Today’s Trends in Air Barriers - · PDF fileToday’s Trends in Air Barriers ... driven by pressure and temperature ... air is the most significant vehicle in eliminating

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Today’s Trends in Air Barriers

• Fred Kramer, Building Envelope Solutions Team

• Marcy Tyler Technical Applications Manager• Marcy Tyler, Technical Applications Manager

A conservative estimate of building envelope failure is 3-5%

Building Envelopes Today

• N.A. building envelope repair is a multi-billion dollar industry.

• Most problems are moisture-related, caused by air or moisture leakage.

• Most façade problems relate to terminations d ti d t il

© 2008 Tremco Inc.

and connection details.

• 70% of all construction litigation is related to façade leakage.

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90% of the time, it comes down to the transitions and terminations

A f il i t d d ff t th

What Causes Building Envelope Failure?

A failure in one component can and does affect other components in the building

© 2008 Tremco Inc.

The Evolution &&

Building Science Of

Air BarriersAir Barriers

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Premature Deterioration Of 1970- 1980’s Led To Adoption Of Air Barrier Codes

Northern Climates Were Prone To Greater Deterioration

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The Uncontrolled Escape Of Warm Interior Air To The Exterior Was The Issue

Lack Of Continuity Of The Envelope Played The Major Role In The Damage

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Window, Roof, Soffit Intersects All Proved To Be Trouble Areas

Older Buildings May Not Have Leaked Water, But They Leaked Air!

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In Some Cases Severe Air Leakage lead to Complete Re-Cladding

Past Building Practices Focused More On Water Shed Versus

Continuous Air Seal

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Energy Loss And Wall Damage Were Caused By Air Leakage

Poor Quality Mortar Joints Added To The Outbound Air Flow

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Assembly Transitions Lacked Durable Air Seals

Seals Were Not Made Around Penetrations

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Excess Mortar Prevented Drainage Of The Cavity Wall

Evolution Of The Air Barrier

These Older, Deficient Building Practices

And

A Federal Mandates For Energy Efficient Buildings….. Various Energy Acts 2005 to 2009g gy

Created A Demand For Air Barriers.

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NIST Study Confirmed ThatA Continuous Environmental Separation –Interior To Exterior Provided a 5 To 8 Year

Payback In Energy Savings!Payback In Energy Savings!

Air Barriers Started Out As …. “THE WILD, WILD WEST!”

WITH MUCH CONFUSION, THERE WAS A STAMPEDE BY MANUFACTURERS TO GET

PRODUCTS TO MARKET!

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A Multitude Of Air Barrier Products

Air Barrier Evolution

• Canada – NABA-1995 ABAA Ai B i f A i• ABAA Air Barrier of AmericaAssociation Nov/2000.

• MA Energy Code July 2001• WI 2002• MI• RI• GA• MNMN• FL

Under consideration: NY, NC, SC, IL.

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• Standards

• Testing Protocols

Air Barrier Guide Specifications Developed• Air Barrier Guide Specifications Developed


• Membership• Technical Committee• Education and Outreach Committee• House wrap CommitteeHouse wrap Committee• NEW – Transition Materials Committee• Industry initiatives

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300

Membership Growth2009: 2492010: 257ABAA

100

150

200

250

300

Membership Numbers

0

50

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

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130 Approved Contractors In 2009155 Approved Contractors In 2010

Growth Of ABAA Approved Contractors

100

120

140

160

Approved Contractors

0

20

40

60

80

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Approved Contractors

Statistics On QAP Participation - Training

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Statistics On ABAA Specified Projects

ABAA Specified Projects 2009:3942010:301

200

250

300

350

400

ABAA Specified Projects

0

50

100

150

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

ABAA Specified Projects

THE WILD, WILD WEST IS BEING SETTLED!

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Regional Differences In Construction May Cause Confusion

• Some Current, Regional Practices Are Not “Best Practice”.

• Best Practice Calls For The Containment And Conditioning Of The Inside Air.

Only Insulating Between Studs

Is Not A Best Practice.

