedabove.ThinningandpruninginZone3canbemorelimitedthaninZone2.ThegoalsinZone3aretoimprovethehealthofthewildlandsandhelpslowanapproachingwildfire.Zone3isalsoanaesthetictransitionbetweenthemoreheavilymodifiedZone2andtheunmodifiedsurroundings.

ConsiderationsConsultthelocalorstatefireagencyorqualifiedfiremanagementspecialistaboutcodes,•requirements,andstandardsrelatedtodefensiblespace.Codes,requirements,andstandardsnormallyrepresenttheminimumthatshouldbedone.Considerationshouldbegiventoprovidingenhancedprotectionmeasuresbeyondtheminimumrecommendedorrequired.Maintainingadefensiblespacerequiresroutinemaintenanceofvegetation,whichincludes•pruningandremovingdeadbranchesandleaves.Characteristicsoflow-maintenanceplantsare:

Drought-resistant –

Pest-resistant –

Nativetothearea –

Noninvasive –

Slow-growing –

Wind-resistant –

Sustainablewithoutsupplementalfertilization –

Vegetationmodificationmustbeperformedincompliancewithlocal,state,andfederal•environmentalregulations.

EffectivenessAllmitigationmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZones.

ResourcesBarkley,Y.C.,C.Schnepf,andJ.Cohen.2005.Protecting and Landscaping Homes in the

Wildland/Urban Interface.StationBulletin#67.Moscow,Idaho:IdahoForest,WildlifeandRangeExperimentStation.www.treesearch.fs.fed.us/pubs/22257.

FirewiseCommunitiesProgram.www.firewise.org/newsroom/faq.htm.

NationalFireProtectionAssociation(NFPA)1144:StandardforReducingStructureIgnitionHazardsfromWildlandFire.2008.http://dnrc.mt.gov/forestry/Fire/Prevention/documents/WUIrewrite/NFPA1144.pdf.

NationalWildfireCoordinatingGroup.www.nwcg.gov.

FS No. 5 – Roofs HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of5

Roofs Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 5

PurposeToprovidegeneralguidanceonthedesignandconstructionofroofassembliesonbuildingsinwildfirezones. Guidancepertainstobothnewandexistingbuildings.

Key Issues Roofassembliesarethemostvulnerable•componentofthebuildingenvelopeinawildfirebecauseoftheirhorizontalorientationandsize.Embersandfirebrandscanignitetheroof•covering,otherroofcomponents,anddebrisontheroof.Oncetheroofhasignited,thefirecommonlypropagatesintotheinteriorofthebuilding,resultinginsubstantialdamagetoortotallossofthebuilding.Theprobabilitythatahomewillsurviveawildfireisgreatlyinfluencedbythecomponentsofthe•roofassembly.Thetypeandarrangementofthecomponentsgoverntheirpotentialforignitionandtheirpropensitytotransferheatintotheinteriorofthebuilding.Thecomplexityoftheroof’sshapealsoinfluencesthepotentialforignition.Aroofwithvalleys•androof/wallintersectionswherecombustibledebrissuchasleavesandneedlescancollecthasmorepotentialforignitionthanaroofwithoutthem.

Fire-rated Roof AssembliesTheresistanceofroofassembliestoexternalfireisratedbytheAmericanSocietyofTestingandMaterials(ASTM),usingtestmethodE108.Themethodincludesmeasurementsofthesurfacespreadofflame,theabilityoftheroofassemblytoresistfirepenetrationfromtheexteriorofthebuildingtotheundersideoftheroofdeck,andthepotentialfortheroofcoveringtodevelopflyingbrandsofburningmaterial.RoofassembliesareratedClassA(highestrating),B,orC.Assembliesthatfailthetest(donotmeettheClassA,B,orCcriteria)areunrated.

ClassAprovidesthegreatestdegreeoffireresistance,butthereisarangeofprotectionwithintheClassArating.Forexample,someClassAratedassemblieshavenoncombustibleroof

Roof covering: Theexteriorroofcoverorskinoftheroofassembly(e.g.,shingles,tiles,slate,metalpanels,roofmembrane).

Roof assembly:Anassemblyofinteractingroofcomponents,includingtheroofdeck,vaporretarder(ifpresent),insulation(ifpresent),insulationcoverboards(ifpresent),andtheroofcovering.

ASTME108testconditionsdonotreplicateactualwildfireconditions.Inmanycases,actualwildfireexposuresaremuchmoreseverethanthoseinducedduringthetesting.

Page2of5 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 5 – Roofs

coverings(suchasclayorconcretetilesandmetalpanels),whileothershavecombustiblecoverings(suchasasphaltshinglesandlow-slopemembranes).

Guidance for New BuildingsManytypesofroofassembliesareratedClassA.RecommendationsforvariouscomponentsofroofassembliesthatareratedClassAareprovidedbelow.

Steep-slope Roof: CoveringAsteep-sloperoofisaroofwithaslopegreaterthan3:12.Thefollowingdesignandinstallationpracticesarerecommended:

Tile. • Clayandconcretetilearenoncombustibleandbecauseoftheirrelativelylargethermalmass,retardthetransferofheat.Lightweighttileproductsareavailable,butnormal-weighttilesarerecommendedbecauseoftheirgreatermass.Iftilesareinstalledoverwoodbattens,embersmaybeblownunderthetilesandignitethebattens.Fire-retardant-treatedbattensarethereforerecommended.Iftileisused,thefollowingarealsorecommended:

Eaves, hips, and ridges. – Emberscanbeblownundertilesattheeaves,hips,andridges.Birdscanbuildnestsinthespacebetweentheunderlaymentandthebottomofthetilesifthespaceisaccessible,providingcombustibledebristhatcanbeignitedbyembers.Installingbirdstopsateavesandfullymortaringhipsandridgesarebothrecommendedtoavoidtheaccumulationofdebrisundertilesandtokeepembersout(seeFigure1).Valleys. – Unlessspecialmetalflashingisinstalled,combustibledebriscanaccumulateinvalleysandthenunderthetiles.Flatandplaintilesshouldbespecifiedtobetightlybuttedtoformaclosedvalley,andpiecesofmetalflashingshouldbeinstalledundereachtilecoursealongthevalleycenterline.Forprofiledtile,leadorflexibleflashingshouldbeused,asrecommendedbythetilemanufacturer(seeFigure2).

Metal shingles and panels.• Metalshinglesandpanelsarenoncombustible,buttheyreadilytransferheat.Iftheyareinstalledoverwoodbattens,fire-retardant-treatedbattensshouldbespecifiedandinstalled.Ifshinglesorpanelsareinstalledoverwooddecking,5/8-inchgypsum

Figure 1.Abirdstopattheeave.

Birdstops prevent debris from accumulating under tiles

OnlyClassAratedroofassembliesarerecommendedforhomesinwildfirezones.

FS No. 5 – Roofs HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of5

roofboardcomplyingwithASTMC11771 shouldbeinstalledoverthedecking.Fiberglass-reinforced asphalt shingles.• Althougharoofassemblythathasfiberglass-reinforcedasphaltshinglescanberatedasClassA,theseshinglescontaincombustiblematerial(e.g.,asphalt).Ifthistypeofshingleisused,a5/8-inchgypsumroofboardthatcomplieswithASTMC1177overthewooddeckingshouldbeinstalledforenhancedprotectionofthedecking.Careneedstobetakenwhentheshinglesarenailedthatthenailsarenotoverdriven.Wood shingles and shakes• . RoofassembliesthathavewoodshinglesandshakescanberatedClassAiftheshinglesorshakesarefire-retardant-treatedandaspecificcapsheetunderlaymentisinstalled.Withouttheunderlayment,themaximumratingisClassB.Notethatwhenshinglesorshakesarefire-retardant-treated,theycannotbeimpregnatedwithpreservativetreatment.Iffire-retardant-treatedshinglesorshakesareinstalledoverwooddecking,installinga5/8-inchgypsumroofboardthatcomplieswithASTMC1177overthedeckingisrecommendedinadditiontothespecialunderlaymentthatisrequiredtoachievea ClassArating.

Steep-slope Roof: Underlayment Emberscanbeblownundersometypesofsteep-slopecoveringssuchastile,slate,andmetalshinglesandpanels.Iftilesbecomedislodgedorcracked,emberscanlandontheunderlaymentbelow(seeFigure3).Installinganunderlaymentthathasenhancedfireresistanceisrecommendedtoprovideprotectionfromembersthatreachtheunderlayment.

Anexampleofanenhancedunderlaymentisamineral-surfacecapsheetthatisratedforuseinaClassAratedassembly.2Ifamineral-surfacecapsheetisusedundermetalpanelsorshingles,measuresshouldbetakentopreventthemetalfrombearingdirectlyonthecapsheetandthecapsheetfromabradingthemetal(therebymakingthemetalsusceptibletocorrosion).

1Boardsthatare5/8-inchthickaretypeX(“specialfire-resistant“).Boardsthatare1/2-inchand1/4-inchthickarenottypeX.

2Althoughcapsheetsarenormallythefinishedsurfaceofabuilt-upormodifiedbituminousroofcovering,acapsheetcanalsobeusedasanunderlayment.

Figure 3. Displacedtilesallowemberentry.

Figure 2.Specialvalleyflashingtoavoiddebrisaccumulationbetweenandbelowtiles(photographcourtesyofMonierLifetile).

Page4of5 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 5 – Roofs

Steep-slope Roof: Decking Mosthomeshaveroofdecksthatareconstructedofwood,typicallyplywoodororientedstrandboard.Fire-retardant-treateddeckingcanbespecifiedtoavoidignitionofthedeck.Formoreprotection,5/8-inchgypsumroofboardscanbespecifiedinadditiontothefire-retardant- treateddeck.

Althoughnotcommoninhomes,noncombustibledeckssuchassteelorconcrete,includingconcretetoppingoversteeldecking,canbespecified.Inadditiontobeingnoncombustible,concretedecksoffergreatresistancetoheattransferandfirepenetrationthroughthedeckfromtheexterior.

Low-slope Roof: Covering and UnderlaymentLow-sloperoofshaveslopeslessthan3:12.Avarietyoflow-sloperoofcoveringsandassembliesareavailablewithaClassArating.

Ifalow-slopeassemblyisselected,thefollowingrecommendationsshouldbefollowed:Polyisocyanurateroofinsulationshould•bespecified(seeFigure4).A5/8-inchgypsumroofboardthat•complieswithASTMC1177immediatelybelowtheroofmembrane(seeFigure4)shouldbespecified.Forenhancedfireresistance,inadditiontotheaboverecommendations,theroofmembrane•shouldbeprotectedwithheavyweight(i.e.,17poundspersquarefootminimum)concretepavers(seeFigure5).

Ifpaversareplacedoverabuilt-upormodifiedbitumenmembrane,alayerofextruded –polystyreneinsulation(intendedforprotectedmembranesystems)overthemembraneshouldbespecified.

Figure 5.Concretepaversovermembrane(FEMA55).

Mortar-faced extruded polystyrene

Roofparapet

Extruded polystyrene

Concrete pavers

Membrane

Polyisocyanurate insulation

Roof membrane

5/8-inch gypsum board

Roof deck

Figure 4. Componentsofalow-slopedroof.

FS No. 5 – Roofs HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page5of5

Additionally,forsmooth-surfacedbuilt-upandmodifiedbitumenmembranes,asheet –ofpolyethylene(minimumof4mils)shouldbespecifiedbetweenthemembraneandpolystyrenetokeepthepolystyrenefrombondingtothemembrane.Toprotectthebaseflashings,amortar-facedextrudedpolystyreneboardshouldbeinstalled –overthebaseflashing(seeFigure5).

Low-slope Roof: Decking Roofdeckingdesignandconstructionarethesameforsteep-slopeandlow-sloperoofs.Seethediscussionundersteep-sloperoofsabove.

Guidance for Existing BuildingsForhomeownerswithroofassembliesthatarenotClassArated,theonlylong-term,reliablewaytoreduceroofvulnerabilitytowildfireistoreroof.Reroofingnormallyinvolvesremovingthematerialsabovetheroofdeckandreplacingthemwithnewmaterials.Therecommendationsthatarelistedabovefornewbuildingsareapplicabletoreroofingdesignandinstallation.

RoofassembliesthathavewoodshinglesorshakesandarenotratedClassAandroofswithorganic-reinforcedasphaltshinglesarevulnerabletoawildfire.Thesetypesofroofsshouldbereplacedassoonaspossible.

