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by Ardex
SKU 12438P

Freight delivery rules and guidelines

ARDEX LIQUID BACKERBOARD® Self-Leveling Underlayment for Interior Wood and Concrete Subfloors - Full Pallet

Self-Leveling Underlayment for Interior Wood and Concrete Subfloors is a pourable blend of Portland cement and other hydraulic cements that replaces traditional backerboards for a faster, easier, seamless installation of tile and stone over wooden subfloors, concrete, terrazzo, ceramic tile and epoxy, eliminating the need to cut, fit, glue and fasten. ARDEX Liquid BackerBoard DOES NOT REQUIRE LATH MESH, even when used to smooth and level wood subfloors. Tile and stone can be installed in as little as 6 hours. ARDEX Liquid BackerBoard is also suitable for the installation of engineered wood plank and laminate floor coverings and for encapsulating in-floor electrical heating systems.


  • Smooths subfloors prior to the installation of tile, stone and wood flooring
  • Does not require lath mesh or additive
  • Walkable in 2 – 3 hours
  • Install tile and stone flooring in as little as 6 hours
  • Easy to mix – just add water
  • Installs up to 1 1/4″ (3.1 cm) thick
  • Excellent coverage: 65 square feet at 1/8″
  • Ideal for encapsulating electrical in-floor heating
  • Portland cement based
  • Use as a convenient, fast and easy prefill option over ARDEX UI 740™ FLEXBONE® and other approved uncoupling membranes


  • SystemOne
  • Tested in Accordance with ASTM C1708


Mixing Ratio:

6 quarts (5.7 L) of water per 50 lb. (22.7 kg) Bag


32.5 sq. ft. per bag at 1/4” (3 sq. m at 6 mm)

65 sq. ft. per bag at 1/8’’ (6 sq. m at 3 mm)

*Coverage will vary depending on the texture of the surface being smoothed.


  • Flow Time: 10 minutes
  • Compressive Strength (ASTM C109/mod – Air cure only): 3,000 psi (210 kg/sq. cm) at 28 days
  • ASTM C627 Rating (Robinson-Type Floor Tester): Classified as extra heavy
  • Flexural Strength (ASTM C348): 700 psi (49 kg/sq. cm) at 28 days
  • Walkable: 2 – 3 hours
  • Install Flooring and Waterproofing: See Installation of Flooring and Waterproofing section in Technical Data
  • VOC: 0
  • Packaging: 50 lb. (22.7 kg) bag
  • Storage: Store in a cool, dry area. Do not leave bags exposed to sun.
  • Shelf Life: 1 year, if unopened
  • Warranty: ARDEX L.P. Standard Limited Warranty applies