WoodWorks'Seminar'

Building Science and Moisture Control in Wood-frame Building Enclosures in the Pacific Northwest'

Michael(Aoki,Kramer(Principal(RDH(Building(Sciences,(Inc.(

Sea?le,(WA:((31(October(2012((

Portland,(OR:(1(November(2012((

“The Wood Products Council” is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. ""Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

Copyright Materials!"

This presentation is protected by US and International Copyright laws. Reproduction,

distribution, display and use of the presentation without written permission of the speaker is

prohibited.""

© The Wood Products Council 2012"

Learning Objectives!

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

�1)  Understand the fundamentals of building science for wood-frame

building enclosures 2)  Evaluate the difference between the form and function of air and

vapor barriers. 3)  Compare the performance characteristics of the three primary

types of wood-frame building enclosure assemblies: face sealed, concealed barrier, and rainscreen wall assemblies.

4)  Understand how to use the tools available to evaluate and select building enclosure assemblies how they can be used

"  Design(Approach:(Review(FuncMons(of(the(Building(Enclosure(and(how(prioriMes(have(changed(over(Mme,(i.e.,(goals(of(old(buildings(vs.(new.(

"  Review(Building(Enclosure(PrioriMes(for(Integrated(Facades(and(building(enclosure(design(based(on:(•  Exposure(CondiMons(•  ConMnuity(of(CriMcal(Barriers(–(air/water/thermal(•  Exterior(and(Interior(Environmental(CondiMons(•  Choice(of(Materials(and(Assemblies(

"  Review(of(analyMcal(tools(and(tesMng(procedures(and(the(importance(of(using(them(to(achieve(the(desired(end(result.(

"  Global(Context(

Overview'“There(is(no(more(sustainable(a(building(than(a(durable(one.”(

"  Nature(is(lazy.((Entropy(–(2nd(Law(of(Thermodynamics(–(heat,(air,(and(moisture)(

"  Find(the(path(of(least(resistance.("  Gravity(is(free.("  Slope(to(drain.("  Flashings(are(your(friends.("  It(costs(three((to(fi_een)(Mmes(more(to(fix(it(later.(

Building'Science'Fundamentals ((

Design'Approach'–'The'Building'Enclosure'

"   Sustainable(Building(or(Integrated(Design(or(not,(the(approach(is(the(same(

"   The(building(enclosure(sMll(needs(to(perform(the(same(funcMons("   Support((Structure,(People,(FuncMon/Purpose,(etc.)("  Control((Heat,(Air,(Moisture,(Light,(Fire,(Sound,(etc.)("  Distribute((Loads(–(structure,(interior(&(exterior(climate,(etc.)("   Finish((AestheMcs,(Durability,(Maintainability,(Renewal,(etc.)(

"  More(emphasis(on(thermal(performance(and(visible(light(transmission("  U,values((real/actual(vs.(tabular/assumed)("  Air(leakage("  Glazing(performance(

"  What(is(the(difference(between(buildings(we(build(today(and(those(we(built(80+(years(ago?("   Building(Materials?(–(More(moisture(sensiMve("   InsulaMon(levels?(–(How(much?(Too(much?("   Air(Mghtness?(–(How(Mght?((VenMlaMon?("   Speed(of(construcMon?((Time(is(money.("   Consumer(expectaMons?((Increasing.("   Lawyers?((ProtecMng(consumers(rights!(

Design'Approach:'Older'Buildings'

Design'Approach:'Older'Buildings'

"   CombinaMon(of(Fundamental(Differences("   Quality(of(detailing("   Quan/ty(of(insula/on("   Exposure(condi/ons((macro(and(micro)("  Wall(assemblies(more(tolerant(of(moisture("   Purpose(of(Buildings(

Design'Approach:'Older'Buildings'

"   (My)(Primary(ConsideraMon:(Rain(PenetraMon(Control("   Overhangs,(simple(architecture,(simple(rules.((More(complicated(=(

more(details(and(chance(for(water(entry.((We(can(handle(if(needed.("   2(stage(control(for(wall(systems(

•  cladding((water(shedding(surface)(•  Weather(resisMve(barrier((WRB)(is(last(line(of(defense(

"  Weather(ResisMve(Barrier("   Air(Barrier("   Flashing(at(penetraMons,(especially(window(openings("  Window(SelecMon(–(water(penetraMon(resistance,(thermal(

performance,(etc.(

Design'Approach:'Present'Day'Design'ConsideraCons'

