Unit A, 21/F, KP Tower, 93 King’s Road, North Point, Hong Kong(852) 2911 0103

W.R. MEADOWS AIR-SHIELD Flashing Membrane


AIR-SHIELD Self-Adhering Air/Vapor and Liquid Moisture Barrier

AIR-SHIELD self-adhering air/vapor and liquid moisture barrier is part of a total W. R. MEADOWS system to complete the building envelope. It is a roll-type product that is nominally 40 mils thick. The membrane’s controlled thickness is fabricated from cross-laminated polyethylene bonded to specially modified asphalt.


This unique, self-adhesive membrane, protected by a special release paper, is strong and durable. It remains flexible when surface mounted and will adhere to most primed surfaces at minimum temperatures of 40° F (4° C).   The membrane provides excellent protection as a tough barrier that won’t shrink, sag, dry out, crack, or rot. It offers excellent resistance to punctures during installation. AIR-SHIELD can also be used as a transition membrane to provide protection against water infiltration in critical detail areas, such as window and door openings, deck-to-wall intersections, corner boards, wall-to-wall tie-ins, foundation sill plates, sheathing panel seams, under stucco finishes, masonry walls, and other non-roof detail areas.


AIR-SHIELD is packaged in rolls of 38.5″ (.97 m) x 75′ (22.86 m).  AIR-SHIELD can also be cut to desired width.


Optional sizes include:
4″ x 75′, 6″ x 75′, 9″ x 75′, 12″ x 75′, 16″ x 75′
18″ x 75′, 20″ x 75′ and 24″ x 75′.


AIR-SHIELD should be stored palletized and protected from rain and/or physical damage. Do not store at temperatures above 90º F (32.2º C) for extended periods of time. Do not leave membrane exposed to direct sunlight. Do not double-deck pallets.  Store away from sparks or flames. Outdoors, store AIR-SHIELD on pallets and completely cover.


AIR-SHIELD self-adhering air/vapor and liquid moisture barrier is designed for a variety of uses.


Primary applications include cavity wall and masonry wall construction. AIR-SHIELD works equally well as an air and/or vapor barrier on precast concrete, cast-in-place concrete, masonry (concrete block), interior and exterior gypsum board, Styrofoam, primed steel, aluminum mill finish, anodized aluminum, primed galvanized metal, drywall, and plywood.



  • Exceeds the requirements of the Massachusetts Commercial Energy Code for Building Envelope Systems.
  • Meets CAN/CGSB-51-33, Type I Water Vapor
    Permeance Requirements.
  • ABAA Section 07261 Self-Adhering Air and Vapor Barrier Specification


AIR-SHIELD provides an effective barrier to air exfiltration and infiltration, reducing condensation within the wall assembly, and increasing efficiency of a building’s mechanical system.  Wet insulating materials lose much of their R-factor performance characteristics, reducing the energy efficiency of the structure. W. R. MEADOWS thermal and moisture protection products play a key role in maintaining the structure’s energy efficiency and aiding in the integrity of other structural systems, such as insulation.



Thickness:40 mils (1 mm)
Pliability @ -25° F (-32° C)No effect
Tensile Strength Film
ASTM D412 modified (MD):
ASTM D882 (MD): lb/in.
4000 psi (27.6 MPa)
23.5 lb/in. (4.1 N/mm)
Elongation Film:
ASTM  D412 modified (MD, %):
ASTM D882, (MD, %):
400 (Typical)
400 Min.
Puncture Resistance:
40 lbf (178 N) Min.
Water Vapor Permeance
(free film)

ASTM E96, Procedure B
0.035 Perms
Water Absorption
(% by weight):
ASTM D1970
ASTM D570-81
0.25 Max
0.1 Max.
Application Temperature:40° F (4° C) Min.
Low Temperature
@ -22° F (-30° C)
(CGSB 37-gp-56m)
Service Temperature-40° F to 158° F
Lap Peel Strength @ 39° F (4° C)
(ASTM D903, 180 Bend)
10 lbf/in width
(1.75 N/mm)

