The ARDEX LW™ System is a lightweight fill system for existing, indoor concrete slabs where the addition of dead load to the structure is a concern. It combines ARDEX technology with the addition of lightweight synthetic particles to create a deep fill that can be applied from a minimum of 3/4″ up to any thickness. This is followed by a 1/4″ coat of an ARDEX Self-Leveling Underlayment to create the ideal surface for the finished flooring installation.
Per inch of thickness, standard concrete adds 12 – 13 lb. of dead load per sq. ft. (58 – 63 kg / sq. m at 2.5 cm), while gypsum fills and Portland cement-based underlayments add 9 – 10 lb. / sq. ft. (44 – 49 kg / sq. m). Other traditional lightweight fill materials have substantially lower densities, but lack the integrity to serve as the substrate for a leveling course. Per inch of thickness, the ARDEX LW deep fill layer adds only 6.08 lb. / sq. ft. (29.7 kg / sq. m at 2.5 cm), and it dries and hardens quickly enough to allow the installation of the ARDEX Self-Leveling Underlayment layer after just one day.
Install the deep fill layer from a minimum of 3/4″ up to any thickness
Fast track – smoothing course applied after 16 hours
Combines ARDEX technology with advanced lightweight bead technology
Interior applications only
Deep Fill Layer
ARDEX P 51™ Primer
ARDEX K 520™ Self-Leveling Concrete Topping
ELEMIX® Beads (approx. 5 gal. / 19 L per bag of ARDEX K 520)
Coverage: A 50 lb. (22.7 kg) bag of ARDEX K 520 mixed at a 1:1 ratio (approx. 5 gallons / 19 L) with ELEMIX beads yields approx. 1 cu. ft. of fill
15 sq. ft. per bag at 3/4″ (2.8 sq. m at 18 mm)
Working Time: 5 – 10 minutes
Initial Set (ASTM C191): Approx. 15 minutes
Final Set (ASTM C191): Approx. 1 hour
Compressive Strength of the finished surface (ASTM C109/mod – Air cure only):
4,500 psi (316 kg/sq. cm) after 28 days if ARDEX V 1200 is used
5,300 psi (371 kg/sq. cm) after 28 days if ARDEX K 13 is used
5,500 psi (386 kg/sq. cm) after 28 days if ARDEX K 15 is used
Warranty: ARDEX L.P. Standard Limited Warranty applies. Also eligible for the ARDEX SystemOne™ Limited Warranty when used in conjunction with select HENRY® Flooring Adhesives.