"   CombinaMon(of(Fundamental(differences("   Complexity(of(building(form((more(details(–(more((headaches)(

Design'Approach:'Modern'Buildings'

Exposure'–'Macro/Micro'Climate'

0

0.1

0.2

0.3

0.5

0.4

A- Adjacent buildings of equal or greater height located within one building height in all directions

B- Many large buildings within 2 building heights

C- Rural areas, moderately treed, or buildings mostly fewer than 4 stories within 5 Building heights

D- Building located within 1km of direct waterfront exposure, or small or few surrounding obstructions, or located on a hill or cliff overlooking adjacent buildings

Overhang Ratio

Exposure Category

Terrain

Overhang Ratio = Overhang Width Wall Height

Where: Wall Height is the height above the lowest affected element (sill of window if considering a window)

Overhang Width is the horizontal distance between the outer surface of the cladding or window and the outer surface of the overhang

Concealed((Barrier(

Two(lines(of(defense(Some(drainage(possibiliMes(

ConCnuum'of'Strategies'for'Framed'Walls'

Barrier(or((Face(Sealed(

One(line(of(defense(

Drained((Cavity(

Two(lines(of(defense(Clear(drainage(

Rainscreen(

Two(lines(of(defense(Clear(drainage(Good(air(barrier(

Two(lines(of(defense(Clear(drainage(Good(air(barrier(CompartmentalizaMon(

P.(M.((Rainscreen(

Opportunity(for(Drainage(and(VenMlaMon(Drying(

Faith,based(Moisture(Control(

Design'Approach'–'High'Performance'Buildings''

"  More(than(just(adding(insulaMon("   High(Performance(=(Highly(SensiMve("   SensiMve(to(what?("  MOISTURE(

Hybrid(Cavity(&(Exterior(Insulated(Wall((

What(happens(when(we(fill(the(cavity(with(insulaMon(to(improve(thermal(performance?(

Design'PrioriCes'

Hybrid(Insulated(Wall((

( "   PotenMal(dew(point(problem.(Can(use(mathemaMcal(model(to(solve(and(provide(appropriate(balance(of(insulaMon.(

"  WSEC(prescripMvely(allows(1/3:2/3((inboard:outboard)(insulaMon(split(of(vapor(retarder(

"   Can(also(use(a(vapor(permeable(WRB(“membrane”(–(Typically(these(are(liquid(applied(products.(

"  Monitor(full(scale(performance(

Design'PrioriCes' Energy'Efficient'Rainscreen'Window'Sill'Detail'

Air'Barriers'

"   This(is(not(something(new…actually(just(recently(new(to(WA(State(Energy(Code(

"   Absolute(requirement(in(any(high,performance(building("   Lack(of(air,Mghtness….(

"  Direct(space(condiMoning(energy(loss("  PotenMal(for(condensaMon,(especially(in(highly(insulated(

assemblies("  Uncontrolled(IAQ(and(venMlaMon("  Unable(to(effecMvely(integrate(HRV(

Applicable Bldg. Code ; Number of Stories

2009 WSEC Section 502.4.5

2009 WSEC Section 1314.6.2

2009 SEC Section 1314.6.2

IRC X (pass) IBC Res; <5 stories IBC Res; >5 stories X (pass) X (pass or

report) IBC Non-res; <5 stories

X (pass or report)

IBC Non-res; >5 stories

X (pass) X (pass or report)

Energy Code Air Barrier Testing Matrix: WSEC vs. SEC

20 of Total

"   LOOPHOLES – MURBs & Non-res 5 stories or less "   5 story mixed use, 1 level non-res, 4 levels res = no

test, except in Seattle test only non-res portion per Chapt. 13

"   6 story mixed use, 1 level non-res, 5 levels res = test whole building per Chapt. 13

Any'piKalls'to'air'Cght'buildings?'

"   CondensaMon?("   IAQ(problems?("   HVAC(designer(assumpMons?(

(

"   There(is(more(to(it(than(just(making(the(building(more(airMght…("  RDH(Study(of(Performance(Monitoring(of(Wall(Assemblies(2004("  RDH(Study(of(Architectural,(HVAC,(Building(Enclosure(and(

Occupant(InteracMon(,(2005(

Do'Rainscreen'Walls'with'Air'Barriers'Work'?'