ConsiderationsThehomeownershouldhaveroofdebrisremovedfromtheroofsurfaceandguttersregularly.•Agingdoesnotaffecttheignitionpotentialoftile.However,someroofcoverings,suchaswood•orfiberglass-reinforcedasphaltshingles,becomemoresusceptibletoignitionastheyage.Theroofcoveringshouldbereplacedbeforedeteriorationofthecoveringsignificantlydegradesresistancetoignition.Birdstopsshouldbeinspectedannuallytoensurethattheyhavenotfallenoutofplace.•Forrecommendationsonvents,seeFactSheet#8,Vents.•Forrecommendationsonguttersanddownspouts,seeFactSheet#9,Guttersand•Downspouts.

EffectivenessAllmitigationmeasuresrecommendedinthisFactSheetareeffectiveinallFireSeverityZones.

ResourcesAmericanSocietyofTestingMaterials(ASTM).2007.Standard Test Methods for Fire Tests of Roof

Coverings.ASTME108-07a.

FEMA.2003.Coastal Construction Manual.FEMA55.

FS No. 6 – Eaves, Overhangs, and Soffits HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of3

Eaves, Overhangs,and Soffits Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 6

Purpose Toprovideguidanceonthedesignandconstructionofeaves,overhangs,andsoffitsinwildfirezones.Theguidancepertainstobothnewandexistingbuildings.

Key IssuesWindborneembers,convectiveheat,andradiantheatcanbetrappedunderoverhangsand•intheupperportionofexteriorwalls.Overhangsandwallscanigniteifnotconstructedofnoncombustibleorfire-resistantmaterials.Typicalconstructionmaterialsforeaves,overhangs,andsoffitsarenotfire-resistantandare•thereforesusceptibletoignitionbyembersandhotgases.Onceaneave,overhang,orsoffithasignited,firecanspreadontotheroof,intotheattic,or•ontoandthroughtheexteriorwall.Soffitsnormallyhaveventsaspartoftheatticventilationsystem.Unprotectedventscanallow•embersandhotgasestoentertheattic(seeFactSheet#8,Vents).

Typical Design and ConstructionEaves. Eavesarelocatedatthedown-slopeedgeofaslopedroofandserveasthetransitionbetweentheroofandfascia/wall.Aneavetypicallyhasametaledgeflashingandgutterthatareattachedtoawoodfasciatrimboard.

Overhangs. Overhangsareextensionsoftheroofbeyondtheexteriorwall(i.e.,thejoists,rafters,ortrussesandthedeckingtheysupportcantileverpastthewall).Anoverhangprotectstheupperportionofthewallthatitisattachedtofromrainfall,anditalsoshadesthewindowsunderitfromthesun.Overhangscanbeopen,inwhichthetrusses/raftersanddeckingareexposed(seeFigure1),orenclosedbyasoffit.

Soffits.Asoffitenclosestheundersideofsloped-orflat-roofoverhangs.Soffitsarecommonlyconstructedfromfiber-cementpanels,metalpanels,stucco,vinylpanels,orwoodsheathing.Metalpanels,untreatedwoodpanels,andvinyl

Attic vents

Figure 1. Anopenoverhang.Theexposedtimberraftersanddeckingaresusceptibletoignition,andembersandhotgasescanentertheatticthroughunprotectedvents.

Page2of3 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 6 – Eaves, Overhangs, and Soffits

panelsarevulnerabletodamagefromwildfires.Metalpanelsconductheatandcandistortandallowpassageofembersandhotgases.Untreatedwoodpanelscanignite,andvinylpanelscanmeltandfallaway.

Guidance for New BuildingsConsiderdesigningthebuildingwithout•overhangs(seeFigure2)toavoidthefire-relatedproblemsassociatedwithsoffitsorminimizeasmuchaspossibletheextentoftheoverhangtoreducethepotentialforentrapmentofembersandhotgases.Ifnooverhangsorshortoverhangsare•unacceptablebecauseofaestheticsoradesiretoprotectthewallsfromrainfallorwindowsfromthesun,implementthefollowingrecommendedmeasures:

Encloseoverhangswithsoffitsthathave –aminimum1-hourfire-resistanceratingtopreventembersandhotgasesfrommakingcontactwiththejoists,raftersortrusses,ortheundersideoftheroofdecking.Useflat,horizontalsoffits(seeFigure3)insteadofattachingthesoffitstotheslopedjoists, –whichcreatesslopedsoffits.Aflatsoffitreducesthepotentialforentrapmentofembersandhotgases.

Forthefascia,usenoncombustibleorfire-resistantmaterials(e.g.,fire-retardant-treated•lumber,fiber-cementboard).Foreavevents,followtheguidanceinFactSheet#8,Vents.•

Embers and hot gases from fire

Exterior wall cladding

Fascia

Gutter

Rafter

Underside of roof deck

Figure 3. An enclosed overhangwithahorizontalsoffit.

Figure 2.Aneavewithessentiallynooverhang.

Gutter

Embers and hotgases from fire

Horizontalsoffit

Exterior wall cladding

Fascia

RafterUnderside of roof deck

Soffit framing

FS No. 6 – Eaves, Overhangs, and Soffits HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of3

Guidance for Existing BuildingsInstallasoffitunderopenoverhangsaccordingtotheguidanceprovidedabove.•Evaluatethefire-resistanceofexistingsoffitsandreplacesoffitsthatarenotfire-resistant•accordingtotheguidanceprovidedabove.Someexistingsoffits(suchasthoseconstructedofplywood)canbecoveredwithanoncombustibleorfire-resistantmaterialsuchasfiber-cementboardorstucco.InveryhighFireSeverityZones,installexterior5/8-inchfire-resistantgypsumboardbetween•theexistingandnewsoffitmaterialsforenhancedfireresistance.Ifthefasciaiscombustible,coverthefasciaboardwithanoncombustibleorfire-resistant•material(e.g.,fire-retardant-treatedlumber,fiber-cementboard).Foreavevents,followtheguidanceinFactSheet#8,Vents.•

ConsiderationsPlantingcombustiblevegetationundereavesandoverhangsshouldbeavoided(seeFactSheet#4,DefensibleSpace).

EffectivenessAllmitigationmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZones.

ResourcesUnderEaveSFMStandard12-7A-3,2001CaliforniaReferencedStandardCodes(Part12,

Title24,C.C.R.).http://www.fire.ca.gov/fire_prevention/downloads/Part_12_CA_SFM_12-7A-3_Test_Standards.pdf.

FS No. 7 – Exterior Walls HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of3

Exterior Walls Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 7

PurposeToprovideguidanceonthedesignandconstructionofexteriorwallsinwildfirezones.Guidancepertainstobothnewandexistingbuildings.

Key Issues • Exteriorwallsaresusceptibletowildfireflames,conductiveheat,andradiantheat.Flamesandheatcanignitecombustiblewallcoverings.Whenexteriorwallsignite,thefirecanspreadtoothercomponentsofthebuildingsuchastheroof,soffit,windows,anddoors,resultinginsubstantialdamagetoortotallossofthebuilding.

• Windborneembersandfirebrandsarealsosourcesofignition.Emberscanbecometrappedincracksinwalls,windowopenings,anddoortrimboardsandignitecombustiblematerials.Windbornefirebrandscanignitewallcoverings.

• Thefireresistanceofexteriorwallsdependsprimarilyonwhatthewallsareconstructedofandtheamountofnearbycombustiblematerial.Sometypesofconstructionmaterialssuchasvinylsidingdonotburnbutcanmeltwhenexposedtohightemperatures(seeFigure1),allowingthefiretoreachtheunderlyingwallcomponentsandpenetratetheinteriorofthebuilding.

Guidance for New Buildings• Forthebestprotection,ensurethatexteriorwallcoveringsarenoncombustibleorfire-resistantandnotsusceptibletomelting.Concrete,fiber-cementpanelsorsiding,exteriorfire-retardant-treatedwoodsidingorpanels,stucco,masonry,andmetalarerecommendedmaterials.Withthesecoverings,thecoveringitselfshouldnotigniteandfuelthefire.Examplesofthetypesofcoveringsthatarenotrecommendedarewoodsidingthatisnotfire-retardant-treated,vinylsiding,metalsidingsusceptibletowarping,andanexteriorinsulationfinishsystem.

• Ensurethattheentirewallassemblyhasafire-resistanceratingtestedinaccordancewithAmericanSocietyforTestingandMaterials(ASTM)E119.Althoughtheaboverecommendedtypesofcoveringsprovideaninitialbarriertoflames,heatmaypassthroughthecovering

Figure 1.Vinylsidingthatmeltedandwarpedduringawildfire(firecenter.berkeley.edu).

Page2of3 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 7 – Exterior Walls

andigniteunderlyingwallcomponents.Afire-resistanceratingindicateshowlongundertestconditionsawallassemblycanpreventflamesandheatfrompassingthroughthewall.Aminimumfire-resistanceratingof1hourisrecommended,buthigherratingsprovidegreaterprotection.

• Complywiththerequirementsofthefire-ratedassembly,includingusingtheexacttypeofmaterials,configuration,andattachmentusedduringthetestingthatestablishedtherating.

• Forexceptionalfireresistance,useinsulatedconcreteform(ICF)walls,cast-in-placeconcrete,orfullygroutedconcretemasonryunits.IfICFisselected,useastuccoormasonrywallcoveringtoprotecttheplasticfoamforms.

• Iffiber-cementormetalwallcoveringsareused,installonelayerof5/8-inchtypeXexteriorgypsumboardwithtapedjointsunderneathhousewrap(seeFigure2).Forfiber-cementsiding,thegypsumboardprovidessecondaryprotectionifthesidingdecomposesandfallsawayduringafire.Formetalpanels,thegypsumboardminimizesthetransferofheatradiatedfromthemetalpanelstootherwallcomponents.

• Forvinylsiding(notethatvinylsidingisnotrecommended),installonelayerof5/8-inchtypeXexteriorgypsumboardwithtapedjointsunderneathhousewrap.Ifthevinylandhousewrapmeltduringafire,theunderlyinggypsumboardwillprovidesomeprotection.

• Usenoncombustibleorfire-resistantmaterialsuchasexteriorfire-retardant-treatedwoodorfiber-cementfortrimboardsarounddoors,windows,eaves,andcorners.

Guidance for Existing Buildings• Replaceexteriorwallcoveringsthatarecombustible,aresusceptibletomelting,orcanreadilytransmitheatwithoneoftherecommendedcoveringslistedabove.Examplesofthetypesofcoveringsthatneedtobereplacedarewoodsidingthatisnotfire-retardant-treated,vinylsiding,metalsiding,andanexteriorinsulationfinishsystem.

Beforereplacingvinylormetalsiding,checkwhetherthereisanunderlyinggypsumboard –substrate.Ifso,remedialworkmaynotbeneeded.

Determinewhetherkeepingtheexistingcoveringandcoveringitwith5/8-inchtypeX –gypsumboardandanewcoveringisaviableoption.

Considerations• Forstudwalls,metalstudscanbeusedinlieuofwoodstuds.Metalstudsdonotignite,buttheytransferheatmorereadilythanwoodstudsandcandeformandcollapseattemperaturesthatcanoccurinawildfire.Currentdataareinsufficientregardingthewildfireperformanceof

Figure 2.Exampleofafire-ratedwallassembly.

Exterior covering

Wall stud

Sill plate

5/8-inch type X exterior gypsum board

Wood sheathing

Housewrap

FS No. 7 – Exterior Walls HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of3

wallsthathavewoodstudsversusmetalstuds.• Maintainingandremovingcombustibledebris(suchasvegetationandleaves)andfirewoodneartheexteriorwallsregularlyreduceabuilding’svulnerabilitytoignitionduringawildfire(seeFactSheet#4,DefensibleSpace).

EffectivenessAwallassemblywithoneoftherecommendedcoveringsandaminimum1-hourfire-resistanceratingiseffectiveinallFireSeverityZones.

ResourcesASTME119-08aStandardTestMethodsforFireTestsofBuildingConstructionandMaterials.

http://www.astm.org/Standards/E119.htm.

MaterialsandConstructionMethodsforExteriorWildfireExposure:ExteriorWallSidingandSheathingSFMStandard12-7A-1,2001CaliforniaReferencedStandardCodes(Part12,Title24,C.C.R.).http://www.fire.ca.gov/fire_prevention/downloads/%20Part_12_CA_SFM_12-7A-1_Test_Standards.pdf.