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• Insight The Perfect Wall By Joseph W. Lstiburek, Ph.D., P.Eng., Fellow ASHRAE

Best Practice – The Perfect Wall

Cladding

Control LayersInsulation

Bulk water

Structure

Air & Vapor

Insulation

Climate Zones

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ASHRAE - Vapor Drive Zones

N o r th e rn C o ld C lim a te - V a p o r D r iv e In te r io r to E x te r io r

M o d e r a te C lim a te - V a p o r D r iv e E q u a l B o th D ire c tio n s

H o t/H u m id C lim a te - V a p o r D r iv e E x te r io r to In te r io r

ASHRAE

Class I Vapor Barrier 0.1 perm or less

Class II Vapor Barrier 1.0 perm or less and greater than 0.1 perm

American Society of Heating, Refrigerating, and Air-Conditioning Engineers

Class III Vapor Barrier 10 perm or less and greater than 1.0 perm

ASTM E 96 Test Method A (Desiccant method or dry cup method)

Vapor impermeable 0.1 perm or less

Vapor semi-impermeable 1.0 perm or less and greater than 0.1 perm

Vapor semi-permeable 10 perm or less and greater than 1.0 permp p p g p

Vapor permeable Greater than 10 perm

Proposed classifications by Joseph Lstiburek, Ph.D., P.Eng. - Building Science Corporation

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• Vapor Permeable (Air Barrier)

Air Barriers Can Be: CONFUSING!

• Vapor Permeable (Air Barrier)

• Non-Vapor Permeable (Air & Vapor

Barrier)

• Insulation (providing air, vapor and thermal protection)

Spray Applied Polyurethane Foam

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Fluid Applied Air Barrier Membranes

Sheet Applied – Peel N Stick

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Which Is More Effective In Controlling Moisture?

Controlling moisture transport via air flow?g p

Or

Controlling vapor diffusion?

HINT!

WHY ?WHY ?

Moisture Movement Above Ground

The movement of moisture into a building

Diffusion vs. Air LeakageSource: Building Science Corporation “Builders Guide”

The movement of moisture into a building through the wall assembly above grade can take two main forms. The first is the slow transmission of water vapor through vapor diffusion, driven by pressure and temperature differentials. The second is the more sever movement of moisture-laden air through porous building materials, holes and/or penetrations in the building envelope.

Addressing moisture movement above grade byAddressing moisture movement above grade by air is the most significant vehicle in eliminating moisture in the wall. Moisture movement by air accounts for 70-90% of the moisture, while the remaining 10-30% is moved by vapor diffusion.

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Air Barrier Continuity Should Be Across The Entire Envelope

Air Barriers Must Be Continuous

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What Has The Industry Done To Insure Continuity?

The evolution of industry test standards……


Testing of Air Barrier Materials

MATERIAL must have an air permeance of less 0.004 CFM/ft2 @ 1.56 lb/ft2

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ASTM E- 2178 Air Permeance Very Relevant To CMU

CMU Leaks Air Like A Sieve!


Next Logical Step Forward

Test Assemblies vs. Component Materials

ASTM E2357-05

Standard Test Method for Determining Air Leakage of Air Barrier Assemblies

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ASTM E 2357Ai L k f Ai B iAir Leakage of Air Barrier

ASSEMBLIES

ASTM E 331 Water Leakage


ASTM E 2357Ai L k f Ai B iAir Leakage of Air Barrier

ASSEMBLIES

ASTM E 331 Water Leakage

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• D1970 (8.9) Self Sealability (Head of water test)


S f B i


• Surface Burning Characteristics of Building Materials

• NFPA Codes – Healthcare Construction

• Asphaltic-based materials willAsphaltic based materials will struggle

Photo courtesy of Omega Point Laboratories

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• ASTM E84 – Provides Surface Flame Spread & Smoke Density


Smoke Density

Photo courtesy of Omega Point Laboratories

NFPA 285 - Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing


gCombustible Components

Photo courtesy of Dow Chemical White Paper – November 2009

Schematic – NFPA - 2006

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• Architects and specifiers recognize the importance of an effective air barrier for a building’s energy efficiency, g gy yhealth and durability.

• ABAA requires this testing as part of the product approval process.

