Ardex Liquid BackerBoard Self-Leveling Underlayment — Smooth floors, Faster installs
Ardex Liquid BackerBoard is a self-leveling underlayment for interior wood and concrete subfloors, offering a faster and easier alternative to traditional backerboards. It eliminates the need for cutting, fitting, or metal lath mesh, even on wood subfloors, while creating a smooth, durable surface ready for tile and stone in as little as 6 hours.
Walkable in just 2–3 hours, it provides excellent coverage, installs up to 1 1/4″ thick, and is ideal for use over concrete, terrazzo, ceramic tile, epoxy, and for encapsulating in-floor heating systems.
Key Features
Replaces traditional backerboards for faster, easier installation
No lath mesh or additives required – even over wood subfloors
Walkable in 2–3 hours, install tile and stone in as little as 6 hours
Installs up to 1 1/4″ (32 mm) thick with excellent coverage
Easy to mix and pour – just add water
Ideal for encapsulating in-floor heating systems
Portland cement-based for strength and durability
Convenient prefill option over Ardex UI 740 Flexbone and other uncoupling membranes
Technical Data
Coverage Calculator
Installation:
Mixing Ratio: 6 quarts (5.7 L) of water per 50 lb. (22.7 kg) Bag
Approximate Coverage:
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)
Performance:
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
Calculator Ardex Liquid BackerBoard\n\n
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| SKU | AR LI.BACKER |
|---|---|
| UPC | 709850000979 |
| Weight (lbs.) | 50.0 |
| Non-Returnable | No |
| Manufacturer | Ardex |
| Manufacturer Part Number | 12438 |
