To finish strong over hairline cracking common in stucco and masonry you need a Superior Architectural Coating.  Formulated with 100% pure acrylic elastomeric polymers, Elasto-flex dries to a stretchy rubber-like film on the surface yet is vapor permeable.


  • Bridges minor hairline cracks typical in stucco and masonry
  • Flat finish
  • 100% Acrylic Polymers for durability
  • Highly Flexible
  • Water-based – easy clean up with water

Coverage per pail (sf/sm)*
One Coat: 375-400 sf/pail (34-37 sm)
Two Coat: 187-200 sf/pail (17-18.5 sm)
*All coverage is approximate and depend upon substrate, details and individual application

Packaging/Shelf Life/Storage
5 gallon (19L) pail Pail
Weight: 53 lbs (24 kg)
Shelf Life: 2 years
Storage: Protect from extreme heat (90°F (32°C), freezing and direct sunlight.

Application Temperature: 40°-110°F (5°-43°C)
Dry to Touch: 2-4 hours at room temperature
Recoat Time: 8 hours at room temperature
Dry Time: 12 hours at room temperature
Working and drying time will vary with temperature and humidity.

Technical Data (Neat Film)
Water Vapor Transmission: >10 perms
Elongation: 307%
Tensile Bond @ Break: 84 psi
Mildew Resistance, ASTM D3273: Pass

Freeze/Thaw ASTM E2485 (Method B): No deleterious effects after 10 cycles – Pass

Solids by Weight: 59.5

Solids by Volume: 45.4

Air and substrate temperature for application of Elasto-flex must be 40°F (5°C) or higher and must remain 40°F (5°C) or higher for a minimum of 24 hours. Provide temporary protection to protect the wall system from damage until permanent flashings, caps and sealants are installed. Store materials within prescribed temperature limits and out of direct sunlight. High temperatures will reduce working times, Low temperatures and/or high humidity and pigment loading will extend working, set and dry times.

Surface temperature must be above 40°F (5°C). Surface must be clean, dry, structurally sound and free of  efflorescence, oil, grease, form release agents, and curing compounds. On previously painted surfaces, all loose,
peeling and chalking paint must be removed. Any glossy areas must be sanded.

Concrete – Must have cured a minimum of 28 days prior to the application of Elasto-flex. If form release agents or curing compounds exist on the surface, they must be removed with an appropriate solution. Remove any residual solution by flushing with water.

Masonry – Clean, cured, dry.

Stucco – Must be cured, dry. If additives were used in the stucco, it is recommended that a test patch be made to evaluate bond strength of the Elasto-flex to the stucco.

Master Wall® Superior Finishes—Clean and dry.

Priming—Prime new surfaces such as concrete, masonry and stucco with Master Wall Primecoat to equalize substrate absorption. Priming is not necessary over Master Wall Superior Finishes.
Mixing – Thoroughly stir Elasto-flex into a homogenous consistency. Small amounts of clean, potable water may be added to obtain a workable consistency. Do not over mix. Do not exceed 12 ounces (0.35L) of water per pail. Do not add accelerators or retarders to Elasto-flex.
Application – Elasto-flex can be applied by brush, roller, or airless spray equipment. When using a roller, a maximum ¾” nap is recommended. Apply Elasto-flex in an even, continuous coat, maintaining a wet edge of 20
mils wet for a dry thickness of 10 mils in one to two-coats with no pinholes.

Tools and equipment can be cleaned with soapy water when Elasto-flex is wet.

Do not use Elasto-flex as a finish directly over any Master Wall base coat.

    Apply finish coats away from direct sunlight. Cold joints or color variations can occur if the finish dries too quickly.
  • Under certain conditions dark colors may show efflorescence on the surface during the cure process.
    Surfaces exposed to the weather must be sloped (6:12 minimum).
  • Deep, intense colors should be specified with DuroTone pigments to maintain colorfastness longer. Verify specialty colors with your Master Wall® Distributor.

Hazard: This chemical is not considered hazardous according to the OSHA Hazard Communication Standard 2012 (29 CFR 1910.1200).
VOC: Less than 50 g/L.

Approved Substrates
Master Wall® Textured Finishes
Others approved in writing

Spray – Changes in pressures and tip sizes may be needed for proper spray characteristics.
Reducer: No reduction necessary, see mixing instructions if water is added.
Airless Spray: Pressure 2000-2700 p.s.i.
Tip .021 inch
Brush – Use a nylon/polyester brush.
Roller Cover – Use a 1/2 to 1-1/2 inch nap synthetic cover.

The substrate and its condition will determine the application procedure.

Considerations to minimize pinholes:
• 2-coat application with overnight drying between coats.
• Spray application with backrolling.
• Power rolling.
• Do not paint in direct sun or on a hot surface.
• Do not reduce.

This product is subject to a written limited material or system warranty. Obtain a warranty from the Tech Support tab of our website. Refer to Specifications for more complete information on proper use and handling of this product.

Information contained in this product data sheet conforms to the standard detail recommendations and specifications for the installation of Master Wall® Inc. products and is presented in good faith. Master Wall Inc. assumes no liability, expressed or implied as to the architecture, engineering, or workmanship of any project. This information may be concurrent with, or superseded by other applicable documents, such as specifications and details. Contact Master Wall® Inc. for the most current product information.