**Air leakage tested per ASTM E 283



  • Low permeability – prevents the transmission of air and inhibits moisture vapor through porous building materials.
  • Provides a complete above-grade air, vapor, and water barrier on a variety of construction materials.
  • Controlled thickness membrane is ideal for air barrier applications.
  • Cross-laminated polyethylene film has excellent tensile strength, elongation, and tear resistance.
  • Modified membrane is flexible at low temperatures.
  • Excellent adhesion to prepared substrates of precast concrete, cast-in-place concrete, masonry (concrete block), interior and exterior gypsum board, Styrofoam, primed steel, aluminum mill finish, anodized aluminum, primed galvanized metal, drywall, and plywood.
  • Self-sealing around fasteners
  • No flame required.
  • Low temperature version also available – can be applied at temperatures between 20˚ F (-7˚ C) and 60° F (16° C).
  • AIR-SHIELD XLT can be applied at minimum temperatures of 0° F (-18° C).


Air leakage tested per ASTM E283, ASTM E2178-01, and ASTM E2357

PressureAir Leakage
(National Building Code of Canada Requirement)
Results for
Air Leakage
(National Building Code of Canada Requirement)
Results for
Palb./ft.2L/S/M2 cfm/ft.2 
751.570.02< 0.020.004

< 0.004



Surface Preparation

All surfaces to be protected must be clean, dry, frost-free, and smooth. Remove any sharp protrusions and repair all defects.


All surfaces to receive AIR-SHIELD must be clean of oil, dust, and excess mortar.  Strike masonry joints flush.  Concrete and masonry joints should be cured at least 72 hours, be clean, dry, smooth, and free of voids. Repair spalled areas; fill all voids and remove all sharp protrusions. Concrete must be cured a minimum of 14 days and must be dry before AIR-SHIELD is applied.  Where curing compounds are used, they must be clear resin-based, without oil, wax or pigments.  Prepare substrate per manufacturer’s instruction prior to application of membrane.


All surfaces to which AIR-SHIELD is to be applied must be addressed with MEL-PRIME or MEL-PRIME W/B adhesive from W. R. MEADOWS. MEL-PRIME may be applied to an area that is to be covered the same day. Uncovered areas must be re-addressed the next day. See container for complete application directions, drying information, and precautions.


Application Method

AIR-SHIELD self-adhesive air/vapor and liquid moisture barrier can be applied at minimum temperatures of 40º F (4º C). Apply membrane to surface addressed with MEL-PRIME by removing release paper and rolling membrane firmly into place. Remove release paper only as membrane is being applied.  Ensure membrane is fully adhered and remove all wrinkles and/or fish mouths. Cut AIR-SHIELD membrane with a utility knife to detail around protrusions and masonry reinforcing. Seal all end laps and protrusions with POINTING MASTIC from W. R. MEADOWS.  Overlap subsequent courses of membrane a minimum of 2.5″ (63.5 mm). Vertical terminations of AIR-SHIELD should either be tied into the wall system or mechanically fastened with TERMINATION BAR from W. R. MEADOWS.  AIR-SHIELD is not designed for permanent exposure. Good construction practices call for application of insulation as soon as possible to protect the air barrier.


When used as a flexible wall flashing, AIR-SHIELD should be recessed ½” (13 mm) from the face of the masonry.  Flashing should not be permanently exposed to sunlight.  Do not allow the rubberized asphalt surface of the flashing membrane to come in contact with sealants containing solvents, creosote, uncured coal tar products, EPDM, or PVC components.



Tools, etc. can be cleaned with mineral spirits, paint thinner or aromatic solvent.


Coverage is approximately 240 ft.2 (22.3 m2). Net coverage when lapped 2.5″ (63.5 mm) is 228 ft.2 (21.1 m2).


No adverse effects expected with normal product use. Cotton work gloves and safety glasses are recommended.