ASTM E2357 is a useful tool in testing and evaluating• ASTM E2357 is a useful tool in testing and evaluating the performance of proposed air barrier assemblies under real-world conditions.

• ALMOST REAL-WORLD!


• We have put the Air• We have put the Air Barrier Opaque wall surface under a microscope.

• Extremely low i tpermeance requirements

have been established

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The Opaque Wall Is Easy To Address

AIR BARRIERS – WHAT IS THE….

What they don’t want you to know!

What they don’t’ want you to know!



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The Dirty Little Secret Is -

• Most air leakage failures aren’t going to occur through the opaque wall.

• Gypsum Board doesn’t leak a lot of air to begin with.

• CMU when treated, isn’t going to leak an appreciable amount of air.

YOU CAN STILL HAVE A MAJOR AIR BARRIER FAILURE!

WHY?

OPAQUE WALL

It is not about the WALL!

IT is about how DISSIMILAR OPAQUE WALL

TO

WINDOW / CURTAINWALL

CONNECTIONS

COMPONENTS come together!

THE WEAKEST LINK!

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Focus On The Opaque Wall Is Not Enough

What about:• Deflection joints?• Deflection joints? • Window/curtain-wall connections?• Seismic requirements?• Wall have three dimensional returns?• Continuity of the roof/wall intersect? • What products/components/assemblies make these

critical connections?critical connections? • Can connections be made in the right sequence?• Proper details? • Tested Assemblies?

Durability Of Connection Points Of Are All Impacted By:

• Wind Drift• Deflection• Deflection• Creep• Thermal Movement• Moisture Expansion• Tolerances

How Long Will The Connections Last?

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Wind Drift Is Not One Directional In Nature

Courtesy of Karol Kazmierczak,

The Construction Specifier, Oct., 2008

Wind Drift Can Be As Much As 4” On A 10 Story Building

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Envelope Performance

• Are the seals at connection points durable?

• Will they stand repeated pressurized cycling?

• Will they withstand major wind events without damage?

H ll ill h i h d h i li l d• How well will they withstand changes in live load,

wind drift, creep, settlement and thermal stress?

Test Mock-up ASTM E2357

Plywood Does Not Equal Real World

Where should the focus be to deliver an effective REAL-WORLD Air Barrier?

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The Typical Options For Attachment Of Air Barrier To Other Cladding Components?

• Sealants (Typically the primary connection method)Sealants (Typically the primary connection method)

• Self-Adhered Membranes (S-A-M)

• Spray-Polyurethane Foams

• Cured and Uncured Rubber Products

• Silicone Sheet Products

• Others?

TYPICAL SEALANT CONNECTION TO AN AIR BARRIER MATERIAL

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Sealant Limitations For Envelope Connections

• Limited by a maximum and minimum operable joint size• Limited by a maximum and minimum operable joint size.

• Limited by the amount of movement at the connection points.

• Limited by possible lack of compatibility with rubberized asphalt membrane or other sealants.

Limited by another dirty little secret!

THE DIRTY LITTLE SECRET?

Many sealants do not adhere to the polyethylene backing layer of many self-adhered

THE DIRTY LITTLE SECRET?

membranes!

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Sealant Limitations For Envelope Connections:

• Understanding performance on the polyethylene fil f SAM i iti lfilm of SAM is critical:

• Polyethylene is a natural bond breaker for sealants.

• Compatibility has two different meanings!S l t d P l th l t i ll tibl– Sealants and Polyethylene are typically compatible.

(They do not have an adverse effect on one another.)

– But many sealants do not adhere to polyethylene.

– There is variability in the composition of polyethylene.

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Best Adhesion


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• The industry has left a• The industry has left a void as to how critical connections are made:

– Termination mastic and LM products are not sealants.

AB M f t h– AB Manufacturers have typically pushed off issue to sealant manufacturers.

– “By others” further clouds the issue.

Poor

Adhesion

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• ABAA suggests - Single Source is BEST.


gg g

• Why is this important?

If you leave it to chance - then it is likely you will not get the best combination of products!


OKAY!

But remember, sticking to polyethylene is only thefirst hurdle:

• Other issues also impact sealant performance• Other issues also impact sealant performance.