FS No. 8 – Vents HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of5

Vents Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 8

Purpose Toprovideinformationaboutwaystoavoidwindborneembers,convectiveheat,andradiantheatenteringexteriorventopenings,whichcanleadtotheignitionofinteriorbuildingcomponentsandcontents.Guidancepertainstobothnewandexistingbuildings.

Vent Systems and Vent OpeningsVentscanbedividedintothoseforattics;ventilatedcathedralceilings;crawlspaces;andheating,ventilation,andairconditioning(HVAC)systems.

Attic and Cathedral Ceiling Vents Ridge vent• —acontinuousventinstalledalongthefulllengthoftheroofridge.Ridgeventsallowexfiltrationofatticair,orinventilatedcathedralceilingsorventilatednailbaseboards,theexfiltrationofairfromtheventilationcavityofthecathedralceilingornailbaseboards.Ridgeventsaremetalorplastic.Someridgeventshaveinternalbafflemediatoavoidtheentranceofwind-drivenrainandsnow.Soffit vent• —acontinuousorintermittentventinstalledalongasoffit.Soffitventsprovideairintakeintotheatticorintotheventilationcavityofcathedralceilingsandventilatednailbaseboards.Soffitventsaremetalorplasticandoftenhaveascreentopreventinsectentry.Vinylandmetalsoffitsarecommonlyventedbyintermittentlyspaced,perforatedsoffitpanels.Gable-end vent• —aventlocatedinthegable-endwall,justbelowtheroofridge.Gable-endventsallowairtoflowintoandoutofattics.Gable-endventsnormallyhavelouverbladestoavoidtheentranceofwind-drivenrainandsnow(seeFigure1).Thistypeofventiscommonlymetalandnormallyhasaninsectscreen.Through-roof vent• —aventthatpenetratestherooftoallowexfiltrationofatticair;alsoknownasaneyebrowordormervent.Through-roofvents,includingsheetmetal“goose-necks,”arealsoavailableforkitchenorbathroomexhaustducts.Through-roofventsaremetal,plastic,orrigidfiberglass.

Figure 1. Alouveredventopeningcanbeusedforgable-endventingorforconnectiontoductwork.

Horizontal louvers can prevent embers from entering the ventilation system

Page2of5 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 8 – Vents

Crawlspace VentsCrawlspace vent• —aventinstalledintermittentlythroughthefoundationwallseveralinchesabove-grade.Crawlspaceventsallowairtoflowintoandoutofthecrawlspace.

HVAC System VentsThrough-roof vent• (seeabove).Wall louvers• —aventopeningonanexteriorwall(seeFigure1).WalllouversareconnectedtotheHVACductworkwhereairentersorisexhaustedfromthebuilding.Louversarecommonlymetal.Thelouverbladesarenormallyinafixedposition(i.e.,cannotberotated),butsomehavemoveablebladesthatcanberotatedtoclosetheventopening.

Key IssuesEmbersandhotgasescanbeblownorpulled•intoventopeningsandenteratticspaces,crawlspaces,andductwork,leadingtoignitionoftheinteriorofthebuilding(seeFigure2).Debriscanaccumulateatventopeningsand •igniteduringawildfire.

Guidance for New Buildings

All Vents Specifyandinstallnoncombustiblematerialforallvents.Metalproductsarerecommendedfor•ventsandventflashing.Specifyandinstallcorrosive-resistant,metalmeshscreenswithamaximumopeningof•1/4inchatallventopenings.Specifyandinstallventopeningswithamaximumnetfreeareaof144squareinches.•Placeallventopeningsatleast10feetfromotherbuildingsorpropertylinestoavoidignition•fromembersandhotgasesfromanadjacentbuildingthathasignited.

Attics (including Cathedral Ceiling and Ventilated Nailbase Boards) Protectingatticspacesfromwildfiresisachallengebecauseairisnaturallydrawnintoatticsthroughventopenings.Althoughinsectscreenscanpreventtheentryofmanyembers,ventscreensandlouversdonotpreventtheentryofhotgases.Ventsthatallowairtoflowintoandoutundernormalconditionsandalsoavoidtheentryofembersandhotgasesinawildfirecanbeprovidedinthefollowingways:

Gable-end vent• .Insteadofusingridgevents,specifyandinstallgable-endventswithspeciallydesignedmetalshutters.Whenawildfirethreatens,theshutterscanbeplacedoverthegable-endvent.Ahingedshutterthatcanbelatchedinanopenorclosedpositionisrecommended(seeFigure3).Adetachableshutterdesigncanbeused,butwhentheshuttersareneeded,

Figure 2. Embersorhotgasescanbeblownorpulledintovents.

FS No. 8 – Vents HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of5

thehomeownermustrememberquicklywheretheyarestored.Shuttersshouldhaveagasketthatprovidesatightsealbetweentheshutterandgable-endvent.Foramoreconservativeshutter,ashutterwithaninsulatedcoreencapsulatedbymetal(similartoarefrigeratordoor)canbeused.Whengable-endventsarecombinedwithsoffitvents,effectiveatticventilationcanbeachievedwhentheatticspaceissimpleandrelativelysmall,suchasasmall,gable-roofedhouse.Ifthehousehasacomplexroofareaortheatticistoolargetobeeffectivelyventilatedbygable-endvents,ridgeventsorthrough-roofventsshouldbeused.Ridge vent• .Continuousridgeventscanprovideeffectiveventilation,buttypicalridgeventsarenothighlyfire-resistant.Althoughairisnormallyexhaustedthroughridgevents,hotgasescanentertheridgeventandflowintotheattic.Emberscanalsoenterthroughtheridgeventiftheventdoesnothaveinternalbafflemedia.Typicalridgeventsarethereforenotrecommendedunlesstheatticconfigurationorsizerequiresridgeventstoventilatetheatticeffectively.Ifridgeventsareused,metalventswithinternalbafflemediaarerecommended,butduringawildfire,theinternalbafflematerialmaymeltandbecomeineffective in atpreventingembersfromentering.Soffit vent• . Aswithridgevents,typicalsoffitventsarenothighlyfire-resistant,butbecausetheyareanecessaryelementofaventedattic,theycannotbeeliminated.Toavoidembersandhotgasesfromenteringthevents,speciallydesignedmetalshuttersoverthesoffitventopeningsshouldbespecifiedandinstalled.Seetheshutterrecommendationsforgable-endventsabove.Through-roof vent• . Through-roofventsarenotrecommendedforatticventilationbecausethereisnoknowneffectivestrategyforavoidingembersandhotgasesfromentering,otherthanblockingthevent.A1/4--inchscreeniseffectiveatkeepingoutfirebrandsandembersthatarelargerthan1/4-inchbutwillnotkeepoutsmallerembersorhotair.

Shutter with fire-resistant gasket

Shutter latched in open position

Wall louver vent

Shutter manually latched in closed position at the onset of a wildfire

The Unventilated AtticThemostconservativeapproachtopreventingembersandhotgasesfromenteringtheatticistoeliminateatticventilation,butunventilatedatticsarecontroversial.AlthoughallowedbytheInternationalResidentialCode,providedtheCode’scriteriaaremet,unventilatedatticsmaynotcomplywithlocalbuildingcodes.

However,whenunventilatedatticsareallowedbythebuildingcodeorcodecomplianceisnotanissue,andwhenclimaticandinteriorhumidityconditions(e.g.,noindoorswimmingpools)areconducivetoanunventilateddesign,anunventilatedatticisareliablewaytopreventembersandhotgasesfromenteringtheattic.

Figure 3.Ahingedshutter.

Page4of5 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 8 – Vents

Becauseofvariablereliabilityofblockingtechniquesandthepotentialdangerofhomeownersfallingfromroofswhileattemptingtoblockvents,blockingisnotrecommended.

Crawlspace Vents Specifyandinstallspeciallydesignedmetalshuttersovercrawlspaceventopenings.A1/4-inchmeshscreenshouldalsobeinstalledovertheventopening.Seetheshutterrecommendationsforgable-endventsabove.

HVAC System VentsWall louvers• . Specifyandinstallspeciallydesignedmetalshuttersoverwalllouvers(seetheshutterrecommendationsforgable-endventsabove)orspecifyandinstallwalllouversthathaveadjustabletight-fittingbladesthatcanbeclosedwhenawildfirethreatens.Asanadditionalconservativemeasurewitheithershuttersoradjustableblades,specifyandinstallfiredamperswithintheductsimmediatelybehindthewalllouvers.Ifsufficientlyhighheatpenetratesbeyondthelouver,thefiredamperwillautomaticallycloseandpreventhighheatfrompenetratingfarther.Through-roof vents• .Asdiscussedinatticventilation,through-roofventsarenotrecommended.Ratherthanrunningductworkthroughtheroof,extendtheductworktoanexteriorwallwhereitcanbefittedwithawalllouverandshutter.Ifitisnecessarytopenetratetheroof,however,installafiredamperintheductattheplaneoftheroofassembly.

Guidance for Existing Buildings Ifthehomehasridgeventsorwalllouversandtheyarenotmetal,replacethemwithmetal•ventsaccordingtotheguidanceprovidedabove.Ifexistingventopeningsdonothavescreensorifthescreenopeningsarelargerthan•1/4-inch,installmetalscreensaccordingtotheguidanceprovidedabove.Installshuttersovergable-endvents,soffitvents,crawlspacevents,andwalllouvers.Ifthe•existingwallorsoffitiscombustible,shuttersmaynotbeeffective.Inthiscase,installingshuttersisprobablycost-effectiveonlyifdoneinconjunctionwithupgradestothewallorsoffit.

ConsiderationsLow-profile,through-roofventshavebeenusedinplaceofsoffit/eaveventswithgreatsuccess,•butnoneoftheseproductshavebeentestedatthetimeofthispublication.Thehomeownershouldperiodicallyhaveaprofessionalremovedebristhathasaccumulated•nearoronventopenings,ventscreens,andlouverblades.Theamountofvegetationnearventopeningsshouldbelimited(seeFactSheet#4,Defensible•Space).Tominimizethepossibilitythatembersandhotgaswillbepulledintothehome,theHVAC•system,includingexhaustfans,shouldbeturnedoffwhenawildfirethreatens.Atticexhaust

FS No. 8 – Vents HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page5of5

fansshouldalsobeshutdown.Atticexhaustfansthatarecontrolledbyathermostatmayneedtobedeactivatedbytrippingthecircuitbreaker.Forsoffitconstruction,seeFactSheet#6,Eaves,Overhangs,andSoffits.•

EffectivenessAllmitigationmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZonesexceptasnotedbelow.Ifaridgeventisinstalled,theventopeningmaybebreachedduringextremefireexposureby•embersorhotgases,whichcouldresultinignitionoftheattic.Theeffectivenessofshutter-protectedventopeningsisdependentonthedeploymentofthe•shuttersbythehomeownerpriortofireexposure.

ResourcesSlack,P.2000.Firewise Construction Design and Materials.ColoradoStateForestService.

UnderEaveSFMStandard12-7A-3,2001CaliforniaReferencedStandardCodes(Part12,Title24,C.C.R.).Availableatwww.fire.ca.gov/fire_prevention/downloads/Part_12_CA_SFM_12-7A-3_Test_Standards.pdf.

FS No. 9 – Gutters and Downspouts HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of2

Gutters and Downspouts Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 9

PurposeToprovideguidanceaboutinstallingfire-resistantguttersanddownspoutstoreducethepotentialfordamagetohomesandotherbuildingsfromwildfires.Guidancepertainstobothnewandexistingbuildings.

Key IssuesDebrissuchasbranches,leaves,andpineneedlescan•becometrappedingutters(seeFigure1).Thedebriscanbeignitedbyflyingembersorfirebrandsduringawildfire,andthefirecanspreadtotheroof.

Guttersanddownspoutsareoftenconstructedof•plastic.Plasticcanmeltwhenexposedtothehightemperaturesthatcanoccurduringawildfire.

GuidanceInstallnoncombustibleleafguardsoverguttersto•preventtheaccumulationofcombustibledebris.Typesofleafguardsincludemetal-meshscreensandmetalhoodsthatfitintothegutter(seeFigure2).

Useguttersanddownspoutsconstructedof•noncombustiblematerialssuchasgalvanizedsteel,copper,andaluminum.Metalhoodleafguardsarerecommendedbecausetheydonotmeltandarerelativelyeffectiveinkeepingdebrisoutofgutters(seeFigure2).

