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Coverage
50-60 square feet (4.6-5.6 square meters) - Adhesive & Standard Mesh
100-125 square feet (9-11.5 square meters) - Single Layer Mesh Only
30-110 square feet (2.5-10 square meters) - Double Layer Mesh Only
56 square feet (5.2 square meters) - Notched Trowel Only
Coverages are estimated and vary

Weight: 50lbs (22.7kg)

Working Time: 1 hour under normal room temerature and humidity.

Drying Time: 12 hours under normal room temperature and humidity.

Application/Storage Temperatures: 40F (5C) to 110F (43C)

Shelf Life: 1 year under normal conditions.

Approved Substrates
Exterior gypsum sheathing (ASTM C79)
Dens Glass Gold®
GlasRoc®
FiberBond®
Durock®
PermaBase®
Concrete
Brick
Masonry
Metal Lath
Others approved in writing

Application Procedure

Job Conditions - Air and substrate temperature for application of MBB 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 - Add 5 to 6 quarts (4.7-5.7L) of potable water to a clean plastic pail. Add the MBB slowly while stirring using a heavy-duty 1/2 (12.7 mm) drill at 400 - 500 rpm and a heavy-duty Mixer. Mix thoroughly to a homogenous consistency. Let the mixture stand for 3 to 5 minutes and then stir to a creamy consistency. Small amounts of clean, potable water may be added to obtain a workable consistency. Do not over mix. Excessive stirring may cause faster setting and reduced working time. Do not add accelerators or retarders to the MBB mixture.

Application

Adhesive application - Over gypsum substrates, apply the MBB mixture directly to the back of the insulation board using a 3/8 (9.5 mm) notched trowel with the ribbons no further than 3/4 (19 mm) o.c. Cover the entire back of the insulation board with full beads that stand out 3/8 (9.5 mm) from the insulation board.

Over non-gypsum substrates, you may use the above described notched trowel method or the �ribbon and dab method. Using a stainless steel plastering trowel, apply a 2 (50.8 mm) wide by 3/8 (9.5 mm) high ribbon of the MBB mixture around the entire perimeter of the insulation board. Place 8 dabs of the MBB mixture 3/8 (9.5 mm) thick by 4 (102 mm) in diameter approximately 8 (204 mm) on center inside the ribbon.

Immediately place the prepared insulation board on the substrate. Make sure that all edges of the insulation board are abutted tightly and that no MBB mixture gets into the board joints. Do not allow the MBB mixture to form a skin prior to placing the insulation board on the substrate. Do not apply the MBB mixture directly onto 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 MBB 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 MBB 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.

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