FAQ

Question: Do I still need to use lath with MBP and a self-leveling underlayment over plywood or OSB?

Answer: Yes, MBP does not reduce the deflection of the plywood or OSB between supports. Deflection can cause

the self-leveling underlayment to crack and the crack can propagate into the ceramic tile.

Question: Can MBP be used to prime Advantech for direct bond with a dry-set mortar?

Answer: No, Advantech is a subfloor material and requires a suitable underlayment for the installation of ceramic

and natural stone tile.

Question: Should I coat the back of resin-backed tile with MBP?

Answer: Yes, with many resin backings, this will improve the bond of the dry-set mortar. The MBP will bond to most

resin backings, but will not improve the bond of the resin backing to the tile. There are many different types

of resin backing and the only way to assure an adequate bond is by creating a mockup.

Question: Is MBP a waterproofing membrane?

Answer: No, while MBP has excellent water resistance, it is not considered a waterproofing membrane for ceramic

tile installations. It does not meet the requirements of ANSI A118.10. For these needs, CUSTOM offers

RedGard

Waterproofing and Crack Isolation Membrane.

Question: Can MBP be used in submerged applications such as fountains and swimming pools?

Answer: No, it is not designed for use in areas subject to prolonged water immersion. RedGard

Waterproofing and

Crack Isolation Membrane is recommended for preparing the tiled areas of fountains and pools.

Question: Can RedGard Waterproofing and Crack Prevention Membrane be applied to the dried MBP?

Answer: Yes, if waterproofing is required and there is a concern with adhesion to the surface, RedGard can be

applied to fully cured MBP.

Question: Can MBP be used to control moisture vapor emissions from a concrete slab?

Answer: No, MBP should not be applied to a damp slab with moisture vapor emissions greater than 5 lbs./day/1000

sq. ft. or 75% relative humidity. It will not control excessive moisture vapor emissions.

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