• Other issues limit their use.

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• Are you relying on the perfect ¼” to ½” inch bead

of sealant to make the all the critical connections?

• Air barrier connections are not the perfect shape!

The perfect hour glass shape.

Sealants May Not Effective For Spanning Larger Gaps

A two inch wide exterior sealant joint viewed from the interior.

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Exterior “Cosmetic Seal”


Primary sealant line must traverse across mill finish closure plate and shop applied silicone sealant.

Primary (inside) seal was installed from the exterior. Intimate contact could not be made with the substrates or backer rod.


Viewed from interior side after removal of backer rod.

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Sealant Limitations For Envelope Connections -High Stress Joints

Air Temperature Surface Temperature

Rapid thermal expansion can make sealant installation an impossibility.

Sealant Limitations For Envelope Connections -High Stress Joints

Corners – A very high stress area with multi-directional movement.

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Self-adhering Membranes (SAM)

• Spin offs of below grade waterproofing technology. p g gy

• Designed to be full-adhered to:

– Structural

– Smooth surfaces

– Accommodate 1/16”

fof crack movement

– Bridge ¼” gap ONLY

Limitations Of Self-adhering Air Barrier Membranes

• All membrane manufacturers have

stated that SAM

should not bridge over gaps, voids

¼ to ½” in width

1” to 1 1/4”

¼ to ½ in width unsupported

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SELF ADHERED MEMBRANES ARE NOTINTENDED TO SPAN UNSUPPORTED GAPS

Manufacturers Typically Require A 3” LapA Misuse Of The Products

Dissimilar movement rates caused fish mouths.

Lack of seal at attachment point with minimal surface area.

caused fish mouths.

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Self-adhering AB Membranes Must Be Held Back From The Exterior Plane Of Facade

Hmmm...

Who’s sealant is this?

Who’s membrane is this?

Who’s responsible

when it leaks?

Pathways for air & water leaks.

Self Adhered Membranes Are Not Intended For Origami Tie-Ins

As value engineered

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Silicone Sealant Precludes The Use Of ASelf Adhered Membrane As A Connection

Compatible?

Asphaltic Mastic

Structural Silicone

4 Sided Structural Glazing

Air Barrier Membranes As An Unsupported Connection

M Sh d W t B t Th Will L k Ai• May Shed Water, But They Will Leak Air.

• Should Only Be Used For Their Intended Purpose.

• Do Not Have The Lateral Movement Capability Required For A Durable Seal.For A Durable Seal.

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Polyurethane Spray Foam Air Barrier

Polyurethane Foam Limitations For Envelope Connections

Drying Shrinkage

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Cracks in foam due to movement of pre-cast panels.


Spray Foam does not prevent water infiltration.

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Typically Foam yp ySystems will utilize SAM by other manufacturers.

Polyurethane Foam Limitations

If foam is to be primary AB Seal ask:

• What Testing Has Been Done (ASTM 2357)?

• Chemical and Adhesive Properties?

• Long-term drying shrinkage?

• Dynamic Movement Capability

• Weather Limitations For Installation?Weather Limitations For Installation?

• Compatibility With Other AB Seals?

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The Evolution Of Engineered Transition Assemblies

How Do You Handle Special Transitions?

2” +

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Note That Curtain-wall Race Was Milled Off To Maintain Continuity

Custom Extruded Silicone Sheet Adhered With Low Modulus Silicone Sealant

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This Condition Lead To The Development Of Pre-molded Silicone Corners

Evolution/Developments In Tested Silicone Sheet Transition Assemblies:

• Ribbed design improved sealant adhesion layerlayer.

• Thinner silicone sheet for greater visual over-site and workability.

• Adapter bar for attachment to various custom assemblies.

• Three basic design options.

• Pre-Molded corners to eliminate seamed overlaps that are prone to pull apart.