ConsiderationsIntenseheatfromawildfirecandistortnoncombustible•gutters,leafguards,anddownspouts,andtheymayneedtobereplacedafterawildfire.

Someleafguardscanbecomedislodgedovertime,reducingtheireffectiveness.•

Figure 2.Leafguardsallowrainwaterintothegutterbutkeepcombustibledebrisout.

Leaf guard

Figure 1. Debrisingutterscanigniteandleadtoignitionoftherooforfasciaboard.

Page2of2 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 9 – Gutters and Downspouts

Sometypesofleafguardsdonotpreventalltypesofdebrisfromaccumulatinginthegutter.•Forexample,mesh-typeleafguardsallowpineneedlestoaccumulate.Leafguardsandguttersshouldthereforebecheckedregularlyanddebrisremovedifnecessary.

EffectivenessNoncombustiblegutters,leafguards,anddownspoutsareeffectiveinallFireSeverityZones.

FS No. 10 – Windows and Skylights HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of4

Windows and Skylights Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 10

PurposeToprovideinformationaboutmeasuresthatcanbetakentoavoidtheignitionofinteriorbuildingcomponentsandcontentsduetotheintrusionofwindborneembers,hotgases,andradiantheatthroughwindows,slidingglassdoors,doorvisionpanels,andskylights.Guidancepertainstobothnewandexistingbuildings.

Key IssuesGlazinginhomesistypicallyvulnerabletowildfire•(seeFigure1).(“Glazing”referstotheglass,plastic,orfiberglass-reinforcedtranslucentmaterialinwindows,slidingglassdoors,doorvisionpanels,andskylights.)Failedglazingallowseasypassageofembers,hotgases,andradiantheatintotheinteriorofthebuilding.Glazingisvulnerabletowildfireintwoways:

Flameimpingementandradiantheatcanbe –severeenoughtomeltorbreakmanytypesofglazing.Asinglepaneoftypicalresidentialglasscanfailwithin5minutesofexposuretoawildfire(Slack,2000).Windbornefirebrandscanhavesufficient –momentumtobreakmanytypesofglazing.

Theframesforwindows,slidingglassdoors,and•skylightsareconstructedofmetal,plastic,wood,oracombinationofthesematerials.Plasticandwoodenframesaresusceptibletofailurefromburningormelting(seeFigure2).Iftheframeorsashfails,theentireglazingmayfallout.

Guidance on New BuildingsThissectionprovidesguidanceonglazing,frames,fire-ratedassemblies,andexteriorwindowshutters.

Figure 1.Potentialdamagetoawindowduringawildfire.

Embers melt vinyl frames and ignite wooden frames

Radiant heat and windborne firebrands can shatter windows and lead to interior damage

Figure 2.Combustibleframing(firecenter.berkeley.edu).

Page2of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 10 – Windows and Skylights

Glazing Avarietyofproductsareavailableforglazinginwindows,slidingglassdoors,doorvisionpanels,andskylights.Glazingcanbeinasingle-ormulti-panedconfiguration.Therecommendedglazingproductsforhomesinwildfirezonesarelaminatedglass,temperedglass,glasswithalow-emissivity,fiberglass-reinforcedtranslucentglazing,andinsulatedglazingunits(IGUs).Glazingproductsthatarenotrecommendedareannealedglass,ceramicglass,andplasticglazing.

RecommendedLaminated glass• . Laminatedglassprovidesresistancetowindbornefirebrands.Ifafirebrandstrikeswithenoughmomentumtobreaktheglass,theplasticfilminthecoreoftheglasswillkeeptheglazingintheframe,allowingthebrokenglasstocontinuetoresistfirebrandimpacts,embers,andhotgases.Iftheplasticfilminthecoregetssufficientlyhot,thepanewilldelaminatewhetherornottheglasshasbeenbroken.Iflaminatedglassisspecified,itshouldeitherbeprotectedbyshutters,asdiscussedbelow,orcombinedwithtemperedglassinanIGU.SeetheinformationonIGUsbelow.Tempered glass• .Temperedglassismoreresistanttoheatandflamesthanlaminatedglassorannealedglass(seebelow).Theresistanceoftemperedglasscanbeenhancedwithalow-ecoatingoraproprietaryreflectivecoating,asdiscussedbelow.Firebrandswithsufficientmomentumcanbreaktemperedglass.Toavoidbreakage,theglasscanbeprotectedbyshutters,asdiscussedbelow.AnotheralternativeistospecifyandinstallanIGUwithalaminatedglassinnerpane.Low-emissivity (low-e) coating• . Glasswithalow-ecoatingprovidesahigherlevelofresistancetoradiantheatthanothertypesofglazingbecausethecoatingreflectsradiantheat,reducingtheprobabilitythattheheatwillbeabletoenterthebuilding.Thecoatingshouldbeontheinnersurfaceoftheexteriorpane.Proprietary fiberglass-reinforced translucent glazing• .Thisproductisavailableforskylightsandwalls.TheskylightmaterialhasaClassArating.SeeFactSheet#5,Roofs,foradiscussionofthistypeofrating.Insulated glazing unit. • AnIGUconsistsoftwoorthreepanesofglassthatareseparatedbyasealedairspace.Double-panedannealedunitslastabout10minutesinawildfire,twiceaslongassingle-panedwindows.Inmanycases,10minutesislongenoughtoprovideprotectionfromthefire.Ifthefirstpanefails,thesecondpanemuststillbepenetrated(Slack,2000)(seeFigure3).Laminatedglass,temperedglass,andglasswithalow-ecoatingcanbecombinedinvariouswaysintoanIGU.

Two panes of glass with a layer of air between

The first pane may shatter within 5 minutes of theonset of a wildfire

The second pane offers 5 minutes of additional protection

Figure 3. Double-panedglazing.

FS No. 10 – Windows and Skylights HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of4

NotRecommendedAnnealed glass• .Annealedglass(alsoknownascommonfloatglass)iscommonlyusedinresidentialwindows.Annealedglassisthemostsusceptibletowildfiresofthevariousglasstypesandisnotrecommendedforhomesinwildfirezonesunlessprotectedbyshutters,asdiscussedbelow.Ceramic glass.• Thisspecialtyglassiseffectiveatresistingflames,butittransmitsradiantheatreadily.Ifceramicglassisusedforexteriorglazing,heatthatishighenoughtocauseignitioncanbetransmittedintotheinteriorofthebuilding.Ceramicglassisnotrecommendedforhomesinwildfirezones.Plastic glazing.• Acrylicandpolycarbonateareoftenusedinskylightsandsometimesinwindows.Becauseplasticglazingcanmeltduringawildfire,itisnotrecommendedforhomesinwildfirezones.

FramesAvarietyofproductsareavailableforwindowandskylightframes.Toavoidwindowfailure,framesshouldbeconstructedonlyofmetalormetal-cladwood.Woodenandplasticframesshouldnotbeused.

Fire-rated AssembliesIfafire-ratedwallisspecified,windowsandslidingglassdoorsthatarecommensuratewiththewallintermsofthefireratingarerecommended.Forexample,awindowwitha1½-hourratingisintendedtobeusedinawallwitha2-hourrating,andadoorwitha3/4-hourratingisintendedtobeusedinawallwitha1-hourrating.However,awindowwithahigherfireratingmaybeused.SeeFactSheet#7,ExteriorWalls,forinformationaboutfire-ratedwalls.

Ifafire-ratedwallisnotspecified,anIGUwithametalormetal-cladwoodenframeshouldbeused.SeetheinformationonIGUsabove.

Exterior Window ShuttersExteriorwindowshutterscanprovideprotectionforwindowsandslidingglassdoorsinawildfire.Solidmetalshuttersareunlikelytoigniteormeltandarethereforerecommendedoverwoodenorplasticshutters(seeFigure4).Forenhancedprotection,aninsulatedmetalshuttercanbedesignedandfabricated.Ifthebuildingislocatedinawindbornedebrisregionwithinahurricane-proneregion,theshuttershouldmeetthewindbornedebriscriteriaintheAmericanSocietyofCivilEngineersstandard,ASCE7-05(2006).

Figure 4. Thismetalshutterhastopandbottomtracksthatarepermanentlyanchoredtothewall(FEMA577).

Page4of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 10 – Windows and Skylights

Guidance on Existing BuildingsWindowsandslidingglassdoors,includingframes,thataresusceptibletodamagefrom•awildfireshouldbereplacedwiththecomponentsthatarerecommendedaboveand/orprotectedbyshutters,asrecommendedabove.Doorvisionpanelsthataresusceptibletodamagefromawildfireshouldbereplacedwith•temperedglasswithalow-eorproprietaryreflectivecoating,providedthedoorhassufficientfireresistance(seeFactSheet#11,ExteriorDoors).Skylightswithplasticglazingshouldbereplacedwithoneoftherecommendedtypesof•glazing,asdescribedabove.

ConsiderationsShuttersprotectthehomenotonlyfromwildfiresbutalsofromextremeweather.•Double-panedglassismoreenergyefficientthansingle-panedglass.•Aproprietaryreflectivecoatingisavailableforapplicationtotemperedglass.Thecoatingacts•likealow-ecoatinginthatitreflectsradiantheat,buttheproprietaryreflectivecoatingmaybemoreeffective.Formoreinformationonthisproductandacomparisonoffireratingsofvarioustypesofglassproductsandsizes,seewww.safti.com.

EffectivenessWindowassemblieswith3/4-hourminimumratingsareeffectiveinallFireSeverityZones.•Metalcladdingonmetalclad-woodframesmaybecomedistortedduringwildfireexposureand•requirereplacement.Temporaryshuttersareeffectiveonlyifthehomeownerhassufficienttimetoputtheshutters•intoplace.

ResourcesAmericanSocietyofCivilEngineers.(2006).Minimum Design Loads for Buildings and Other

Structures.ASCE7-05.

CenterforFireResearchandOutreach.UniversityofCalifornia,Berkeley:CollegeofNaturalResources.http://firecenter.berkeley.edu/default.htm.

ExteriorWindowsSFMStandard12-7A-2,2001CaliforniaReferencedStandardCodes(Part12,Title24,C.C.R.).http://www.fire.ca.gov/fire_prevention/downloads/Part_12_CA_SFM_12-7A-2_Test_Standards.pdf.

FEMA.2007.Design Guide for Improving Hospital Safety in Earthquakes, Floods, and High Winds: Providing Protection to People and Buildings. RiskManagementSeries,FEMA577. http://www.fema.gov/library/viewRecord.do?id=2739.

FireRatedGlazingSolution.www.safti.com.

Slack,P.2000.Firewise Construction Design and Materials. ColoradoStateForestService.

FS No. 11 – Exterior Doors HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of3

Exterior Doors Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 11

Purpose Toprovidebasicguidanceonthedesignandconstructionofexteriordoors,includinggaragedoors,onbuildingsinwildfirezones.Guidancepertainstobothnewandexistingbuildings.

Key IssuesExteriordoorsaresubjecttothesame•typesofexposureasexteriorwallsinawildfire(seeFigure1).However,exteriordoorsaretypicallymuchthinnerandlessfire-resistantthanexteriorwallsandcanthereforeburnthroughmuchfaster.Flamesandhotgasescanignite•combustiblematerialsinadooranddoorframe.Flamesandhotgasescanpenetrate•openingsbetweenthedoorandframeandbetweenthedoorandthreshold(orfloorifnothresholdexists).Emberscanbecomelodgedinopenings•betweenthedoorandframeandbetweenthedoorandthreshold(orfloorifnothresholdexists).Emberscanalsobeblownthroughtheopeningsintotheinteriorofthebuilding.Flames,convectiveorradiantheat,and•airbornefirebrandscanbreakglassinadoor.

Exterior Door Characteristics and RatingsTypesofexteriordoorsincludesolidentrancedoors,entrancedoorswithglassvisionpanels,slidingglassdoors,stormdoors,screendoors,garagedoors,andcellardoors.

Solidexteriordoorsaretypicallymadeofwoodormetal.Doorswithasolid,noncombustiblemineralcoreareclassifiedasfire-rateddoorsandareratedbyUnderwritersLaboratories(UL)accordingtothelengthoftimetheycanresistfire(ULStandard10C)(UL,1998).UL

Figure 1. Typesofexposurethatexteriordoorscanbesubjecttoinawildfire.