!Building(5(Building(4(Building(3(??(Building(2(Building(1(

2003(,(Percent(of(Time(Moisture(Reading(in(Exterior(Sheathing(is(in(Yellow(or(Red(Category((i.e.(wet)(

YES( NO(??( YES(YES( YES(

Building'3'–'RH'in'Stud'Cavity'

Rainy(Season(–(October,May(

Abnormally'High'Interior'RelaCve'Humidity'

100%(,(CondensaMon(

Modeling'can'Predict'Problems'

RelaMve(Humidity(,(@(DensGlass(

Temperature(of(DensGlass(

"   Vapor(Retarder(Paint,(Improved(Air,Mghtness(+(Improved(Suite(VenMlaMon(

Modeling'Can'Also'Predict'Performance'of'Repair' Why'measure'air'leakage/test'air'barrier?'

"   Confirm(performance((meet(guideline(or(code(requirement)("  Key(for(high,performance(buildings(

Achievable Construction

Testing & Calibration

Design Assumption & Modeling

Various'Standard'AB'Test'Results'In'Equivalent'Units'

Standard'' Equivalent'AirSLeakage'Area'NaConal'Building'Code'of'Canada(

2005,(for(assemblies(((i.e.(window/curtain(wall)(

0.15(L/s/m2(@(75(Pa(=(0.23'cm2/m2'@'50'Pa'

ASHRAE(–(Mght(exterior(enclosure( 0.1(cfm/_2(@(75(Pa(=(0.7'cm2/m2'@'50'Pa'

Air'Tightness'TesCng'and'Measurement'AssociaCon((ATTMA(2007),(“best(pracMce”(dwelling(enclosure(air,Mghtness(with(mechanical(venMlaMon(

3.0(m3/hr/m2(@50(Pa(=((1.5'cm2/m2'@'50'Pa'

LEED'v2.2(for(New(ConstrucMon(–((EQ2(Pre,requisite(2:(Tobacco(Smoke(Control),(Test(of(all(6(sides(of(an(apartment(

1.25(in2(EfLA(@(4Pa/100(_2(=(2.1cm2/m2'@50Pa'

ASHRAE(–(average(exterior(enclosure( 0.3(cfm/_2(@(75(Pa(=(2.1'cm2/m2'@'50'Pa'2009'WSEC'and'InternaConal'Energy'

ConservaCon'Code((IEEC),(Opaque(Enclosure(Leakage(

0.4(cfm/_2(@(75(Pa(=(2.9'cm2/m2'@'50'Pa'

ASHRAE(–(leaky(exterior(enclosure((( 0.6(cfm/_2(@(75(Pa(=(4.3'cm2/m2'@'50'Pa'

LEAK

IER'

TIGH

TER'

Air'Barrier'Performance'TesCng'

"   Air(Leakage(is(Important(to(Space,Heat(Energy(Loss("  Once(air,leakage(is(addressed,(conducMve(losses(become(

increasingly(important(

(

Impact'of'Whole'Building'AirSCghtness' Thermal'Anatomy'in'“AirCght”'Buildings'

"   R,12(InsulaMon(in(steel,stud(walls("  R,5(accounMng(for(steel(studs(

"   R,20(Roof(InsulaMon("   R,1.8(Windows,(60%(Wall(Area(

"  Aluminum(window(wall,((hard,coat(low,e,(air(fill(

U,overall(=(1/5(*(0.38(+(1/20(*(0.06(+(1/1.8'*'0.56'

(((((='0.39(((((,,>(RSoverall'=2.6''''80%'Heat'Loss'through'windows'

240(suites,(180,000(sq._.(Envelope(area(=(38%(walls,(6%(roof,(56%(windows(RS4'windows'instead'of'RS1.8'improves'overall'RSvalue'to'RS4.5,'an'overall'improvement'of'RS1.9'(73%)'

High'Rise'RSValues'–'are'they'where'they'should'be?'

