Detailing Air Barriers

1. WELCOME

2. Who are we?
• 1926 - First manufacturing plant in Elgin, IL
• Single family ownership
• Continued growth to bring regional
manufacturing to all points in North America
• 11 facilities throughout North America (3 in
Canada)

3. The Meadows’ Family of Products
Expansion Joint Materials
Concrete Restoration
Construction Liquids
Joint Sealants
Decorative Concrete
Building Envelope

4. Complete System
• Air Barriers
• Vaporproofing
• Waterproofing
• Drainage

5. CONTROLLING AIR
LEAKAGE AND
MOISTURE
MOVEMENT: AIR
BARRIER DETAILING

6. This program is registered with the 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.
W. R. MEADOWS is a Registered Provider with the American Institute of
Architects (AIA) Continuing Education Systems. Credit earned on completion of
this program will be reported to CES Records for AIA members. Certificates of
Completion for non-AIA members are available on request.

7. Objectives
• Review air barrier systems and why they are important to a building’s energy
savings
• Identify difficult air barrier details in various types of building envelope
construction
• Discuss installation and applications of liquid and membrane air barriers
around rough openings, corners, building joints, and junctions of different
materials
• Illustrate methods that save time or improve application and installation

8. High Performance Building
• “Can be defined as a building
that integrates and optimizes on
a life cycle basis all major high
performance attributes,
including energy conservation,
environment, safety, security,
durability, accessibility, cost-
benefit, productivity,
sustainability, functionality and
operational considerations”
- Energy Independence
and Security Act of 2007

9. High Performance Building
• “Can be defined as a building
that integrates and optimizes on
a life cycle basis all major high
performance attributes,
including energy conservation,
environment, safety, security,
durability, accessibility, cost-
benefit, productivity,
sustainability, functionality and
operational considerations”
- Energy Independence
and Security Act of 2007

10. Moisture Movement
• Hydrologic Cycle
• Gravity
• Capillarity
• Diffusion Through a Material
• Air Transport
• Dew Point

11. Moisture Movement
• Hydrologic Cycle
• Gravity
• Capillarity
• Diffusion Through a Material
• Air Transport
• Dew Point

12. Moisture Movement
• Hydrologic Cycle
• Gravity
• Capillarity
• Diffusion Through a Material
• Air Transport
• Dew Point

13. Moisture Movement
• Hydrologic Cycle
• Gravity
• Capillarity
• Diffusion Through a Material
• Air Transport
• Dew Point

14. Moisture Movement
• Hydrologic Cycle
• Gravity
• Capillarity
• Diffusion Through a Material
• Air Transport
• Dew Point

15. Moisture Movement
• Hydrologic Cycle
• Gravity
• Capillarity
• Diffusion Through a Material
• Air Transport
• Dew Point
EXTERIOR AIR
30˚ F
30% RH
INTERIOR
AIR
70˚ F
30% RH
THEORETICAL
DEW POINT
COLD HEAT
37˚

16. Air Leakage
• The flow of air through gaps and cracks in
the building envelope.
• Uncontrolled air leakage increases the
amount of heat loss as warm air is
displaced through the envelope by colder
air from outside.
• Air leakage of warm damp air through the
building structure can also lead to
condensation within the envelope
(interstitial condensation), which reduces
insulation performance

17. Air Flow
• Wind Pressure
• Stack Pressure
• Mechanical Pressure

18. Air Leakage and Vapor Diffusion during a
Heating Season in New York
Air Leakage and Vapor Diffusion during a
Cooling Season in Florida
Graphics used courtesy of WBDG and NIBS
Why stop the flow of air into and through
the Building Enclosure System ?

20. Why stop the flow of air into and through
the Building Enclosure System ?
• Air flow into and out of buildings can affect the location of the
dew point.
• Air leakage into and out of buildings causes the HVAC system
to expend extraneous energy in order to maintain the
building’s desired temperature and humidity levels.
• Air flow is a vehicle by which sound travels.
• Air flow is a vehicle by which particulate matter travels.
• Air flow is a vehicle by which odors and gaseous substances
travel.

21. Air Flow
• Air Barriers cannot be dealt with without understanding that they
are part of a wall assembly
• N.B Hutcheon’s CBD-48 – Requirements of Exterior Walls (1963)

22. Building Enclosure
• Cladding
• Structural component
• Control Layers
• Water control layer
• Air control layer
• Vapor control layer
• Thermal control layer

23. Air Control Layer
A system of building assemblies within the building enclosure—
designed, installed and integrated in such a manner as to stop the
uncontrolled flow of air into and out of the building enclosure.
The air barrier membrane is an integral part of this system.

