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
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Premature Deterioration Of 1970- 1980’s Led To Adoption Of Air Barrier Codes
Northern Climates Were Prone To Greater Deterioration
10/26/2010
4
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
10/26/2010
5
Window, Roof, Soffit Intersects All Proved To Be Trouble Areas
Older Buildings May Not Have Leaked Water, But They Leaked Air!
10/26/2010
6
In Some Cases Severe Air Leakage lead to Complete Re-Cladding
Past Building Practices Focused More On Water Shed Versus
Continuous Air Seal
10/26/2010
7
Energy Loss And Wall Damage Were Caused By Air Leakage
Poor Quality Mortar Joints Added To The Outbound Air Flow
10/26/2010
8
Assembly Transitions Lacked Durable Air Seals
Seals Were Not Made Around Penetrations
10/26/2010
9
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.
10/26/2010
10
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!
10/26/2010
11
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.
10/26/2010
12
Air Barrier Evolution
• Standards
• Testing Protocols
Air Barrier Guide Specifications Developed• Air Barrier Guide Specifications Developed
Air Barrier Evolution
• Membership• Technical Committee• Education and Outreach Committee• House wrap CommitteeHouse wrap Committee• NEW – Transition Materials Committee• Industry initiatives
10/26/2010
13
300
Membership Growth2009: 2492010: 257ABAA
100
150
200
250
300
Membership Numbers
0
50
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
10/26/2010
14
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
10/26/2010
15
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!
10/26/2010
16
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.
10/26/2010
17
• 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
10/26/2010
18
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
10/26/2010
19
• 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
10/26/2010
20
Fluid Applied Air Barrier Membranes
Sheet Applied – Peel N Stick
10/26/2010
21
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.
10/26/2010
22
Air Barrier Continuity Should Be Across The Entire Envelope
Air Barriers Must Be Continuous
10/26/2010
23
What Has The Industry Done To Insure Continuity?
The evolution of industry test standards……
Air Barrier Evolution
Testing of Air Barrier Materials
MATERIAL must have an air permeance of less 0.004 CFM/ft2 @ 1.56 lb/ft2
10/26/2010
24
ASTM E- 2178 Air Permeance Very Relevant To CMU
CMU Leaks Air Like A Sieve!
Air Barrier Evolution
Next Logical Step Forward
Test Assemblies vs. Component Materials
ASTM E2357-05
Standard Test Method for Determining Air Leakage of Air Barrier Assemblies
10/26/2010
25
Air Barrier Evolution
ASTM E 2357Ai L k f Ai B iAir Leakage of Air Barrier
ASSEMBLIES
ASTM E 331 Water Leakage
Air Barrier Evolution
ASTM E 2357Ai L k f Ai B iAir Leakage of Air Barrier
ASSEMBLIES
ASTM E 331 Water Leakage
10/26/2010
26
• D1970 (8.9) Self Sealability (Head of water test)
Air Barrier Evolution
S f B i
Air Barrier Evolution
• Surface Burning Characteristics of Building Materials
• NFPA Codes – Healthcare Construction
• Asphaltic-based materials willAsphaltic based materials will struggle
NFPA 285 - Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing
Air Barrier Evolution
gCombustible Components
Photo courtesy of Dow Chemical White Paper – November 2009
Schematic – NFPA - 2006
10/26/2010
28
Air Barrier Evolution
• 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!
Air Barrier Evolution
• 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
10/26/2010
29
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!
What they don’t’ want you to know!
What they don’t’ want you to know!
10/26/2010
30
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!
10/26/2010
31
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: