AIR-SHIELD LMP – Vapor Permeable Air Barrier

Product Data, W. R. MEADOWS

07 27 26
No. 724-B
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AIR-SHIELD LMP is a water-based air/liquid moisture barrier that cures to form a tough, seamless, elastomeric membrane. AIR-SHIELD LMP exhibits excellent resistance to air leakage. When properly applied as a drainage plane, AIR-SHIELD LMP prohibits liquid water intrusion into the substrate.

AIR-SHIELD LMP has been specifically formulated to act as an air and liquid moisture barrier, allowing vapor to pass through it.   It may be applied to most common surfaces and integrated into various wall systems. AIR-SHIELD LMP is suitable for both new construction and retrofit applications.


  • High permeability – allows the transmission of moisture vapor through porous building materials.
  • Highly flexible – bridges cracks, which may form in the substrate.
  • UV resistant – gray membrane can be left exposed up to six months. Black membrane can be exposed for an indefinite period and is ideal for exposed applications, such as beneath rain screen panels.
  • User friendly – single-component, water-based technology allows for simple, safe application and easy cleanup.
  • Liquid applied – simplifies detailing and assures a monolithic, seamless membrane when applied to a rough or smooth surface.
  • Sprayable – with appropriately configured airless spray equipment – low application costs.
  • Excellent adhesion – remains firmly bonded to the substrate, even when applied over damp surfaces.
  • Self-sealing – Nails and fasteners can be used without compromising performance.
  • Low VOC content.

5 Gallon (18.93 Liter) Pails
55 Gallon (208.20 Liter) Drums

Application Rate:                25 ft.2/gal. (0.6 m2/L)
Wet Film Thickness:           60 mil (1.5 mm)
Cured Film Thickness:        30 mil (0.8 mm)

When stored indoors in original, unopened containers at temperatures between 40° – 90° F (4° – 32° C), shelf life is one year from date of manufacture.


  • Exceeds Air Barrier Association of America (ABAA) requirements for fluid-applied air barriers.
  • Exceeds ABAA maximum assembly air leakage requirements when tested in accordance with ASTM E 2357.
  • Exceeds ABAA maximum material air leakage requirements when tested in accordance with ASTM E 2178.
  • Exceeds the requirements of the Massachusetts Commercial Energy Code for Building Envelope Systems.
  • 2010 National Building Code of Canada
  • Complies with all current federal, state, and local maximum allowable VOC requirements, including U.S. EPA, LADCO, SCAQMD, and OTC.
  • Complies with Canada VOC Concentration Limits for Architectural Coatings Regulations.
Solids Content, %: 58
Color: Gray
(Black – special order only)
Flexibility @ -26° C (-15° F), PASS
(ASTM C 836):
Elongation (ASTM D 412), %: 1200
Water Vapor Permeance 12
(ASTM E 96, Procedure B) Perms:
Service Temperature: Not to exceed 175° F
(80° C)
Nail Sealability (ASTM D 1970): Pass
Storage Temperature 40 – 90° F  (4 – 32° C)
Air/Substrate Temperature
(At Time of Application):
 >20° F (-6.7° C)
VOC Content 90 g/L


Test Method ASTM E 2178 ASTM E 2357
Pressure 75 Pa
(1.57 lb./ft.2)
75 Pa
(1.57 lb./ft.2)
ABAA Requirements 0.004 cfm/ft.(0.02 L/S/M2) 0.04 cfm/ft.2
(0.2 L/S/M2)
AIR-SHIELD LMP Results <0.004 cfm/ft.(0.02 L/S/M2) <0.04 cfm/ft.2
(0.2 L/S/M2)

AIR-SHIELD LMP conforms with ASTM E 84, Class A.

AIR-SHIELD LMP may be used in NFPA 285 complying wall assemblies.  Contact W. R. MEADOWS for further information.

Surface Preparation … All surfaces must be clean (free of all coatings and curing compounds), free of frost, structurally sound, and relatively smooth. AIR-SHIELD LMP can be applied to “green” or damp concrete if there is no liquid water on the surface. Prepare substrate per manufacturer’s instruction prior to membrane application.

Exterior Sheathing Panels … Exterior sheathing panels are to be installed and fastened per manufacturer’s recommendation. For detailed application information, see INSTALLATION INSTRUCTIONS: JOINT TREATMENT OF EXTERIOR SHEATHING PANELS WHEN USING AIR-SHIELD FLUID APPLIED MEMBRANES.


