WOOD...Drawings/ Detailing by Robert Bateman A.I.A. At the end of this program,participants willbe ableto:At the end of this program, participants will be able to: 1. Recognize benefit

WOOD:WOOD:Detailing Best Practices:Detailing Best Practices:Air Barriers, Moisture,Control and Windows

Karl Kardel, PrincipalKarl Kardel Consultancyy

Drawings/ Detailing by Robert Bateman A.I.A.

At the end of this program, participants will be able to:At the end of this program, participants will be able to:

1. Recognize benefit of proper installation ofsheathing substrates2. Evaluate differences with wood trim. valuate differences with wood triminstallation, including back sealing or priming3 Select critical flashings water/air barriers3. Select critical flashings, water/air barriers4. Understand new window flashing options

© 2014 Karl Kardel Consultancy & The Wood Products Council© 2014 Karl Kardel Consultancy & The Wood Products Council

OutlineOutline

• HistoryHistory• Sheathing

i b i• Air barriers• Wall base• Roofs• TrimTrim

IntroductionIntroduction

• This talk utilizes the experience of inspections, restorationsand repairs to some 30,000 buildings ranging fromMichigan, to California, Oregon, Nevada, and Florida.

• Reviewing many years of ‘construction defects’ a smallnumber of issues keep reappearing, all avoidable. Manyare simple issues of human components or necessaryphysical work that are not considered by designers and

f t t th t l t f ilmanufacturers, yet they are central to failures.• At The Threshold of a New Era : AIR BARRIERS provide the

means to control air flow and leaks. Insulation can now beff ti A d i d bl d t ti t ideffective. And required blower door testing to providearchitects and developers verification of performance.

Premises of this talkPremises of this talk

• Current weather barriers are prone to common failures. Alittle water inside the wall damages or ruins the system.

• Current weather barriers rely on assumption of a drainageplane.

• The workers applying cladding or stucco wire and lathsystems work ‘opaque’ that is they cannot locate studsvisually under the membranes. Workers are blinded.

• Fasteners that miss studs create likely leaks.• Basic tool is the nail gun which attaches cladding and wire

lath tightly to walls. Our tests have shown commonly alath tightly to walls. Our tests have shown commonly arazor blade cannot be placed between layers.

• Thus the “membrane drainage wall” is an assumption.• Solutions overdue will be provided• Solutions overdue will be provided.

ContinuedContinued

• AIR BARRIERS allows insulation to function properly.p p yWithout control of air movement and leaks, insulationis a theoretical determination.I t i til ti h ld b hi d b i d d• Interior ventilation should be achieved by windows anddoors and air exchanges, not leaks and holes.

• Successfully installed AIR BARRIERS will achieve leakSuccessfully installed AIR BARRIERS will achieve leakfree durable buildings.

• But it will require extra care & discipline incoordination, commitment and skill with all tradesfrom framing, sheathing, and weather barriers that hasnot previously been achieved.not previously been achieved.

HistoryHistory

Same issues as of old: Exemplars ofSame issues as of old: Exemplars ofhistoric approaches:

Homes in England & US in the 18th and 19thHomes in England & US in the 18th and 19thCenturies also had muslin stretched out overwood plank base and sized with plaster towood plank base, and sized with plaster tokeep out drafts at interior walls.

1 Pleasant Hill Shaker Village Kentucky 1840’s1. Pleasant Hill, Shaker Village, Kentucky 1840 srubble and infilled walls for draft control andinsulation:

Rubble infill insulating walls 1840’sRubble infill insulating walls 1840 sEarly dimensional wood framing

f ll d h bbl b kinfilled with rubble & brick

Early air barrier solutions/ ads:Early air barrier solutions/ ads:

• From the 17th Century through the most of the 19thy gCentury draft and damp barriers were placed on thewall inside face.St ti i il i th l 20th C t h lt d• Starting primarily in the early 20th Century asphalt andother sheet goods moved to under the exteriorcladding. This continues today. Early plaster buildingsg y y p gin the Bay Area used cotton felt as an air barrier understucco. But with furred out stucco.

• From the 1920’s stucco in California was furred out• From the 1920’s stucco in California was furred outfrom the walls to keep the sheathing dry. This practiceshould be revisited.