3K(sq._.(house(20%(

window/wall(

DOE(Future(

"   Nominal(InsulaMon(R,values(are(not(effecMve(R,values(due(to(thermal(bridging(

"   Steel(studs(reduce(the(effecMve(R,value(of(the(insulaMon(by(50,60%(

"   An(addiMonal(30,40%(reducMon(occurs(at(the(slab(edge(and(shelf(angle(

"   An(R,12(fibreglass(ba?(insulated(wall(becomes(R,3(to(R,4(effecMve((compared(to(R,2(with(empty(cavity)(

"   Add(insulaMon(to(the(exterior(to(cover(over(studs(and(slab(edge(

"   Support(shelf(angle(on(brackets,(with(insulaMon(behind(angle(

Steel'Stud'Wall'Assemblies'

"   EffecMve(R,values(due(to(thermal(bridging(are(even(less(than(we(think(because(of(actual(amount(of(framing(versus(assumed(amount(of(framing(

"   Wall(in(photo(has(70%((((((((((((((((((((framing(area(versus(10%(for(((((((((((((((((((((((((((((walls(with(studs(at(16”(o.c.(

"   Even(with(2(inches(of(addiMonal(exterior(insulaMon,(wall(R,value(is(about(R11(versus(the(ASHRAE(90.1(value(of(R,19.6(for(studs(at(16”(o.c.(

Steel'Stud'Wall'Assemblies'

"   ConMnuous(metal(Z,girts(de,bridge(insulaMon(similar(to(studs(by(50,60%(reducMon(BUT(slab(edge(is(covered(

"   R,15(insulaMon(becomes(<R,7.5,(be?er(than(insulaMon(within(studs,(but(sMll(not(good,enough(

Exterior'Insulated'Wall'Assemblies'

Wood'Assemblies'

"   Light(Frame(ConstrucMon(–(Primarily(residenMal,(light(commerical("   Heavy(Timber(ConstrucMon(–(Primarily(commercial,(not(pracMced(

regularly(except(for(religious(sanctuaries(and(sustainable(office(buildings((same(thing?)(

"   Moisture(Storage(Capacity(–(double,edged(sword("   Thermal(Performance(–(Be?er(overall(R,value(compared(to(all(other(

structural(materials(used(to(construct(buildings("   High(Rise(Examples/CLT(–(Not(just(for(SF(homes(anymore(.(.(.(

"   Remember(exposure(condiMons("   Design(enclosure(assemblies(appropriate(for(exposure(

"   Intermi?ent(cladding(supports(are(significantly(more(thermally(efficient(than(conMnuous(girts.((

"   InsulaMon(R,value(reducMons(of(15,30%(with(clips.(("   “Clips”(are(necessary(in(to(achieve(high(R,values("   Development(of(clips(with(low,conducMvity(

(fiberglass,(stainless(steel)(

Intermikent'Cladding'Support'

"   Concrete(balconies(and(eyebrows(are(effecMvely(un,insulated(<R,1(protrusions(through(the(insulated(wall((

"   An(exposed(slab(edge,(reduces(effecMve(wall(R,value(by(approximately(35%.(

"   A(balcony(or(eyebrow(protrusion(reduces(effecMve(wall(R,value(by(approximately(40%(

"   “High,performance”(is(not(possible(with(these(features,(as(typically(constructed(

Concrete'Balconies'&'Eyebrows' Does'This'Meet'Green'Building'ObjecCves?'

~R,2.6((U,0.39)(Aluminum(windows(–(60%(

~R,10(spandrels(–(15%(

~R,15(brick/clad(walls(–(15%(

<R,1(exposed(concrete(balconies(–(8%(

Overall'~RS2.9'

"  What(is(the(“right”(relaMve(humidity?((25%,60%((ASHRAE(62,2001)("  Measured(where?((Avoid(70%(RH(at(surfaces("  70%(RH(minimum(necessary(to(support(mold,(dust(mite,(but(

temperature(dependent(

"   RelaMve(Humidity,(Surface(Humidity,(and(CondensaMon("  70°F,(40%RH(=(45°F(dew(point(

•  Surface(Humidity(=(70%(RH(@(54°F(=(microbial(growth(

"  70°F,(25%RH(=(32°F(dew(point(•  Surface(Humidity(=(70%(RH(@(40°F(=(no(microbial(growth(

"  Where(RH(near(surfaces(is(below(70%,(microbial(growth(is(controlled;(therefore(in(order(to(control(microbial(growth,(one(must(also(control(temperature(and(vapor(pressure(near(surfaces.(

RelaCve'Humidity'and'the'Building'Envelope'

