rtrofitimprovements aking homes/media/files/... · • roof sheathing replacement • soffit...

RETROFIT Improvements Making Homes Safer in Disasters Hazards February 2012 Working Draft www.toolbase.org Purpose • To create a continuous load-path from the roof to the wall • To resist uplift forces from wind • To resist lateral forces from wind and earthquakes Benefits • Strengthens connections in wind and seismic events Retrofit Opportunity • Roof sheathing replacement • Soffit replacement • Residing Illustrations Retrofit Option 1: Hurricane clip connecting the truss or rafter to top plates. Summary In many homes built before 1990, roof trusses or rafters were fastened to the wall with two framing nails angled into the rafter and wall plate in what is known as a toe-nailed connection. The connection is inadequate to resist the force of high wind pushing up on the overhang and soffit (which can act like a sail to catch wind). In hurricane and gale wind conditions, roof structural supports have been pried away from the wall by the force of wind. Installing a stronger mechanical connection between the roof framing members and the wall will increase the capability of the roof structure to withstand the uplift forces from hurricane winds and lateral forces from earthquakes. Steel hardware, such as is often seen on outdoor decks, can provide the secure connection required between roof and wall framing. Tie down hardware, also known as hurricane clips, can be installed for under $10. A house sized 40’ x 30’ requires approximately 42 pieces, so providing added assurance with tie down hardware would cost between $200 and $400. This cost, however, assumes direct and simple access to the wall and roof framing, which is not often the case in a completed house. But, retrofitting roof tie down hardware becomes cost effective when included in the scope of other remodeling work such as residing, replacing soffit and fascia, or replacing roof sheathing at the overhang. Consult your contractor for the inclusion of this and other safety details that will add value and peace of mind to your planned home improvement projects. Roof-to-Wall Attachment Flood Wind Rain Seismic Snow Fire Option 2: Tie strap connecting the truss or rafter to the wall stud and top plates.

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Page 1: RTROFITImprovements aking Homes/media/Files/... · • Roof sheathing replacement • Soffit replacement • Residing Illustrations Retrofit Option 1: Hurricane clip connecting the

RETROFIT Improvements MakingHomesSafer inDisasters

Hazards

Februar y 2012 Working Draf t w w w.toolbase.org

Purpose•Tocreateacontinuousload-pathfromtherooftothewall

•Toresistupliftforcesfromwind•Toresistlateralforcesfromwindandearthquakes

Benefits•Strengthensconnectionsinwindandseismicevents

Retrofit Opportunity•Roofsheathingreplacement•Soffitreplacement•Residing

IllustrationsRetrofitOption 1:Hurricane clip connecting the truss or rafter to top plates.

SummaryInmanyhomesbuiltbefore1990,rooftrussesorrafterswerefastenedtothewallwithtwoframingnailsangledintotherafterandwallplateinwhatisknownasatoe-nailedconnection.Theconnectionisinadequatetoresisttheforceofhighwindpushingupontheoverhangandsoffit(whichcanactlikeasailtocatchwind).Inhurricaneandgalewindconditions,roofstructuralsupportshavebeenpriedawayfromthewallbytheforceofwind.Installingastrongermechanicalconnectionbetweentheroofframingmembersandthewallwillincreasethecapabilityoftheroofstructuretowithstandtheupliftforcesfromhurricanewindsandlateralforcesfromearthquakes.Steelhardware,suchasisoftenseenonoutdoordecks,canprovidethesecureconnectionrequiredbetweenroofandwallframing.Tiedownhardware,alsoknownashurricaneclips,canbeinstalledforunder$10.Ahousesized40’x30’requiresapproximately42pieces,soprovidingaddedassurancewithtiedownhardwarewouldcostbetween$200and$400.Thiscost,however,assumesdirectandsimpleaccesstothewallandroofframing,whichisnotoftenthecaseinacompletedhouse.But,retrofittingrooftiedownhardwarebecomescosteffectivewhenincludedinthescopeofotherremodelingworksuchasresiding,replacingsoffitandfascia,orreplacingroofsheathingattheoverhang.Consultyourcontractorfortheinclusionofthisandothersafetydetailsthatwilladdvalueandpeaceofmindtoyourplannedhomeimprovementprojects.

Roof-to-Wall AttachmentFloodWind Rain Seismic SnowFire

Option 2:Tie strap connecting the truss or rafter to the wall stud and top plates.

Page 2: RTROFITImprovements aking Homes/media/Files/... · • Roof sheathing replacement • Soffit replacement • Residing Illustrations Retrofit Option 1: Hurricane clip connecting the

Februar y 2012 Working Draf t w w w.toolbase.org

Potential Damage

Key Steps •Planthisretrofitasapartofalargerhomeimprovementprojecttomaximizecostefficiency,asaccesstothewallandroofframingintersection(frominsideoroutside)isnecessary.

• Inspecttheframingtoensureacontinuousloadpath.• Inspectforexistingtie-downhardwareanddetermineadditionalhardwarerequirements.• Installtie-downhardwarebeforeproceedingwithlargerproject.Hardwareinstallationwillrequireabouttwohours,soitshouldn’tmateriallyaffectthepaceoftheoverallproject.

•Yourcontractormayhaveadditionalideasonhowtoimprovethesafetyofyourhome.•Formoredetailsaboutthisretrofitimprovement,pleaserefertothelistofResourcesinthesectionbelow.

ResourcesFEMA,Home Builder’s Guide to Coastal Constructionhttp://www.fema.gov/library/viewRecord.do?id=2138

Photo:www.fema.gov

http://www.fema.gov/library/viewRecord.do?id=2138

http://www.fema.gov

Lead sheathing

Pat's Affordable Home Inspections14.Acceptable Roof Framing: 2x6 Rafter 15.Acceptable Sheathing: Plywood 16.Defective Ventilation: Ridge and soffit vents, Gable vents - Torn screens

OSNA -10 Copper-Nickel Sheathing on Offshore Structures · OSNA®-10 Copper-Nickel Sheathing on Offshore Structures ... Copper-nickel sheathing on offshore structures ... EEMUA 144-1987

Brochure - GlasRoc Sheathing - CertainTeed · PDF fileGlasRoc® Sheathing ®) CertainTeed

Cho soffit-brochure-rev

ELASTIC BEARING CONSTANTS FOR SHEATHING MATERIALS · sheathing materials and between sheathing materials and wood. 1 . Table 1. - Plywood panel constructions as obtained from measurement

continued) Soffit & Vertical Siding CertainTeed

SOFFIT - Insulation-Insulation