States that Mandate Air BarriersStates that Mandate Air Barriers

Weather, draft sheets to block air, 1870’sWeather, draft sheets to block air, 1870 sPoint: Early barriers were as much for draughts

b i ( 1908)as water barriers (ca. 1908)

Water barrier for under siding by Bird & Co.(A 1891)(Aprox. 1891)

History (Cont’d)Modern Framing started here: Balloon

or dimensional framing/ Chicagoor dimensional framing/ ChicagoCARPENTRY MADE EASY, Science and Art of Framing(on balloon framing, published from 1858, redone in1875 th h 1904)1875, through 1904)

The author recommends using plaster furred out on theinside to achieve ‘almost air tight’ lining. He advisesg git is not possible to keep water out of a wood sidedbuilding.

Thus a 150 years of designers and builders seekingsolutions, we are at an epical time for solutions.

Repairs to steel framed buildingsRepairs to steel framed buildings l h d fRunning along the SF Bay dozens ofnew buildings are failingg g

• Most are steel stud walls.• Steel studs have some near intractable problems: Thermal Bridging;

Condensation causing corrosion due to air leaks, and minor leakageof water Water is recycled on and off studsof water. Water is recycled on and off studs.

• Older steel stud buildings have mildew mapped stucco at studlocations.

• Fasteners tend to ‘chew up’ fragile gypsum sheathing• Fasteners tend to chew up fragile gypsum sheathing• Scaffolding blocks direct tool access resulting in poor and broken

attachments.• SAF does not adhere well to sheathing due to lack of priming andSAF does not adhere well to sheathing due to lack of priming and

knurling of material for adhesion. Trades and designers are notinformed of fragility of SAF.

Today’s ChallengesToday s Challenges

• New untested Air Barriermaterials (Seee u tested a e ate a s (SeeReading List)

• Disconnect between manufacturers andk ’ k llworkers’ skills

• Disconnect between Architect's andk ’ killworkers’ skills

• Workers use air guns which have nosensory hand tool feedback They cannotsensory hand tool feedback. They cannotsee or feel stud location. Black paper‘blinds the wall ’blinds the wall.

4 Areas of typical failures4 Areas of typical failures

1. ROOF TOWALLS, and walls acting like roofs. Roof edgesare about 1% of costs, but over 50% of leak failures.[Building Design + Construction. Feb 2014] AIA continuingeducation.]

• Anything that is not vertical treat as a roof. Publishedstandards are inadequate. NRCA lists nosing minimum ofonly 1” for copings. Is that reasonable?

• Do not use a wall as a drain, walls will rot out. Do notallow any roof water flow down walls. Use gutters anddrains.

• NRCA specifies 1” roof edge nosing as adequate. Is anyroof edge dead level? This is not a sound standard, but stillheld to.

Garbage bagfi ?roofing?

The next trendin the Idiots

guide to roofingguide to roofing.True story.

WallProjection

Flashtransitions

junctures walljunctures wallto roof

Roof Edgeflash roof to

wallwallContinuity off broof barrier to

wall barrier

Roof EdgegMetal

flashing canflashing canbridge gapsat end ofsheathingsheathingand framing

ll l ftnormally leftto be 90

Roof EdgeContinuityof roof

barrier andwall barrierwall barrierconsider >1”lap of metaledge flashingedge flashingover walljoint

Item # 2 typical failures, sheathingd lgaps and sloppy construction

• Nails missing studs. Porcupine like inside of walls cansquirt water under air pressure in storms.

• Gaps at corners, sheathing too small or too big• Gaps to studs around windows• Gaps to studs around windows• Failure to block all joints• Membranes are subject to rips and tears that arej p‘tented’ or ‘floated’ over gaps

Note: Sheathing is the armature for the weather barrier.If not perfectly done an air barrier system is not possibleIf not perfectly done, an air barrier system is not possible.Critical: Inspect interior wall faces before finishes tocorrect all ‘shiners.’ Holes in sheathing will undercut AIRBARRIERSBARRIERS.

SheathingProtect

bottom edge ofbottom edge of– Non P. T.

d b dwood basedsheathings atwall base

h hSheathingAlign edgesAlign edgesof sheathingwith edges of

framingframing

SheathingKeep planeof sheathingof sheathing

aligneddaround

criticalwindow &

doordooropenings

Sheathing demands on designersSheathing demands on designers

• Sheathing is the armature for a finished wallSheathing is the armature for a finished wallcladding and the critical air and weatherbarrier betweenbarrier between.