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Silicone Engineered Transition Assemblies

Evolution Of Translucent, Low Modulus,Silicone Sheet - Engineered Transition Assembly

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Engineered Transition Mock-up Assembly Mounted In Test Chamber

Test Procedure:

Engineered Transition Assembly

1. Install specimen into chamber

2. Air leakage test – ASTM E 283

3. Static water penetration test – ASTM E 331

4. Dynamic water penetration test – ASTM 501.1 @ 115 mph for 15 min.

5. Structural testing – ASTM E 330 @ 100 psf

6. Rack system 2” (three cycles) – AAMA 501.4 (Modified)

7. Repeat air infiltration – ASTM E 283

8. Repeat static water penetration test – ASTM E 331

9. Repeat dynamic water penetration test – ASTM 501.1 @ 115 mph

10. Repeat structural testing to destruction – ASTM E 330

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Racking Wall System 2 Inches – 3 Cycles

Assembly Racked 2 Inches – 3 CyclesAAMA 501.4 (Modified)

No Failures!

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ASTM E 330 -175 PSF Load. Repeated After Racking, Air, Static & Dynamic Water

Children’s Hospital Of Wisconsin West Bed Tower - Wauwatosa, Wisconsin

Shepley Bulfinch Richardson and AbbottShepley Bulfinch Richardson and AbbottOscar J. Boldt ConstructionOscar J. Boldt Construction

Trainor Glass / Fulton WindowTrainor Glass / Fulton Window

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Children’s Hospital Of Wisconsin

Self-Adhered Membrane to be covered with Metal panels


Head Condition Jamb Condition

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Children’s Hospital of WisconsinMOCK-UP AT ATI LABS, YORK, PA.

Engineered Transition Assembly Curtain-wall To Adjoining Air Barrier Assembly.

Children’s Hospital Of WisconsinHead Connection

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Continuous spans of 100’ without seams in ETA membrane.


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University Of ChicagoResidence Hall, Dining Facility

University Of ChicagoResidence Hall, Dining Facility

Deflection Joint Installation

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University Of Chicago, Residence Hall, Dining Facility Treatment Of Deflection Joint

THE WRONG WAY!THE WRONG WAY!

THE WRONG WAY!

Deflection joint mock-up

THE CORRECT WAY

Engineered Assembly –Wall To Floor Isolation Seal

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Sherman Hospital Replacement Campus

Elgin, IL

Fulton Windows

Shepley Bulfinch Richardson and AbbottWalsh Construction

Contract Glaziers Inc.

Sherman Hospital Replacement Campus Roller Application Of Air Barrier Material

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Sherman Hospital Replacement Campus Six Story Curtain-walls

Attached To Adjoining Air Barrier With An Engineered Transition Assembly

Silicone Transition Strip Pre-mounted To Curtain-wall Opening

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Wisconsin Institute For Discovery And InnovationAir Barrier With Rain-Screen Design

Ballenger Arch & Uhlein Wilson Arch, WJE Wall Consultant Findorff-Mortenson CM Joint Venture

Wisconsin Institute For Discovery And Innovation

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Wisconsin Institute For DiscoveryAnd Innovation


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ASTM E1183 – Smoke test verifies continuity of Air Barrier & Window Assembly.


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Remember The End Game:

“The Intent Is to Build Durable, Sustainable Building Enclosures.”

• Communication

Summary - A Durable Enclosure Requires

• Design Review

• Mockups

• Training

• Third Party Testing

• Complete Specifications

• A Team Approach

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Integrated Building Solutions

Connectivity:

• It’s not about the OPAQUE WALL• It s not about the OPAQUE WALL.

• It is about how wall, window, panels, components below grade, & roof come together!

• It is about addressing issues like sequence of installation and compatibility.

• It is about recognizing the need for durable, connective seals, not just seals that pass the mock-up!

Air Barrier to Window/Curtain Wall Connections

• Many Choices

• Understand Issues

• Compatible products

• Proper connectivity

• Cover yourself with good specifications

• Work with manufacturers who understand theWork with manufacturers who understand the

issues

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• Fred Kramer Building Envelope Solutions• Fred Kramer, Building Envelope Solutions Team, [email protected]

• Marcy Tyler, Technical Applications Group Manager, [email protected] oup a age , y e @ e co c co

Documents

Today’s Trends in Air Barriers - · PDF fileToday’s Trends in Air Barriers ... driven by pressure and temperature ... air is the most significant vehicle in eliminating