ARDEX Liquid BackerBoard, Portland Cement-based Self-Levelling Underlayment for Encapsulating In-floor Electrical Heating Systems, Interior Wood and Concrete Subfloors - 50 lb (22.7 kg) Bag (12438)

Product Features:

• Easy Pour & Long Working Time: ARDEX self-leveling underlayment has an easy-to-use, pourable formula with long working time for leveling subfloors before tile, stone, wood, laminate or LVT.
• Flat & Even Floor Preparation: This high-performance underlayment creates a flat, even surface ideal for bathroom tile, kitchen tile, basement floors, and whole-home flooring preparation.
• 15-Minute Correction & Healing Time: Imperfections and surface irregularities can be corrected within 15 minutes after pouring, with healing time helping reduce lippage under tile and stone.
• Up to 1/2" Single-Pour Application: ARDEX Liquid BackerBoard applies up to 1/2" thick in a single pour and works as a prefill over uncoupling membranes and electric heated floor systems.
• Flowable Gap & Dip Elimination: Its flowable consistency eliminates gaps, dips, and uneven spots while creating a smooth, seamless surface for tile, stone, wood, and resilient flooring.
• No Lath Mesh or Additives Required: This self-leveling underlayment does not require lath mesh or additives, even over wood subfloors, and mixes easily with water for simple preparation.
• Radiant Heat Cable & Mat Encapsulation: It is ideal for encapsulating electrical in-floor heating systems such as radiant heat cables and mats, improving heat distribution and tile adhesion.
• Wide Substrate Compatibility: Suitable over concrete, cement backerboard, exterior-grade plywood to 24" o.c., ceramic tile, pavers, brick, stone, terrazzo, sheet vinyl, and prepared floors.
• Residential, Commercial & Light Industrial Use: ARDEX Liquid BackerBoard is extremely versatile for residential, commercial, and light industrial flooring projects, including remodels.
  

Product Description:

ARDEX Liquid BackerBoard self-leveling underlayment is engineered for interior wood and concrete subfloors, offering a faster, easier alternative to traditional tile backerboards. Formulated from Portland cement and advanced hydraulic cements, this pourable underlayment replaces cutting, fitting, gluing, and fastening board materials, allowing installers to create a seamless, monolithic surface ideal for tile, stone, wood, and resilient flooring installations. It is specifically designed to flatten and level uneven subfloors in preparation for ceramic tile, porcelain tile, mosaic tile, marble tile, granite tile, shower tile, stone tile, and large-format tile installations.

ARDEX Liquid BackerBoard does not require lath mesh, even over wood substrates, significantly reducing labor time while delivering industry-leading strength, crack resistance, and bond performance. Tile and stone can be installed in as little as 6 hours, making it a high-efficiency option for contractors, renovators, and DIY professionals. The product is also suitable for engineered wood plank flooring, laminate flooring, luxury vinyl plank, and floating floor coverings. Additionally, it is designed for encapsulating in-floor electrical heating systems, providing a smooth, protective surface that enhances radiant heat performance.

This self-leveling underlayment can be used for home décor upgrades, bathroom remodels, kitchen flooring, living room renovations, basements, and commercial or industrial applications where a flat, durable substrate is essential. Its user-friendly design makes installation straightforward and predictable, ensuring professional-grade results that improve aesthetics, tile alignment, and long-term flooring durability. It can also be applied over properly prepared terrazzo, existing ceramic tile, and epoxy substrates. It also works as a fast prefill option over ARDEX UI 740 FLEXBONE and other approved uncoupling membranes for tile membrane underlayment preparation.

One bag provides exceptional coverage, replacing three sheets of traditional backer board, making it a cost-effective and efficient solution for large and small projects. Ardex Liquid BackerBoard mixes easily with just water and requires no additives. It can be installed up to 1 1/4" (3.1 cm) thick and becomes walkable in 2–3 hours. With excellent coverage of approximately 65 sq ft at 1/8", it is the ultimate flat surface for tile, stone, and large-format flooring installations. For consistent mixing, use 6 quarts (5.7 L) of water per 50 lb. (22.7 kg) bag; at 1/4" thickness, one bag covers approximately 32.5 sq ft (3 sq m), depending on surface texture.

For demanding flooring preparation, Ardex Liquid BackerBoard delivers a 10-minute flow time and reaches a compressive strength of 3,000 psi at 28 days under ASTM C109 modified testing. Its 28-day flexural strength reaches 700 psi under ASTM C348, while ASTM C627 Robinson-Type Floor Tester performance is classified as Extra Heavy. These performance characteristics support a strong, durable floor underlayment for professional tile and stone installations where dependable load performance, surface stability, and long-term flooring durability are important.