Welcome Welcome

Embers can become lodged in openings and separations

Radiant heat can shatter glass

Radiant heat and embers can ignite combustible materials and penetrate through openings

Page2of3 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 11 – Exterior Doors

classificationsforinteriorandexteriorfire-rateddoorsandtheirframesrangefrom3-hourto20-minuteratings.Exteriorfire-rateddoorsareavailablewitharatingof1½houror3/4hour.

Thefireratingfordoorsisintendedtoequalthree-fourthsofthefireratingofthesurroundingwall.Forexample,adoorwitha1½-hourratingisintendedtobeusedinawallwith2-hourrating,andadoorwitha3/4-hourratingisintendedtobeusedinawallwitha1-hourrating.However,adoorwithahigherfireratingmaybeused.

Guidance for New BuildingsIfafire-ratedexteriorwallisspecified(seeFactSheet#7,ExteriorWalls),specifyandinstalla•fire-rateddoorandframe.Asexplainedabove,theratingofthedoorandframeshouldbeatleastthree-fourthsoftheratingofthewall.Inaddition,specifyandinstallfire-ratedhardware.FollowtheguidancepertainingtodoorglassvisionpanelsandglassslidingdoorsinFact•Sheet#10,WindowsandSkylights.Toavoidembersandhotgasespenetratingtheinteriorofthebuildingbetweenthedoor•andthedoorframe,installadjustableweatherstrippingontheinteriorsideofthedoorframeandspecifyandinstallanautomaticdoorbottomorthresholdweatherstripping.TheweatherstrippinganddoorbottomshouldbetestedinaccordancewithULStandard10C.Weatherstrippingisrelativelyinexpensive(seeFigure2).Garagedoorsaretypicallymadeofwood,aluminum,orsteel•andareinsulatedornon-insulated.Unlikestandardegress/ingressdoors,garagedoorsarenotnormallytestedforfireresistance(seeFigure3).Toprotectthegaragedoorandentirebuilding,followtheguidancelistedbelow.

Specifyandinstallinsulated,metalgaragedoors. –

Toavoidembersandhotgasespenetratingthegarage, –specifyandinstallweatherstrippingthathasbeentestedinaccordancewithULStandard10Caroundtheentiregaragedoor.

Figure 2.Exampleofadjustableweatherstripping(FEMA577).

Fire-resistant weatherstripping

Noncombustible or fire-resistant trim

Insulated metal door

Figure 3.Agaragedoorwithnoncombustibleandfire-resistantcomponents.

Door

Adjustablejambweatherstrip

FS No. 11 – Exterior Doors HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of3

Forexteriortrimthatcoverstheopeningbetweenthedoorframeandexteriorwall,specifyand•installnoncombustibleorfire-resistantmaterialsuchasfire-retardant-treatedwoodorfiber-cementboard.

Guidance for Existing BuildingsAddweatherstrippingtodoors,asdescribedabove.•Replacevisionpanelsindoors,ifnecessary,asdescribedinFactSheet#10,Windowsand•Skylights.Replaceslidingglassdoorsand/orprotectwithshutters,asdescribedinFactSheet#10,•WindowsandSkylights.Replacewoodengaragedoors,particularlyiftheydonothaveasolidcore.•Replacewoodenegress/ingressdoorswithoutasolidcore,althoughegress/ingressdoorsare•oftenrelativelyfire-resistantcomparedtoothercomponentsofthebuildingandthereforenotnormallyahighpriorityforremediation.

ConsiderationsMetalandmetal-claddoorframescantransmitheatduringafire,andtheheatcanignitethesurroundingexteriorwallifthewallisnotconstructedtofire-resistantstandards,asnotedabove.Formoreinformation,seeFactSheet#7,ExteriorWalls.

EffectivenessAllmitigationmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZonesexceptasfollows:Garagedoorsarenotnormallytestedforfireresistanceandmaynotprovideeffectivefire•resistanceinhighFireSeverityZones.Underveryhighheatorprolongedexposuretoheat,weatherstrippingmaterialcanmeltor•burn,loweringitseffectivenessinpreventingembersandhotgasesfromenteringtheinteriorofabuilding.

ResourcesFEMA.2007.Design Guide for Improving Hospital Safety in Earthquakes, Floods, and High Winds:

Providing Protection to People and Buildings.RiskManagementSeries,FEMA577.http://www.fema.gov/library/viewRecord.do?id=2739.

SteelDoorInstitute(SDI).2001.Basic Fire Door Requirements. TechnicalDataSeriesSDI118-01. http://www.steeldoor.org/res/118.pdf).

UnderwritersLaboratory(UL).1998.ULStandard10C,PositivePressureFireTestsofDoorAssemblies.

FS No. 12 – Foundations HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of4

Foundations Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 12

PurposeToprovideguidanceonavoidingtheignitionoffoundationsbywindborneembersandconvectiveandradiantheatinwildfirezones.Guidancepertainstobothnewandexistingbuildings.

Foundation DesignsFoundationscanbeopenorclosed.Homesnormallyhaveonlyonetypeoffoundation,butsomehaveboth.

Closed FoundationInaclosedfoundation,thefoundationwallextendsfromthefootingtothefirstflooraroundtheperimeterofthebuilding.Thefoundationwallistypicallyabearingwall.Thebelow-gradeportionistypicallyconstructedofconcreteormasonry,butpreservative-treatedwoodcanalsobeused.Theabove-gradeportionmayalsobeconstructedofconcreteormasonry,oritmaybeastudwall(commonlyreferredtoasa“cripplewall”;seeFigure1).Thefoundationwallenclosesabasement,acrawlspace,orthesoilbelowaslab-on-grade.

Open FoundationInanopenfoundation,thebuildingissupportedbypilesorpiers,andthebottomofthefirst-floorframingisseveralfeetabove-grade(seeFigure2).Pilesandpiersareconstructedofconcrete,masonry,timber,orsteel.Someoftheareabelowthefirstfloormaybeenclosedwithwallsforanelevatorortocreateasmallstoragearea.1 Wood latticeisalsooftenplacedbetweenpiles/pierstoprovideaprivacyscreen(forexample,aroundcars parkedunderthebuilding).Manufacturedhousing 1 IfthehomeisinFloodHazardZoneV,seeTechnicalFactSheet27,EnclosuresandBreakawayWalls,inHome Builder’s

Guide to Coastal Construction,TechnicalFactSheetSeries(FEMA499).www.fema.gov/rebuild/mat/mat_fema499.shtm.

Figure 1.Aclosedfoundationwithacripplewall(FEMAfieldteam).

Figure 2.Anopenfoundation.

Page2of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 12 – Foundations

istypicallysupportedonanopenfoundation,butoftenanon-bearingwall(skirting)isinstalledaroundtheperimeterofthehomebetweengradeandthefloor.

Key Issues

Closed Foundation Directflame,embers,orhotgasescanenterthroughcrawlspaceventsorbreachedbasement•windows.Thecrawlspacewallorwallcoveringortheexposedportionofthebasementwallorwall•coveringcanbeignitedbydirectflame,embers,orhotgases.Oncethewallisignited,thefirecanpenetratethecrawlspaceorbasementandclimbuptheexteriorwall.Combustibleitemsstoredinbasementsorcrawlspaces(suchashouseholdgoodsincardboard•boxes)canbecomefuelinafire.

Open Foundation Theundersideofthefirstfloorcanbeignitedbydirectflame,embers,orhotgases.Whenpiles•orpiersareconstructedoftimber,thepile/pierisnormallythickenoughtoresistignition.SeeFactSheet#13,DecksandOtherAttachedStructures,forinformationonignitionresistanceasafunctionoftimberwidth.Woodlatticescreenscanbeignitedbydirectflame,embers,orhotgases.Latticescreens•oftentrapcombustibledebrissuchasleavesandpaper,increasingthepotentialforignition.Ignitionofalatticescreencanleadtoignitionoftheundersideofthefirstfloor.Wallsandwallcoveringsaroundenclosuressuchaselevatorshaftsandstorageareascanbe•ignitedbyembersorhotgases,leadingtoignitionoftheundersideofthefirstfloor.Combustibledebrisorstorageitems(suchasfirewoodorgasinacontainer)inanopen•foundationcanbeignited,leadingtoignitionoftheundersideofthefirstfloor.Skirtingaroundtheperimeterofmanufacturedhomescanbeignited,leadingtoignitionofthe•undersideofthefloorandspreadofafireuptheexteriorwall.

Guidance for New Buildings

Closed FoundationSeeFactSheet#7,ExteriorWalls,forguidanceonwallsandwallcoverings.•SeeFactSheet#8,Vents,forguidanceoncrawlspacevents.•SeeFactSheet#10,WindowsandSkylights,forguidanceonwindows.•

Open FoundationToavoidignitionofthefirst-floorframingmembers(joists)andfloordecking,sheaththeundersideoftheframingasfollows:

FS No. 12 – Foundations HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of4

Attach5/8-inchthickexteriortypeX•gypsumboardtotheundersideofthejoists.Forenergyconservation,installbattinsulationbetweenthejoists(seeFigure3).Attachfire-retardant-treatedplywood,•fiber-cementpanels,ormetalsidingpanelsoverthegypsumboard.Donotinstalllatticescreens.Ifscreens•areinstalled,usechain-linkfencingwithmetalprivacyslatsinsteadofwood.Forguidanceonenclosurewalls•aroundstorageareasandforskirtingonmanufacturedhomes,seeFactSheet#7,ExteriorWalls.Forguidanceonwindows,seeFactSheet#10,WindowsandSkylights.Forguidanceondoors,seeFactSheet#11,ExteriorDoors.

Guidance for Existing Buildings

Closed FoundationSeeFactSheet#7,ExteriorWalls,forguidanceonwallsandwallcoverings.•SeeFactSheet#8,Vents,forguidanceoncrawlspacevents.•SeeFactSheet#10,WindowsandSkylights,forguidanceonwindows.•

Open FoundationIfthefirst-floorframingmembersaretimbermemberslessthan3inchesthick(nominal)orif•thefloordeckingiscombustible,sheaththeundersideoftheframingasdescribedabove.Evaluatefloorbeamsandjoiststhatareconstructedofsteel(notcommoninresidential•construction).Dependingonavarietyofconditions,itmaybeprudenttosheaththeundersideoftheframingasdescribedaboveorprotectthesteelwithsuitablefireproofing.Removeexistinglatticescreensorreplacethemwithchain-linkfencingwithmetalprivacyslats.•Forguidanceonenclosurewallsaroundstorageareasandforskirtingonmanufactured•homes,seeFactSheet#7,ExteriorWalls.Forguidanceonwindows,seeFactSheet#10,WindowsandSkylights.Forguidanceondoors,seeFactSheet#11,ExteriorDoors.

ConsiderationsThehomeownershouldperiodicallyremovecombustibledebrisunderbuildingswithopen•foundations.

Figure 3.A5/8-inchtypeXgypsumboardattachedtotheundersideofthejoists.

5/8-inch type X gypsum

Joist

Subfloor

Exteriorcladding

Batt insulation

Page4of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 12 – Foundations

Thehomeownershouldnotstorecombustibleitemssuchasgasandfirewoodunderbuildings•withopenfoundations.Ifabuildingisexposedtoawildfire,anengineershouldevaluatethestructuralintegrityofthe•foundation.Inareaswheredryrotisaconcern,fire-retardant-treatedplywoodcanbeattachedoverthe•gypsumboardontheundersideofthefloorjoists,butplywoodisaffectedmorebyweatherelementsthanfiber-cementpanelsormetalsidingpanels.Ifthebuildingislocatedinafloodplain,asdesignatedbyFEMA’sNationalFloodInsurance•Program,criteriasetforthinTitle44CodeofFederalRegulationsPart60shouldbeconsidered.

EffectivenessAllmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZones.

ResourcesFEMA.2005.Home Builder’s Guide to Coastal Construction Technical Fact Sheet Series.

FEMA499.http://www.fema.gov/rebuild/mat/mat_fema499.shtm.

FEMA.2006.Recommended Residential Construction for the Gulf Coast: Building on Strong and Safe Foundations.FEMA550.www.fema.gov/library/viewRecord.do?id=1853.

Slack,P.2000.Firewise Construction Design and Materials.ColoradoStateForestService.