Concrete Masonry Units … Before applying AIR-SHIELD LMP to CMU surfaces, patch all cracks, protrusions, small voids, offsets, details, irregularities, and small deformities with MEADOW-PATCH® 5 or MEADOW-PATCH 20 from W. R. MEADOWS at least two hours before application.

Appearance … AIR-SHIELD LMP (gray) will dry gray in color.  AIR-SHIELD LMP (black) appears dark gray in the container, but the dried film will be black.

Temperature/Conditions … Apply AIR-SHIELD LMP at air and surface temperatures of 20˚ F (-6.7° C) and higher.  Curing/drying times are dependent on air temperature, airflow, relative humidity, substrate temperature, etc., specific to each individual application.  Typical results are:

Tack-Free Time:  2 hours
Full Cure:              48 hours

Roller … AIR-SHIELD LMP can be applied directly from the container; a ¾” (19.1 mm) nap roller is recommended.  Apply AIR-SHIELD LMP on a vertical surface, in multiple coats if necessary, to achieve a final film thickness of 60 mils wet (30 mils dry).  NOTE:  While the proper film thickness may be achieved with a single coat, multiple coats may be necessary if the material slumps due to temperature and/or substrate conditions.  Allow each previous coat to dry (approximately one hour) prior to applying the next coat.

Sprayer … AIR-SHIELD LMP should be stored and maintained at a temperature of 60˚ F (15.6° C) or higher throughout the entire spray application.   The product will become thick and difficult to spray at temperatures below 60˚ F (15.6° C).  Note:  Use of Graco HydraMax 350 or Graco GH833 is recommended for optimum performance.  A Graco heavy duty texture gun with either a 0.051″ (Graco GHD 551), 0.035″ (Graco GHD 535), or 0.037″ (Graco GHD 537) spray tip is recommended.  If cratering occurs, the GHD 535 or 537 is recommended for a smoother finish.

Spray AIR-SHIELD LMP on a vertical surface, in multiple coats if necessary, to achieve a final film thickness of 60 mils wet (30 mils dry).   NOTE:  While the proper film thickness may be achieved with a single coat, multiple coats may be necessary if the material slumps due to temperature and/or substrate conditions.  Allow each previous coat to dry (approximately one hour) prior to applying the next coat.

Film Thickness … Frequently inspect the surface with a wet film gauge to verify that proper film thickness is achieved, and that the film thickness is uniform over the entire surface.  Porous substrates, masonry blocks, etc., may require multiple coats to achieve recommended film thickness.

Cleanup … Material should not be left in the pump, lines, or gun when finished spraying.  After spraying, flush water through the system until pump and hose are clear (approximately five gallons).  Aromatic solvents, such as xylene or toluene (approximately two gallons) can be used for final flushing after water is flushed through the pump and lines.  Water should be flushed through the machine to remove any solvent prior to spraying of AIR-SHIELD LMP.

DO NOT FREEZE. Keep containers tightly sealed. Maximum UV exposure period for grey membrane is six months; unlimited for black.  Do not apply AIR-SHIELD LMP if rainfall or snow is forecast or imminent within 12 hours of application.

Direct contact may result in mild irritation to the skin and eyes.  Should adverse effects occur, remove subject from area immediately.  If irritation occurs and persists, move victim from exposure source and treat symptomatically.  Flush affected areas with mild soap and water.  Refer to safety data sheet for complete health and safety information.

Please contact W. R. MEADOWS for specific details and/or data not outlined in this literature. Technical assistance, from design to product application, is available upon request.

May help contribute to LEED credits:

  • EA Credit 1: Optimize Energy Performance
  • IEQ Credit 3.1: Construction Indoor Air Quality Management Plan: During Construction
  • IEQ Credit 4.2: Low-Emitting Materials: Paints & Coatings
  • IEQ Credit 7.1: Thermal Comfort – Design
  • MR Credit 2: Construction Waste Management
  • MR Credit 5: Regional Materials


This material last updated April 2014.


W. R. MEADOWS, INC. designs, manufactures, and markets high-quality building materials for today's construction professionals. Products are sold through an authorized distribution network. The family-owned and operated company focuses on product quality, exceptional service, and trusted integrity since its founding in 1926.
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