To finish strong you need a Superior Base Coat that can not only protect but waterproof the surface. Premium Guardian is formulated with extremely flexible waterproof polymers and fibered for improved tensile strength. Guardian embeds easily into Master Wall® mesh as part of a weather protection strategy.


VOC: <1% by Weight Manufacture Locations: 30058 • 77474 • 84651 Recycled Content: 0%

Packaging: 5 gallon (19L) pail

Pail Weight: 30 lbs (13.6 kg)

Coverage (estimated)
1/8” (3.2 mm) sealer: 45-50 sf (4-4.6 sm)

1/16” (1.6 mm) base coat : 89-100 sf (8.3-9.3 sm)

Working Time: 1 hour @ room temperature

Drying Time: 12 hours @ room temperature

Application Range: 40º-110ºF (5º-43ºC)

Shelf Life: 2 years

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 Guardian 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. Painted surfaces are not acceptable and must be removed.

Mixing – Thoroughly stir Guardian using a heavy duty 1/2” (12.7 mm) drill at 400 – 500 rpm and a heavy duty mixing paddle. Add Type I or I-II Portland cement to the pail of Guardian and fill to the top (approximately 20 lbs, 9 kg) and mix to a homogenous consistency. Let the mixture stand for 3 to 5 minutes and then stir to a creamy consistency. Up to 18 ounces (0.5L) of clean, potable water may be added to a half pail to adjust workability. Do not over mix as faster setting or reduced working time can occur. Do not add accelerators or retarders to the Guardian mixture.

Application – Adhesive/Sealer application – Apply the Guardian mixture approximately 1/8’ (3.2 mm) thick directly to the approved substrate using a stainless steel trowel. If used to adhere insulation, stipple the Guardian adhesive coat by pressing the trowel into the wet adhesive and then pulling it away from surface. Immediately apply the insulation board to the wet adhesive. Make sure that all edges of the insulation board are abutted tightly and that no Guardian mixture gets into the board joints. Do not allow the Guardian mixture to form a skin prior to placing the insulation board on the substrate.

For base coat application – All imperfections in the insulation board must be rasped flush and any gaps in the insulation board must be filled with slivers of insulation. Apply the Guardian mixture over the entire surface of the insulation board in a thickness greater than that of the reinforcing fabric being used (approximately 1/16” (1.6 mm) for standard mesh and 3/32” (2.4 mm) for Ultra Mesh). Immediately embed the reinforcing fabric into the wet Guardian 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® specifications. The color of the mesh shall not be visible but a slight mesh pattern may be visible.

For Sloped Surfaces—Embed reinforcing mesh in Guardian as noted in the base coat application. If Guardian is used on the sloped surface only, consider a skim coat of the wall base coat to equalize finish absorption and color. Minimum recommended slope is 1:2 and maximum run is 18” (0.46m) with two-layers of Standard Mesh. Consult Master Wall® and local code requirements for specifics.

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

Limitations – Guardian is not intended for water immersion.

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.®

F&M Mixing (Similar to Guardian)