FS No. 13 – Decks and Other Attached Structures HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of4

Decks and Other Attached Structures Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 13

PurposeToprovideguidanceontheconstructionofdecksandotherattachedstructuresonhomesinwildfirezones.Otherattachedstructuresincludebalconies,porches,stairs,andramps.Allofthesestructurescanbeasourceoffuelduringawildfire.Ignitionbyflamesorfirebrandscanleadtoignitionoftheexteriorofthebuilding,resultinginsubstantialdamagetoortotallossofthebuilding.

Key IssuesDecksareoftenbuiltatthetopofaslopeinthedirectlineofthemostlikelyapproachofa•wildfire,puttingthesedecksatahighriskofignition.Buildinganddeckorientationisthereforeimportantinreducingtheriskofexposuretoawildfire(seeFactSheet#3,SelectingtheConstructionSite).Decksconstructedofdimensionedlumberarecombustibleandsubjecttoquickignition.•Embers,firebrands,andhotgasescanbecomelodgedortrappedunderdecksandother•attachedstructures,wherethestructuresattachtothebuilding,andinthegapsbetweenboarddecking.Theycanalsosettleagainstexteriorwallsandaccumulateatrailingedges.Allofthesethingsincreasetheriskofignitionofthesestructuresandignitionofthehome.

Guidance for New Decks and Other Attached Structures

SitingOrientdecksandotherattachedstructurestoavoidexposuretothepathofawildfire.Avoidconstructingthesestructuresnearheavilyvegetatedareasandtopographicfeaturessuchassteepslopes,gullies,canyons,saddles,ridgetops,andnarrowmountainpasses(seeFactSheet#3,SelectingtheConstructionSite).

Construction Materials Useheavytimberornoncombustiblematerials(seeFigure1).Thefollowingmaterialsarerecommended:Forcolumns,useaminimum6-inch• ×6-inchtimberor concreteblockorsteel.

Figure 1. Deckconstructedofheavytimber.

Decking: 3-inch nominal thickness

Columns: 6-inch x 6-inch

Joists: 3- or 4-inch nominal thickness

Railing: metal

Page2of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS 13 - Decks and Other Attached Structures

Forfloorjoistsandbeams,useheavytimber,3-inchto4-inchnominalthicknessfire-retardant-•treatedwood,orconcreteblockorsteelframing.Forrailings,useminimum3-inchnominalthicknessfire-retardant-treatedwood• ormetal,cables,ortemperedglass.Fordeckingandstairtreads,useexteriorfire-retardant-treatedwood,minimum3-inchnominal•thickness,orbrickorconcretepaversandasuitabledrainagematoverwooddeckingormetalgrates.Light,pouredconcretemayalsobeasuitabledeckcovering.

Duetoinsufficientdatacomparingtheperformanceofplasticandcompositematerialstoheavytimberdeckingwhenexposedtoflamesandheat,FEMAdoesnotrecommendtheuseofplasticorcompositedeckinginhighFireSeverityZones.However,theUniversityofCalifornia’sCenterforFireResearchandOutreach(Berkeley)hasconductedsometestingonplasticandcompositematerialsusedindecks.Resultsareasfollows:Plasticandcompositeproductswithchannelsontheundersideofthedeckingdegradedearly•whenexposedtounder-deckfires.Productswithhollowconstructionexhibitedboardcollapsewhenexposedtofirebrands.•Someproductswithasolidconstructionperformedsimilarlyto2-inchthicknominalwood•decking,butmanydidnotperformaswellasheavytimberdecking.

Moreinformationonthetestingisavailableathttp://www.fire.ca.gov/fire_prevention/downloads/Part_12_CA_SFM_12-7A-4_Test_Standards.pdf.

Construction TechniquesIsolatetheattachedstructurebysurroundingitwith•noncombustiblematerialsuchasgravel,brick,orconcretepaverstopreventvegetativegrowthandreducefuelinawildfire(seeFigure2).Enclosetheundersideofthedeckwithfire-resistant•skirtingthatactsasashieldagainstembersandreducestheprobabilitythatradiatedandconvectedheatwillignitethedeck(seeFigure2).Topreventemberintrusioningapsbetweenthe•deckingandhome(suchasinoffsetledgerboardconstruction),coverthegapswith1/8-inchmetalscreening.Installflashingonledgerboardsthatareattachedwithoutgapstocreateabarriertoembersandpreventwaterfrompenetrating(seeFigure3).Coverexposedfloorframingattheundersideof•attachedstructureswithafire-resistantsoffitsuchasfiber-cementpanels.Thesoffitshouldhaveweepholeswithamaximumdiameterof1/4inchtoallowwaterthatleaksthroughthedeckingtodrainoutofthesoffitspace.

Figure 2. Deckisolatedbyapatio.

Surround deck with noncombustible patio

Enclose the deck with fire-resistant skirting

FS No. 13 – Decks and Other Attached Structures HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of4

Guidance for Existing Decks and Other Attached StructuresToenhancetheperformanceofexistingdecksandotherattachedstructures,thefollowingarerecommended:Replacecombustiblematerialswithnoncombustibleorfire-resistantmaterials.•Replacedimensionaltimberrailingswithrailingsconstructedoffire-resistantmaterialssuch•asmetal,temperedglass,cables,or3-inchnominalthicknessfire-retardant-treatedwood(seeFigure4).Whenthedeck,balcony,stairs,orrampcanaccommodateorbereinforcedtoaccommodate•additionalload,installbrickorconcretepaversandasuitabledrainagematovertheexistingdecking(seeFigure4).

Figure 3. Deckflashing.

Figure 4. Concretepaversoverexistingdeck.

Deck flashing

Deck joist

Exterior wall cladding

Exterior wall sheathing

Fiber-cement board

Flashing

Waterproof membrane

Concrete pavers

Existing deck

Existing joist

Gypsum soffit

Metal railing

Page4of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS 13 - Decks and Other Attached Structures

Constructdeckskirtingaroundthedeckusingfire-resistantornoncombustiblematerialsuch•asfiber-cementboardsand/orconstructapatioonthegroundaroundthedeck,stairs,orramp.Installasoffitattheundersideofbalconies,decks,stairlandings,orrampswhenskirtingisnot•installed(seeFigure4).

ConsiderationsMaintenanceandremovalofcombustible•debrisandvegetationaroundandunderdecksandotherattachedstructuresisakeyfactorinreducingvulnerabilitytoignitionduringawildfire(seeFigure5).Formoreinformationondefensiblespace,seeFactSheet#4,DefensibleSpace.Decksandotherattachedstructuresshould•bemaintainedbyreplacingdeterioratedcomponentsbeforetheylosetheirfire-resistance.Decksenclosedwithfire-resistantskirting•mustbeventedformoisturecontrol(seeFactSheet#8,Vents).

EffectivenessAllmitigationmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZones.

ResourcesDecking:SFMStandard12-7A-4.2001CaliforniaReferencedStandardCodes(Part12,Title24,

C.C.R.).http://www.fire.ca.gov/fire_prevention/downloads/Part_12_CA_SFM_12-7A-4_Test_Standards.pdf.

UniversityofCaliforniaAgricultureandNaturalResources.FirePerformanceTesting:Decks.http://firecenter.berkeley.edu/quarles/deck_kit-SQ.pdf.

Figure 5. Combustibledebrisunderthisdeckignitedandledtothedestructionofthedeck.Althoughthesidingisnoncombustible,thefirespreadfromthedeckthroughawindowtotheinterior(firecenter.berkeley.edu).

FS No. 14 – Landscape Fences and Walls HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of3

Landscape Fences and Walls Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 14

PurposeToprovideguidanceaboutlandscapefencingandwallsthatareattachedtoornearbuildingsinwildfirezonestoreducethepotentialfordamagetothebuildingsfromawildfire.

Key Issues Landscapefencesandwallsfunctionas•physicalorvisualbarriersorarchitecturalstatements.Propertyownersdonotalwaysconsiderthepotentialthatlandscapefencesandwallscanhaveincontributingtothespreadofawildfire.Thecommonwoodenpost-and-boardfence•canbecomefuelforawildfire,especiallywhenthefenceisoldandweather-beaten.Thistypeoffencecanalsocollectembersandfirebrandsinawildfireandactasahorizontalladderfuelbyallowingthefiretotravelalongthefencetowardthemainbuilding(seeFigure1).Onceignited,afenceorwallconstructedof•combustiblematerialsthatisattachedtoornearabuildingcanignitethebuildingthroughradiantorconvectiveheatorbydirectflamecontact.

Guidance Usenoncombustiblematerialsforfencesandwalls.Fencesandwallsvaryinshape,size,and•constructionmaterials,allofwhichprovidevaryingdegreesofprotectionorriskinawildfire.Typicalmaterialsusedinfencesandwallsarewood,plastic,composite,metal,wire,concrete,stone,andmasonry.Ofthesematerials,woodisthemostcombustible,whileconcrete,stone,andmasonryarenoncombustible.

Wood. – Fencesthatareconstructedofwoodorhavewoodencomponentsarecombustibleandthereforeprovidenofireresistance.Combustiblematerialssuchassoftwoodsandpinetreatedwithpreservativesshouldbeavoidedifthefenceisattachedtothebuilding.Densehardwoodssuchasredoak,whiteoak,hickory/pecan,andwalnutaremorefire-resistantthanpinesandothersoftwoods.

Figure 1.Thegatethatwasattachedtothegarageatthecornerignitedandledthefiretothehome,causingthedamageseenhere(firecenter.berkeley.edu).

Page2of3 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 14 – Landscape Fences and Walls

Plastic. – Plasticfencesaremorefire-resistant,moredurable,andoftenstrongerthanwoodenfences,butplasticfencescanmeltinawildfirefromtemperaturesthatarebelowthemaximumawildfirecangenerate(seeFigure2).Metal. – Metalfencesaremorefire-resistantthanplasticfences.Wirefencessuchasbarbedwire,hogwire,andchainlinkhavelittleornoeffectonfirepassage.However,ifcombustiblematerialshaveaccumulatedinoraroundthefenceorthefencecontainscombustiblematerialssuchaswoodenposts,thefencecanactasahorizontalladderfuelbyallowingthefiretotravelalongthefencetowardthemainbuildingConcrete, stone, or masonry. – Concrete,stone,andmasonryfencesandwallsarenoncombustibleandcanactasabarriertoawildfirebydeflectingflamesawayfromabuilding,butthepassageofairborneembersandfirebrandswillnotbesignificantlyaltered.Thesematerialsarethemosteffectiveatminimizingthepotentialfordamagetoabuildingfromawildfire.

Avoidattachingfencesandwallsconstructedofcombustiblematerialstoabuilding.•Forfencesandwallsthatareattachedtoabuilding,ensurethatallcombustiblecomponents•areatleast10feetfromthebuildingtopreventheatandflamesfromignitingthebuilding.Avoidfencesthathavegaps,suchaswoodenslatfences,becauseairbornefirebrandscan•becometrappedinthegapsandignitethefence(seeFigure3).

Figure 2.Plasticfencescanmeltevenundermoderatewildfiretemperatures(FEMAfieldteam).

Figure 3. Keyguidanceforfences.

Avoid fences with gaps because airborne firebrands can become trapped in the gaps and ignite the fence

Clear combustible debris and vegetation near the fence regularly; vegetation growing on or around a fence can ignite, leading to ignition of the fence

FS No. 14 – Landscape Fences and Walls HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of3

ConsiderationsThephysicalconditionofthefenceorwallshouldbemaintained.•Combustibledebrisnearthefenceorwallshouldbeclearedregularly(seeFactSheet#4,•DefensibleSpace).Thetypeoflandscapevegetationthatisplantednexttoafenceorwallshouldbeconsidered,•andthevegetationshouldbemaintainedregularly.Unmanagedlandscapevegetationcanincreasetheprobabilitythatthefencewillignite,especiallyafencethatisconstructedofcombustiblematerials(seeFigure3).Formoreinformationondefensiblespace,seeFactSheet#4,DefensibleSpace.

EffectivenessMasonry,concrete,stone,metal,andhardwoodlandscapefencesandwallsareeffectiveinallFireSeverityZones.

ResourcesAmericanHardwoodInformationCenter.http://www.hardwoodinfo.com/species_guide/

brochure_44-45.pdf

CenterforFireResearchandOutreach.UniversityofCalifornia,Berkeley:CollegeofNaturalResources.http://firecenter.berkeley.edu/default.htm.

FiresafeCouncil.http://www.firesafecouncil.org/.