30%(RH(

80%(RH(

Balancing'Act:'Understanding'System'InteracCon'

Performance'CharacterisCcs'"   AirMght(building(shell(≤(0.6(ACH(@(50(pascal(pressure,(

measured(by(blower,door(test.("   Annual(heat(requirement(≤(15(kWh/m2/year("   Primary(Energy(≤(120(kWh/m2/year(In(addiMon,(the(following(are(recommendaMons,(varying(with(

climate:("  Window(u,value(≤(0.14((R,7)("   VenMlaMon(system(with(heat(recovery(with(≥(75%(efficiency(

with(low(electric(consumpMon(@((0.45(Wh/m3(

"   Thermal(Bridge(Free(ConstrucMon(≤(0.01(W/mK(

Passive'Haus'Design' Passiv'Haus'–'What'does'it'look'like?'

"  HVAC systems are the primary tool we have for controlling the interior environment "  Acceptable air quality, temperature and humidity

"   Performance is impacted by: "  Architectural layout and interior design "  Building envelope "  Occupants/Owners "  Climate

"  Consideration of all of these factors determines what are ‘reasonable’ and Good, Better, and Best practices

Tie it all together . . . Summary of High Performance Building Attributes

"  Window/glazing(thermal(performance(–(key(to(achieving(high,performance,(integrated(façade(design(

"   2,D/3,D(Thermal(analysis(of(building(enclosure(assemblies(to(understand(“real(R,value”(

"   Air(Barrier(–(A(Must("  Understand(interior(design(condiMons,(HVAC(operaMng(

assumpMons,(manual(and/or(automaMc(control(points("   Evaluate(building(enclosure(“hygrothermal”(performance(

"   Hygrothermal(SimulaMons(can(help(to(further(refine(thermal(analysis(and(assess(risks(of(various(alternaMve(assemblies(and(design(condiMons.(

"   Test/commission(the(enclosure(and(HVAC(system(

Designing'Today'For'Tomorrow:'The'Opportunity'of'the'21st'Century'

"  Climate(Change,(Energy(ProducMon,(Electricity(Usage(

" SuperinsulaMon,(Passive(Design,(A?enMon(to(Detail,(Building(Science(

Climate'Change'–'What'will'it'take'to'get'“there”'

Climate'Change'–'What'does'“there”'look'like?' Climate'Change'–'it’s'here'

Climate'Change'and'Petroleum'–'Peak'Oil' Climate'Change'and'Energy'ProducCon/ConsumpCon'

Climate'Change'and'Energy'ProducCon/ConsumpCon'

Total Energy

Electricity

The'Opportunity'of'the'21st'Century'

Can'we'do'it?''We’ve'done'it'before.'

1.  Admit(that(we(have(a(problem:(water,(air,(physics,(gravity,(CO2,(.(.(.(2.  Don’t(forget(the(2nd(Law(of(Thermodynamics!(3.  Be(wary(of(products(that(defy(the(laws(of(physics(4.  Design(and(construcMon(of(the(building(enclosure(is(a(risk(management(

exercise(–(presently(and(for(future(generaMons(5.  Design(assemblies(and(details(to(suit(macro(and(micro(exposure(condiMons(6.  Air(Barrier/air(control(layer(conMnuity(is(‘criMcal’(7.  Water(ResisMve(Barrier/moisture(control(layer(conMnuity(is(‘criMcal’(8.  Water(Shedding(Surface(conMnuity(is(‘criMcal’(–(holes(with(laps(are(OK(9.  Vapor(Barrier(conMnuity(is(nice(but(not(usually(criMcal(and(should(be(evaluated(

on(project(specific(basis(10.  Controlling(microbial(growth(requires(controlling(surface(temperature(and(

vapor(pressure(and(reliable/funcMonal/controllable(mechanical(systems(11.  Adaptable,(Redundant,(and(Maintainable(=(Durable(and(Sustainable(12.  Get(engaged,(be(aware(13.  Seek(the(help(of(your(favorite(building(science(consultant(

12'Step'Program'to'Solve'the'World’s'“Issues”'

Final Thoughts

How do we love all of the children all of the time. - William McDonough

Questions?

This concludes The American Institute of Architects Continuing Education Systems Course

Michael Aoki-Kramer RDH Building Sciences maokikramer@rdhbe.com