To finish strong you need a leveling base coat with superior weather resistance to stop water before it enters your stucco or wall. Flexible, fibered SuperiorShield WeatherSTOP remains flexible, weather resistant and embeds easily into Master Wall® mesh. WeatherSTOP is an alternative to a separate fluid applied water barrier.

  • WeatherSTOP blocks water before it soaks the stucco keeping your building dry.
  • Protects the stucco, keeps it safe and dry.
  • Dry stucco doesn’t support mold growth.
  • Bridges minor hairline cracks, flexible.
  • Levels the surface, makes the surface smooth for finishing.
  • Can be used with Master Wall Mesh for even better crack resistance.
  • Works with Master Wall Superior and Superior Elastomeric Plus textured finishes.


VOC: <1% by Weight Manufacture Locations: 30058 • 77474 • 84651

Packaging: 5 gallon (19L) pail

Pail Weight: 60 lbs (27 kg)

Shelf Life: 2 years

Coverage (estimated)

  • Embedding Single-layer of Mesh: 200-220 sf (18.6-20 sm)
  • Double Layer of Mesh: 66-200 sf (6-18.6 sm)


Aggre-flex EIFS
Aggre-flex Drainage EIFS
Cemplaster Fiberstucco
ICF Coatings
QRW1 Drainage EIFS
Rollershield Drainage CIFS®
Soffit System
Stucco Cement Board Coatings
Uninsulated Finishes

Approved Substrates

Master Wall Base Coats
Prepared & Base Coated Surfaces of Brick, Concrete, Masonry
Exterior gypsum sheathing
(ASTM C1396, C1177)
Dens Glass Gold®
Gold Bond e2xp®
Util-A-Crete®, ProTEC®, ProGUARD®
Others approved in writing

Application Procedure

Job Conditions – Air and substrate temperature for application of WeatherSTOP 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. Working and drying times are based upon normal room temperature conditions and will vary with temperature and humidity.

Preparation – The substrate must be approved by Master Wall Inc.®, clean, dry, structurally sound and free of efflorescence, oil, grease, form release agents and curing compounds or anything that would affect bond. Stucco should cure a minimum of 24 hours and concrete/masonry a minimum of 28 days before application. Painted surfaces are not acceptable and must be removed. Surface should be true to within 1/4” in 10-0” (6 mm in 3 m) and clear of excessive fins and voids.

Mixing – Thoroughly stir WeatherSTOP using a heavy duty 1/2” (12.7 mm) drill at 400 – 500 rpm and a heavy duty mixing paddle. Pour half of the stirred WeatherSTOP into a clean plastic pail. Up to 12 ounces (0.35L) of clean, potable water may be added to adjust workability. Add 20lbs (9 kg) Type I or I-II Portland cement to the half pail of WeatherSTOP and mix to a homogenous consistency. Let the mixture stand for 3 to 5 minutes and then stir to a creamy consistency. Do not exceed 24 ounces (0.7L) per pail. Do not over mix as faster setting or reduced working time can occur. Do not add accelerators or retarders to the WeatherSTOP mixture.


Water Barrier Application – Apply the WeatherSTOP mixture over the entire surface of the approved substrate in a thickness of approximately 1/16” (1.6 mm).

With Optional Mesh Application – Apply the WeatherSTOP mixture over the entire surface of the approved substrate in a thickness greater than that of the reinforcing fabric being used (approximately 1/16” (1.6 mm) for Standard Mesh). Immediately embed the reinforcing fabric into the wet WeatherSTOP mixture and smooth from the center to the edge to avoid wrinkles. The reinforcing fabric must be continuous at all corners and lapped or abutted in accordance to Master Wall® Mesh data sheet requirements. Do not run mesh through control/expansion joints or accessories. The color of the mesh shall not be visible but a slight mesh pattern may be visible.

Clean Up—Tools and equipment can be cleaned with soapy water while the WeatherSTOP is still wet.

A Master Wall® Superior, Superior Elastomeric Plus or other approved Master Wall® finish must be used over the WeatherSTOP.

Surfaces exposed to the weather must be sloped (6:12 minimum).

Under certain conditions efflorescence on the surface during the cure process. This can be removed with a white vinegar solution.

If sanding or scraping are performed, ventilate work area and/or use a NIOSH/MSHA-approved respirator in accordance with our Safety Data Sheet.

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. ©2018 Master Wall Inc.®