Flex Set Mortar (Premium)

Multicoat’s Flex Set Mortar is a premium polymer modified mortar adhesive used to set tile, glass tile, stone, brick, brick veneer, and rock.

PACKAGING/COLOR: FLEX SET MORTAR is furnished in Grey or White color , packaged in 50-lb bags.

STORAGE: Store bags in a cool, dry location. Store away from direct contact with the ground or concrete. Protect from weather and other damage. Shelf life is approximately 24 months in unopened bags.

  • Flexible to Help Reduce Cracking in Tile 
  • Aggressive Bonding Strength 
  • Just Add Water 
  • Suitable for Submerged Applications 
  • Bond Non Porous Tile such as Porcelain 
  • Environmentally Friendly
  • ANSI A118-1,  A118-4,  A118-11


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More Information

Flex Set Mortar (Premium)


Size                 Trowel Size            Coverage
Up to 8”        1/4” x 1/4” x 1/4”        Sq. Notch 90-100 Sq. Ft/Bag
8” to 12”        1/2” x 1/2” x 1/2”        Sq. Notch 60-70 Sq. Ft/Bag
12” +              1/2” x 1/2” x 1/2”        Sq. Notch 45-50 Sq. Ft/Bag

Application & Use:

Be sure mixed material is consistent from batch to batch. Apply FLEX SET MORTER to substrate with flat trowel. Use a properly sized notch trowel to insure proper coverage and spread of material under tiles. Work placed FLEX SET MORTAR with notched trowel to create rows of adhesive to proper thickness for item being placed. Press tile firmly in place, moving back and forth to insure a proper set. Adjust tile quickly and then gently tap into place with rubber mallet or beating block until flush with other units. Periodically pull up a tile or stone and check the back to insure proper adhesive coverage. If mortar has already taken its set under the lifted tile, remove mortar and replace with fresh FLEX SET MORTAR. Placed FLEX SET MORTAR can be a total of 3/8” thick once item has been set and tamped into place.

MIXING: FLEX SET MORTAR is to be field mixed with clean potable water and mechanically mixed to desired consistency based upon scope of application. Add approximately 6-1/2 quarts of water into mixing container. Slowly pour the contents of the bag into the mixing water. Mix until a firm, workable consistency is achieved. If more water is needed, add small amounts and continue to mix until consistency is achieved. Let the mixture slake or stand 5 to 10 minutes, then stir again and use. Stir occasionally but do not add more water. Desired consistency should be trowel ridges should stand without slumping. Do not exceed a total volume of 1.5 gallons of water for each 65-lb bags.

CURING: Curing time will vary due to weather conditions, thickness, substrate absorption, etc. Material should be protected from weather elements and foot traffic for a minimum of 24 hours.

EXPANSION JOINTS: Provision for movement (expansion joints and control joints) and other changes of plane in all installations are required. Do not bridge expansion or control joints. Those joins should be brought up through the work and filled with a suitable caulking.

Flex Set Mortar (Premium) Instructions SDS


  • Flexible to Help Reduce Cracking in Tile
  • Aggressive Bonding Strength
  • Underwater Application
  • Just Add Water
  • Suitable for Submerged Applications
  • Swimming Pools and Spa
  • Bond Non Porous Tile such as Porcelain
  • Environmentally Friendly
  • ANSI A118-1, A118-4, A118-11