24. Effective Air Barrier System Characteristics
STRONG - Be capable of withstanding positive and negative wind, fan
and stack pressures
DURABILITY - Be durable and maintainable
CONTINUOUS - all joints, laps, and seams airtight
RESILIENT - Be flexible in nature to allow for different substrate
movements, expansions and contractions

25. Air Leakage
• THEORETICALLY fairly easy
to deal with
• Stop the air flow…make sure
there are no gaps or cracks
• REALISTICALLY…Easier said
than done

26. Layers of air barrier system
Air Barrier System
Air Barrier Assembly
Air Barrier Assembly
Air Barrier Material
Air Barrier Material
Air Barrier Material
Air Barrier Material

27. Types of Air Barrier Materials
• Self-Adhered Sheet Materials

28. Types of Air Barrier Materials
• Fluid Applied Materials – Non-foaming

29. Types of Air Barrier Materials
• Mechanically Fastened – Insulating Boardstock

30. Types of Air Barrier Materials
• Mechanically Fastened Membranes – Film Materials

31. Types of Air Barrier Materials
• Fluid Applied - Foaming

32. Air Barrier Components
• Transition membrane--used where backup
is interrupted (joints) or where there will be
movement in the substrate
• Tape (mesh or peel/stick)--For fluid‐applied
products, the joints of the sheathing boards
must be filled or taped, and the mortar
joints of masonry units must be filled and
cut off flush.
• Primer/Adhesive--For proper adhesion of
self‐adhering sheet membrane air barriers.
• Mastic--to seal edges, ends.
• Termination bars—Mechanical adhesion
• Joint filler, patching compounds

33. Design of Air Barrier
• Keep it simple!
• Decide which layer provides the air
barrier.
• Minimize different types of construction
within the envelope
• Ensure continuity and pay attention to
details and sequencing
• Minimize penetrations of envelope
• Where penetrations are unavoidable,
develop details that are simple to
construct and provide continuity

34. Design – Plan Review
• Air barrier is usually depicted as a
single line on the drawings, then left to
the builder to specify what it’s
comprised of and how to achieve
continuity
• Rarely are details included that indicate
products to be used, sequencing or
compatibility
• By the time the inspector arrives,
installation has begun and corrections
result in change orders
• Dedicated plan review for air barrier

35. Design – Tricky Parts
Transitions:
• Roof‐to‐wall
• Foundation‐to‐wall
• Wall‐to‐door/window
• Wall‐to‐curtain wall
• Relieving angles, joints
• Mechanical/electrical/structural
penetrations
• Differing cladding or backup

36. Design – Specification
• Examine performance reports/testing—
does it meet code requirements?
• Proprietary or performance based instead
of generic terms to avoid confusion in the
field
• Hold the specification
• Every product has application, performance
specifics—no one size fits all.
• If different manufacturers are specified for
one system, evaluate compatibility.

37. Before You Specify
• Special tools
• Product durability: track record, history matter.
• Costs: compare apples to apples
• Full set of system components
• Manufacturers support
• Performance/ code requirements
• Project conditions.
• Compatibility with adjacent materials
• Heat Tolerance requirement
• Rainfall resistance
• Self-sealing capability

38. Pre-Installation Meeting
• Discuss connections, sequence of
making airtight/flexible connections
between assemblies
• Identify responsibility
• Ensure that the materials being joined
together are compatible
• All trades touching the air barrier
• Mock-up
• Quality Control
• Compatibility
• Special Conditions

39. Labor Considerations
• Materials selection
• Number of joints
• Substrate condition/preparation
• Location
• Environment/Climate
• Installation Sequence
• Coordination with details for other
systems
• Number of penetrations
• Rough openings

40. Substrate Conditions
• Substrate moisture
• Glass Faced Gypsum
• Surface profile
• Control joints
• Wood—beware of staples, movement
• Sheathing joint treatments

41. Material Selection
Liquid or Sheet Membrane
Which would you choose?

42. Material Incompatibility
• Some membranes react with insulation
or adhesives and cause deterioration
• Avoid pairing bituminous materials with
EPDM and PVC (careful at roofs).
• Careful of mastic applied near
urethanes, silicone sealants.

43. Adhesion

44. Connections
• Roof, wall, windows, doors,
foundations, floors over crawl
spaces, ceilings under attics and
across building joints must be
flexible.
• Must withstand building
movement due to thermal, seismic,
moisture and creep.
• Joints must support the same air
pressures as the air barrier
material without displacement

45. Roof – Wall Connections

46. Penetrations

47. Fasteners
So close…

48. Fasteners

49. Shelf Angle

50. Base of Wall

51. Joint Treatment

52. Joint Treatment

53. UV exposure

54. Damage

55. Poor Workmanship

56. Shadowing

57. Rough Openings

58. Rough Openings

59. Rough Openings

60. Rough Openings – Self-Adhesive

61. • Prime the area as recommended by the
membrane manufacturer according to the
substrate.
• Pre-cut membrane to ensure ease of handling.
• Apply first pre-cut strip at the base of the
rough opening, rolling firmly into place,
ensuring a min. 3” extending onto the wall and
into the rough opening.
• Ensure all edge overlaps are a minimum of 2”
and end to end overlaps are 4”.
• Seal terminations with mastic.

62. Rough Openings – Liquid Flashing

63. Summary
• Air barriers are an essential part of a building’s energy savings and durability
• Air barrier installation needs to be addressed during the design stage and all
factors need to be considered
• Performance of an air barrier system is dependent on the details
• Consider materials and systems that save time or improve application and
installation