• Trades are reluctant and will fight the neededstandards Drawings must show standardsstandards. Drawings must show standardsexpected, along with certainty of inspections.P l d h hi ill k i i ibl• Poorly done sheathing will make it impossiblefor an air & weather barrier to function.

What’s wrong with this picture? Always verify constructability ofd b lindustry submittals

Lath Industry photo, Note side to side bigli h dstapling nowhere near studs Numerous errors in applicationNumerous errors in application

Sheathing solution: ‘Rain Screen’Sheathing solution: Rain Screen

• Provides full unobstructed drainageProvides full unobstructed drainage• Provides pressure equalization

id h il idi d l h• Provides where to nail siding and stucco lath,ends shiners and air penetrations

• ALL claddings from dimensional siding toplaster should be placed over furring.

CA‘RainScreen’fromthe1920’s

Example‘R i ’‘Rainscreen’Continuity ofydrainage path

and airand airchannelsVented wall

basebase

Example‘R i ’‘Rainscreen’Continuity ofydrainage path

and air channelsand air channelsVented top of

wall

Example‘Rainscreen’

OutsideOutsidecornerdi icondition

Failure Areas: #3 Trim and flashingFailure Areas: #3 Trim and flashing

• Robust back priming of back side butt ends ofRobust back priming of back side, butt ends oftrim (& siding). Critical for decay resistance,sealant adhesion. ALWAYS BACKPRIME

• Flashing to divert water at trim/ window heads.SAF should always be applied to buried metalSAF should always be applied to buried metalflashing to prevent corrosion from condensation.

• Moist air in wood & wood windows will corrodeMoist air in wood & wood windows will corrodefasteners. Rust feeds iron fixating bacteria.

• Failure to slope and drain trim (see drawings)Failure to slope and drain trim. (see drawings)

b dd dEmbeddedtrimalwaysalwaysleaksStains toWRB fromtrim joint

Head TrimMetal headflashingflashingoptions:T f t iTop of trimTop ofp

windowextendedextendedover jambtrim joint

Sill TrimSill TrimSlope top ofhorizontal

trimtrimCap top ofll l ddiwall cladding

Jamb TrimOptions for

trim:trim:Lap trim 1piece

Cap trim 2Cap trim 2piece

Openingp gTrim

M th d fMethod oftrim lappingpp gwall claddingi linto slot

Outside CornerTrimTrim

Caution:h hThis is the

typical currentdetail common

to manyycladding manf.It is easy to doIt is easy to do,but relies onl t t bl ksealant to block

water entry

OutsideCorner TrimCorner TrimThis is thetraditionalmethod ofmethod ofprotecting

fedge of wallcladding andglapping jointmaintenancemaintenance

free

OutsideCorner TrimCorner TrimAlternate

method fortrim to laptrim to lap

wall cladding

Outside CornerTrim

Alternatemethodprovides aprovides amore

maintainablemaintainablesealant jointd k iand keeps trim

flush with wallfinish

Failure Area # 4: Windows andllInstallation

• Current rise construction has the weather barrieron the outside of the wall. Previously inside ofthe wall.

• Nails into the r o or gaps in SAF or flashing allow• Nails into the r.o. or gaps in SAF or flashing allowair (& water to pump inside) with wind

• Minor window product failures are fatal. Water isMinor window product failures are fatal. Water istrapped in the wall.

• Solutions: Waterproof the r.o. sill and add an aird h i id f h j b d h ddam or stop at the inside of the jamb and head.

• This will partially pressure equalize the openingand stop leaksand stop leaks.

Window SolutionWindow Solution

• We have manufactured metal pan frames inWe have manufactured metal pan frames ing.s.m.; stainless steel and copper to rehabfailed windows and openings.

• Suggestion: Look into full g.s.m. pans (seeASTM E2112 07.) Take over the wall opening.In 28 ga. metal it appears a completeinstallation flashing will run from $40 $60.00.( d i f ll ) E d h i SAF(see drawings to follow). End the practice SAForigami flashings.

Panning frames for aluminum windows*C b d f bl k f d il*Can be used for block frame and nail

fin typesyp

Wrap around 4 sided panning frameWrap around 4 sided panning frame

Example:Metalinsertinsertpanfl hflashing

Providesfull sillfull silldrainage& air& airdam on 4sidessides

SUMMARYSUMMARY

• Current weather barrier systems fail whenCurrent weather barrier systems fail whenstressed with more than incidental waterbehind cladding.

• Workers have no accurate idea where toattach with fastening.

• Nails and screws make holes and leaks.• Designers must take charge of inner wallDesigners must take charge of inner walldesign to meet future and current air barrierstandards. Default should not be to mfrs.

FUTUREFUTURE• FUTURE: Framers must have much higher skills in producing walls.

F h ld t i i ti it i d i d ftFramers should expect rigorous inspection criteria during and after.• FUTURE: Designers must manage profiles of inner wall to allow

weather barrier to remain intact.• FUTURE: Install furring over stud lines to direct air and water and• FUTURE: Install furring over stud lines to direct air and water and

prevent ‘shiners.’• FUTURE: Consider insert panning for windows to provide air barrier

and leak free rough opening.and leak free rough opening.• FUTURE: We can expect quantifiable expectations for building

construction with testing required.• ‘Back to the Future’ lessons learned historically can be part of oury p

progress. Today with wood framed buildings we can finally meet a150 years of expectations.

RECOMMENDED READING:

• “Carpentry Made Easy, Science And Art of Framing,” Williamp y y, g,E. Bell 1875 (first published 1854, and in print until 1908. Nowreprinted). Insights abound how to handle balloon (modern)framing including precursors to metal supportsframing including precursors to metal supports.

• “WOOD: Detailing for Performance.” William Dost, ElmerBotsai, 1990, GRDA Publications

• Perhaps the best successor to William Bell in ‘how to build.’Currently under revision by Karl Kardel, Robert Bateman &Kevin Flynn Chapters on open framing will be dropped woodKevin Flynn. Chapters on open framing will be dropped, woodpreservatives, coatings and windows will be updated. Newessays on sheathing and trim to be added. *Coming soon*

• “Stucco Wall Caps: Guide for Flashing Details” RobertBateman, 2011 www.Westcon.org

Reading ContinuedReading Continued• “Wood Decking Bulletin” Western Roofing Nov/Dec. 2009.

Thoughtful article on water problems with sheathingThoughtful article on water problems with sheathing,particularly OSB and management issues during construction.

• “The Perimeter Roof Edge” Drew Ballensky. Building Design+Construction Feb. 2014. AIA continuing education. (ShowsRoof edges account for over 40% of claims, versus 1% of costs)

• Three Articles on Air Barriers and Membranes A must reviewThree Articles on Air Barriers and Membranes. A must reviewfor designers on Air Barrier membranes:

• 1. “Analyzing self adhering underlayments” Mark S. GrahamNovember 2006 www.professionalroofing.net (note: only 2 of12 systems passed ASTM D1970. Only 2 passed ‘sealabilityaround nails.’ Karl Kardel feels designers should not assumegthis is reliable and fasteners should be sealed or lapped overinstead)

ContinuedContinued

• 2. “Testing Fluid Applied Air and Waterbarriers” Katherin WissinkPE, Laura R. Kellet, Steven S. Ruggerio, PE. SGH. ConstructionSpecifier Dec. 2012. (Fairly dismal results on most products tested.Article reviews products and standards. Projects should havep jtesting done on ‘buried membranes’ to verify and assess futureperformance, before construction.)

• 3 “Continuing Problems With Air Barrier” Dec 2011 Joshua Kelly• 3. Continuing Problems With Air Barrier Dec. 2011 Joshua Kelly,Jeffry J. Ceruti, PE. Construction Specifier. (A vivid and extensivedescription of Air Barrier Failures. Skepticism towards newproducts Article shows the need to design to provide for air barrierproducts. Article shows the need to design to provide for air barrierperformance.)

• USDA, various articles on Wood Decay, Coatings, and Species andf l b f l b h ’study of large number of military bases in the 1950 60’s.

Information is relevant today.

Karl Kardel Consultancyy479 Mountain AvenuePiedmont CaliforniaPiedmont, California

[email protected]• Waterproofing• Restoration• Window Diagnostics• Architectural Metals• Historic Preservation• Coatings/ Membranes• Building Envelope Forensics• Building Envelope Forensics