FirewiseCommunitiesProgram.http://www.firewise.org/.

FS No. 15 – Fire Sprinklers HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of4

Fire Sprinklers Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 15

PurposeToprovideguidanceontheinstallationofinteriorandexteriorfiresprinklersystemsonbuildingsinwildfirezones.Theguidancepertainstobothnewandexistingbuildings.

Key IssuesDuringawildfire,firebrandsandairbornedebriscanbreachwindows,andconvectiveheatand•emberscanpenetrateutilityopenings,gapsarounddoors,andotheropenings.Theinteriorofabuildingcanigniteevenwhentheexteriordoesnot.Firesprinklersarenotcommoninresidentialconstruction,buttheycanbeeffectiveinpreventingdamagefromawildfire.Exteriorbuildingcomponentsthatarecombustiblesuchasoverhangsandrecessedalcoves•cantrapembers,firebrands,andhotgases,leadingtoignitionofthebuilding.Exteriorsprinklerscanhelpextinguishflamesbeforethebuildinghasbeensubstantiallydamaged.Abuildingthathasignitedcanendangernearbybuildingsandcontributetothespreadofa•wildfire.Interiorandexteriorsprinklerscanpreventsubstantialdamagetothebuilding,protectnearbybuildings,andpreventthefirefromignitingnearbycombustiblevegetation.

Interior Fire Sprinklers

Common Misconception FactAllsprinklersinasystemactivatesimultaneously.

Onlysprinklerheadsthatareinanareaofhighheatareactivated.Typically,onlyoneortwoheadsactivateduringafire.Sprinklerheadsareactivatedonlybyheat,notbysmoke.

Sprinklerscanactivateaccidentally. AccordingtotheU.S.FireAdministration,only1in16millionsprinklerheadsactivatesaccidentally.

Waterdamagefromsprinklersismoreexpensivetorepairthandamagefromthefire.

Waterdamagefromsprinklersisusuallyconsiderablylessexpensivetorepairthandamagecausedbywaterfromfirehoses,smoke,andfire.Quick-responsesprinklersrelease8to24gallonsofwaterperminute,whilefirehosesrelease50to125gallonsperminute.

Interiorsprinklersystemsareobtrusiveandnotaestheticallypleasinginresidences.

Interiorfiresprinklersforsingle-familyresidencesaresmallerthantraditionalcommercialorindustrialfiresprinklersandcanbecoordinatedwithanyroomdécor.Sprinklerheadscomeinavarietyofstyles,models,andcolorsandcanbemountedflushwiththeceiling(seeFigure1)orconcealedbehindcovers.

Page2of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 15 – Fire Sprinklers

CharacteristicsI• nteriorfiresprinklersystemscandetectadevelopingfirequicklyandactivateautomatically.Systemsdonotrequiremanualintervention.Interiorsprinklersystemscanincludeawarningsystem•thatnotifiesoccupantsandemergencyresponsepersonnelofadevelopingfire.Interiorsprinklerscanbeinstalledduringnew•constructionorinanexistinghome.

GuidanceInstallingsprinklersinunoccupied,enclosedspaces•suchasatticsshouldbeconsideredbecausedoingsocanprovideadditionalprotectioniffirepenetratestheexteriorofthespace.Waterpressureandsupplymustbothbeadequateforaninteriorsprinklersystemtobe•effective.Wateristypicallysuppliedbythewatermainfromthemunicipalwatersupply.Duringawildfire,firefightingresourcesoftenexhausttheavailablewaterpressure.Ifexistingwaterpressureisinadequateorthesourceofwaterisawell,aholdingtankcanbeusedasawatersource.Toensurethatwaterisavailabletothesystemduringawildfire,apressurizedholdingtankshouldbeconsidered,evenifthestructureisconnectedtothemunicipalwatersupply.

ConsiderationsThemajorityofthecostofaninteriorsprinklersystemisassociatedwiththepipingmaterial.•Optionsformaterialsincludesteelalloys,copper,andfire-resistantplastics.Plasticpipingislessexpensivethansteelalloysandcopper,butitsmeltingpointisasmuchasfivetimeslowerthancopperpiping.Hazardinsuranceratesaretypicallydiscountedforhomeswithinteriorsprinklersystems.•Aninteriorsprinklersystemisrelativelyeasytoinstallduringnewconstruction.Thesystem•increasesthetotalcostofconstructionbyapproximately2percent;complexandmulti-storyinstallationsmayincreasethecostmore.Installinganinteriorsprinklersystemcanbedonewhentheroofisreplacedorupgraded,anddoingsomaycostlessthanstandardinstallation.Thecostofinstallinganinteriorsprinklersystemduringnewconstructionisabouthalfthecost•ofinstallingasysteminanexistingbuilding.

EffectivenessInternalsprinklersextinguishthefireatanearlystageandpreventsubstantialdamagefromheatandsmokeortotallossofthestructure.TheyareeffectiveinallFireSeverityZones.

Figure 1.Aconcealed,aestheticallypleasingfiresprinkler.

Sprinkler head ceiling cover

FS No. 15 – Fire Sprinklers HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of4

Exterior Fire Sprinklers

Characteristics Thepurposeofanexteriorfiresprinklersystemistosaturatetheexteriorofthebuilding.•Exteriorsprinklersystemscanbeinstalledduringnewconstructionoronexistingbuildings.•Theyarecommonlyinstalledontheroofalongtheridgelineorunderneaththeeavesandalongsoffits.Exteriorsprinklerscanbeactivatedautomaticallybylow-voltageheatdetectorsormanuallyby•occupantsbeforetheyevacuatethehome.Exteriorsprinklerscanincludeawarningsystemthatnotifiesoccupantsandemergency•responsepersonnelofadevelopingfire.Somelandscapesprinklersaredesignedandinstalledtoprovideprotectionfromawildfireto•landscapeareasimmediatelysurroundingabuilding.Anexteriorsprinklersystemcanbeinstalledsothatitissubstantiallyhiddenfromview.•

GuidanceExteriorsprinklersmountedonthebuildingcanbeconfiguredtousewaterpipingthroughtheatticorroofortousepipingontheexteriorofthestructure.Ifinteriorpipesareused,exteriorsprinklerscanbeinstalledinconjunctionwithinteriorsprinklers(seeFigure2).Astand-alonesystemthatincludesapressurizedholdingtankcanbeconsideredtoensureanadequatewatersupply.Seetheinformationaboutwatersupplyunderinteriorfiresprinklersabove.

ConsiderationsIfexteriorsprinklersareinstalledin•areaswherefreezingtemperaturesoccur,specialprovisionssuchasdrysprinklersarerequiredtopreventwaterinthepipingfromfreezingandrupturingit.Inadrysprinklersystem,theportionofpipingthatisvulnerabletofreezingisnotchargedwithwateruntilafireopensavalveandreleaseswaterintothepiping.Exteriorsprinklerscanprovideaddedprotectionwhenusedinconjunctionwithfire-resistant•constructionmaterials(seeFactSheets#5–14)anddefensiblespace(seeFactSheet#4,DefensibleSpace).Polymergels,ClassAfoamproducts,andotherlong-termfireretardantscanbeappliedto•structurespriortofireimpingementandprovidegreaterthermalprotectionthanwateralone.

Figure 2.Interiorandexteriorfiresprinklerscanbeinstalledinconjunctionwitheachother,suchasthissystemwithasprinklerintheatticandalongtheeave.

System is connected to the water main or a pressurized holding tank

Sprinklers can be installed in the attic and in the eaves

Page4of4 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 15 – Fire Sprinklers

Manyoftheseproductsareavailabletohomeownersinself-containedapplicationunitsandcanbeappliedwithanattachmenttoagardenhoseorintegratedintothehome’sexteriorsprinklersystems.

EffectivenessIfexteriorfiresprinklersrequiremanualactivation,occupantsmustactivatethesystem•expeditiouslyforthesystemtobeeffective.Highwindsthatarefrequentlyabyproductofmajorfireactivitycansignificantlydegradethe•effectivenessofanexteriorsprinklersystem.Manuallyappliedfire-protectionmaterialssuchasClassAfoamproductscanbeeffectiveif•timeisavailabletotreatthehome.Tobeeffective,thefire-protectionmaterialmustbeappliedwithinthetimeframeidentifiedbytheproductmanufacturer.

ResourcesFireSafety.gov.Residential Fire Sprinklers.http://www.firesafety.gov/citizens/sprinklers/index.

shtm.

NationalFireProtectionAssociation.2007.NFPA13D:Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes.http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=13D.

NationalFireSprinklerAssociation.Informationaboutresidentialsprinklersystems.http://www.nfsa.org.

FS No. 16 – Utilities HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page1of3

Utilities and Exterior Equipment Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 16

PurposeToprovideinformationaboutmeasuresthatcanbeimplementedtoprotectutilityconnectionstobuildingsandexteriorequipmentfromawildfire.Guidancepertainstobothnewandexistingbuildings.

DescriptionUtilitiesofalltypesthatpenetrateabuildingcanbeathreattoabuildinginawildfire.Exteriorequipment,suchassolarpanelsandreceiverdishes,canbevulnerabletodamagebythehightemperaturesgeneratedbyawildfire.Thefollowingutilitiesandequipmentareparticularlysusceptibletodamageinawildfire:

Electrical Utilities and Exterior Equipment Electricityisdeliveredtohomesthroughabovegroundconductorsanddroplines(themajorityofhomes)orthroughundergroundcables.Electricityisthenprovidedtoexteriorequipmentbycablesthatareconnectedtotheequipmentfrominsidethehome.

Fuel-related Utilities and Exterior Equipment Manyhomesusepressurizedgas(liquidpetroleumgas,suchaspropaneandbutane,ornaturalgas)orliquidfuel(fueloilorkerosene)forheating,hotwater,andcooking.Propaneandbutanearestoredinpressurizedvessels.Naturalgasisdeliveredthroughpressurizedpipesthatareconnectedtothehome.Liquidfuelisdeliveredtothehomebygravityfromon-sitestoragetanks.

Key Issues

GeneralExteriorequipmentoftencontainscombustible•componentsthatincreasetheriskofignitionoftheequipmentandthebuildingitisattachedto.Mostutilitiesandexteriorequipmentrequirepenetration•ofthebuildingenvelopeforductingandconduit(seeFigure1).Theopeningsmayallowheat,hotgases,andemberstoenterthebuildingandcauseignitionofcombustiblematerialsinthebuildinginterior.

Figure 1.Thegaparoundutilitypenetrationssuchasthisoneshouldbefilled.

Page2of3 09/08 HomeBuilder’sGuidetoConstructioninWildfireZones FS No. 16 – Utilities

Combustibledebriscancollectaroundexteriorequipment,increasingtheprobabilityofignition•oftheequipmentandbuilding.

Electrical Utilities and EquipmentWildfirescanaffectpowertransmissionbyconduction,convection,directflamecontact,and•heavysmoke.Wildfirescandamageequipmentsuchaspowerpolesandpowerlinesorcauseashortcircuitinthelines.Powersurgesandpoweroutagescausedbywindandfirecandamageelectricallypowered•equipmentinhomesthataremilesaway.Aswithanyelectricalpowersupply,waterwellpowersuppliesarevulnerableduringawildfire.•Waterwellsystemscanbeessentialtodomesticandfire-protectionneeds.Equipmentmountedonroofshasthesameignitionpotentialastheroofingassembly.•

Fuel-related Utilities and EquipmentExposed,combustibledeliverylinesarevulnerabletowildfire.Forexample,gasmetersare•vulnerabletowildfiredamageifpipeconnectionsincludearubberizedgasket.Pressurizedandliquidfuelsareflammableandexplosive.•Ventingoffuelunderpressuremaycausesignificantdamageortotaldestructionofabuilding,•dependingprimarilyonthelocationofthefuelcontainer.

Guidance

GeneralIfpossible,installutilityandequipmentconnectionsunderground,includingallentrypoints•intothebuilding.Ifautilityorequipmentconnectioncannotbeinstalledunderground,sealgapsand•penetrationsinexteriorwallsandroofswithfire-resistantcaulk,mortar,orfire-ratedexpandingfoam.Filllargegapswithintumescentorfire-protectivesheetsorpillows.Fire-resistantwrapmaybeusedaroundventilationfeaturesthatarebuiltintoandpenetrateexteriorwalls(suchasairconditioners).

Electrical Utilities and Equipment Shieldpowercablesandotherwiringwithnoncombustibleorfire-resistantmaterialstoprotect•thecablesandwiringfromconvection,radiation,andconductionheat,anddirectflamecontact.Usenoncombustibleorfire-resistantmaterialsformountingsystemsofroof-mounted•equipment.Usesurgeprotectorstoprotectsensitiveelectronicequipment.•

FS No. 16 – Utilities HomeBuilder’sGuidetoConstructioninWildfireZones 09/08 Page3of3

InstallClassAratedsolarcellsystems•forthegreatestprotection.SolarcellsystemsaretestedandratedunderthesameconditionsasroofingassembliesandareavailablewithClassAandClassCratings(seeFactSheet#5,Roofs).

Fuel-related Utilities and EquipmentBuryorshieldfuellinestoprotect•themfromradiation,conductionheat,anddirectflamecontact.Burypressurizedstoragevessels•underground(seeFigure2).Placefuelstoragevessels30feetfromthehomeandawayfromdownhillslopesandenclose•thembehindanoncombustiblemasonrywall.Shieldgasmetersfromhotairandgases,convectionandradiantheat,anddirectcontactby•flame,usingnoncombustiblematerialssuchasmasonryorconcrete.Ensurepressurizedstoragetankshaveapressurereliefvalve.Astheoutsidetemperature•risesinawildfire,thepressureinsidethetankcanincrease.Whenthepressuresettingisexceeded,thevalvewillopenandrelievethepressure,preventinganexplosion.

ConsiderationsReplacingpipes,cables,andotherinstallationscandamagesealantsforwallpenetrations.•Fire-resistantsealantsandnoncombustiblemortarmustberemovedandreplacedeachtimeacableorpipeisreinstalled.Usingdefensiblespaceforthelocationofutilitiesandexteriorequipment(forexample,electric•waterpumps,fueltanks)shouldbeconsidered(seeFactSheet#4,DefensibleSpace).

EffectivenessAllmeasureslistedinthisFactSheetareeffectiveinallFireSeverityZones.

ResourcesFire-resistantexpandingfoamstandards:ASTME814,UL1479,BS476,Part20.

Pressurereliefvalvestandards:ASME(AmericanSocietyofMechanicalEngineers)Boiler&PressureVesselCode,SectionVIIIDivision1andSectionI.

Fuel storage tank

Filler pipeVent

Buried fuel lines

Figure 2.Buriedfuelstoragetank.

FS No. 17 – Community Infrastructure Home Builder’s Guide to Construction in Wildfire Zones 09/08 Page 1 of 5

Community Infrastructure Home Builder’s Guide to Construction in Wildfire Zones Technical Fact Sheet No. 17

PurposeToprovideguidanceaboutneighborhoodandcommunity-widefire-safepracticesthatwillenhancefireprotectioninwildfirezones.Guidancepertainstocommunityinfrastructure,includingroadsusedforevacuationroutesandemergencyaccess,andemergencywatersupply.Althoughahomebuildermaynothavecontrolovertheseelements,communityofficialsandhomeownersshouldbeawareofmeasuresthatcanbetakenonacommunity-widebasistoincreasethechancesofanentireneighborhood’ssurvivalinawildfire.

BackgroundPoorlydesignedorinadequateinfrastructurecanhamperfire-suppressioneffortsandput•citizensandfirefightersatrisk.Reducingtheriskofwildfiredamageanddestructionrequiresimplementingmeasuresbeyondthoseinvolvinganindividualbuildingorparcel.Itisalsoessentialtoenhancemitigationmeasuresattheneighborhoodandcommunitylevels,whichwilleffectivelyexpandthezoneofprotectionbeyondtheindividualparcelorbuilding.

Thelocalfireagency,stateforestryornaturalresourcesdepartments,thelocaloffice•ofemergencymanagement,orotherlocalorganizationsshouldbecontactedtoobtaininformationaboutthehazardsandrisksinanarea.

Key Issues Emergencyresponsevehiclesmayneedtoaccessawildfireareaatthesametimeevacuation•trafficisleavingthearea.Firefightersneedsafeaccessalongroadstoreachthewildfireandaccesswaterresources.

Visiblestreetsignsandpropertyaddressesprovidefirefighterswithcriticalresponseand•locationinformation.Propertyaddressesareoftennotvisible,andaroadnamemayoccurmorethanonceinajurisdiction.

Wildlandfuelsandlandscapevegetationalongroadscanplacefirefightersinextremely•hazardoussituations.

Waterresourcesforwildfiresuppressionarevitalandneedtobeaccessible.•

Guidance for Roads and DrivewaysRoadsshouldbewideenoughtoallowevacuationandemergencyvehiclessimultaneous•access.Minimumwidthis20feetforaccessroadsand12feetfordriveways(seeFigure1).

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Themaximumgradeofroadsanddriveways•shouldbedeterminedbythelocaljurisdictionbutingeneralshouldnotexceedagradeof16percent.

Roadsanddrivewaysshouldprovide•sufficientverticalclearancetoallowfor largeemergencyvehicles.Theminimum is13.6feet(seeFigure1).

Roadsshouldsupportaminimum•of40,000poundstoallowforheavyemergencyvehicles.

Appropriatesignage,includingbutnot•limitedtoweightandverticalclearancelimitationsandone-wayroadandsingle-laneconditions,shouldbepostedandfullyvisibleonnoncombustiblesignsandposts.

Gatedaccessfromapublicroadwayshould•besetbackfromtheroadwayatadistancethatissufficienttoallowemergencyequipmenttoclearthetrafficlane.Adistanceof50feetshouldbeadequateformostequipment(seeFigure2).

Turnaroundsshouldbeattheendofroads•andondrivewaysthatarelongerthan150feet.Theminimuminsideturningradiusshouldnotbelessthan30feet,andtheoutsideturningradiusforaturnaroundshouldbe45feetfromthecenterlineoftheroad.Ifahammerhead/”T”isused,thetopofthe“T”shouldhaveaminimumlengthof60feet(seeFigure3).

Roadsanddrivewaysshouldprovide•all-weatheraccess,whichmayrequireasphaltorconcretesurfacing.

Address and Signage Publicandprivateroadsandstreetsshouldbeidentifiedbyanameornumberthrougha•consistentjurisdiction-widesystemthatprovidesforsequencedorpatternednumbering and/ornon-duplicatingnamingwithineachjurisdiction.

Figure 1.Roadwithadequatewidthforemergencyvehicles.

Figure 3. Thetopofthe“T”usedforaturnaround(AnchorPointGroup,Boulder,CO).

Figure 2.Gatedaccesswitha50-footsetbackthatallowsemergencyvehiclestoclearthetrafficlane.

13.6-footminimum clearance 20-foot minimum

width for access roads

12-foot minimum width for driveways

50 fe

et

FS No. 17 – Community Infrastructure Home Builder’s Guide to Construction in Wildfire Zones 09/08 Page 3 of 5

Sizeofletters,numbers,andsymbolsforstreetandroadsignsshouldhaveaminimum4-inch•letterheightand1/2-inchstroke,bereflective,andcontrastwiththebackgroundcolorofthesign.Thesignandsignsupportshouldbeconstructedofnoncombustiblematerials.

Streetandroadsignsshouldbevisibleandlegiblefrombothdirectionsofvehicletravelfora•distanceofatleast100feetandbemountedataheightof7feetfromtheroadsurfacetothebottomofthesign.

Allbuildingsshouldhaveapermanentlypostedaddressateachdrivewayentranceandshould•bevisiblefrombothdirectionsoftravelalongtheaccessroad.

FuelModificationReducingthevolumeanddensityof•combustiblevegetationreducestheintensityofwildfire.Strategicfuelmodificationalongaccessandegressroutesincreasessafetyforemergencyfireequipmentandevacuatingcitizens(seeFigure4).

Areassuchasgolfcourses,schools,•andlargeparkinglotsshouldbelabeledassafetyzonesforcitizensunabletoevacuateorforfirefighters.Itiscriticallyimportantthattheseareasbeevaluatedbyfireprofessionalsbeforeasafetyzoneisdesignated.

Guidance for Emergency Water Supply Community-widewatersuppliesneedtobeavailableandaccessible.•

Signsshouldbeprovidedindicatingaccesstoeachwatersource.•

Vegetationshouldbemaintainedateachwatersourcetoallowsafeaccesstothesource.•

Water Tanks and Pressure SystemsSomecommunitywatersystemsusetanksandcisternstostoreemergencywatersupplies.Individualpropertiesmaybesuppliedwithpotablewaterthroughon-sitewellsorlimiteddistributionsystemsduetothedispersednatureofthecommunityorthecostofinstallingamajorwaterdeliverysystem.Watertanksshouldbeconstructedofhighlyfire-resistantmaterialssuchassteel,concrete,or•ferrocement.Fiberglasstanksmaybeplacedunderground.Allcisternsorwatertanksusedfor

Figure 4.Exampleofamapdepictingareasforplannedfuelmodificationalongevacuationroutes/fireaccessroads(AnchorPointGroup,Boulder,CO).

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emergenciesshouldhaveafiredepartmentconnection.Thelocaljurisdictionmayspecifythesizeandtypeoffiredepartmentconnection.

Pressurizedsystemswithhydrantsshouldconformtothelocaljurisdiction’srequirementsor•recommendationsforspacing,flow,andpressure.

InstallationshouldmeetNationalFireProtectionAssociationstandardsattheminimum.•

Dry HydrantsManyruralareasdonothaveaccesstothepressurizedhydrantsthatarecommoninlargercommunitiesforfirefighting.Whenpressurizedsystemsarenotavailable,dryhydrantsarerecommended.Dryhydrantsarearelativelyinexpensivewaytoprovideareadysourceofwaterforfirefighting

Adryhydrantisanon-pressurizedpipesystemthatallowsfireequipmentaccesstoanearbysourceofwatersuchasalake,stream,pond,residentialpool,orcisternwithaminimumwaterdepthof2feet,orawatersourcesuchasatankthatisnotdirectlyaccessibletoafireapparatus(seeFigure5).

ConsiderationsThefire-suppressioncapabilitiesinthearea,asdiscussedabove,shouldbeconsideredwhenselectingaconstructionsite(seeFactSheet#3,SelectingtheConstructionSite).

Formoreinformationaboutinfrastructure,seeFEMA’sWildfireHazardMitigationHandbookforPublic Facilities.

EffectivenessTheeffectivenessoftherecommendedmeasuresvariessignificantly,dependingontheinfrastructureelementsthatarepresentinthecommunity.

Figure 5. Dryhydrantdesigns.

2-foot minimum

Anticipated low-water level

Normal waterline elevation

Installation below frost depth

18-footmaximum

2 feet

Strainer

Design using two 45-degree elbows

Design using two 90-degree elbows

FS No. 17 – Community Infrastructure Home Builder’s Guide to Construction in Wildfire Zones 09/08 Page 5 of 5

ResourcesCaliforniaAdministrativeCodeTitle14,Division1.5,§1270–1276.

InternationalCodeCouncil.2006.2006 International Wildland-Urban Interface Code.

NationalFireProtectionAssociation.2001.NFPA Standard 1142: Standard on Water Supplies for Suburban and Rural Fire Fighting.

NaturalResourcesConservationService.DryHydrantDesignDrawings.http://www.sc.nrcs.usda.gov/technical/dryhydrant.html.

Lagucki,T.andK.Mancl.FireProtectioninRuralAreas:DryHydrantsforPonds.TheOhioStateUniversityFactSheet:Food,AgriculturalandBiologicalEngineering.http://ohioline.osu.edu/aex-fact/0422.html.

RanchoSantaFe[California]FireProtectionDistrict.StandardforDriveways,Dead-EndsandLoopedAccessWays.http://www.rsf-fire.org/prevention/access_requirements.asp.Includesinformationonfireaccessroadandfirehydrantspecifications(specificationsandordinancesmaybedifferentforotherstates,cities,anddistricts).

StateofMinnesota.TheDryHydrantConcept.http://files.dnr.state.mn.us/assistance/backyard/firewise/dryhydrant_advantages.pdf.

Winter,A.,S.Holman,S.Kett,andR.Dolan.2006.Taylor[Florida]CommunityWildfireProtectionPlan. http://www.fl-dof.com/publications/fire_pdfs/taylor_fl_cwpp_complete.pdf.Includesimprovementstowildlandfireresponse,suchasinstallationofdryhydrantsandupgradestocommunicationsequipment.