Rapid Set ® LEVELFLOR ® is an advanced hydraulic cement-based, polymer-modified self-leveling underlayment that can be used both indoors and outdoors. LEVELFLOR rapidly levels, maintains workability for 20 minutes and produces a flat, strong surface with high bond strength. LEVELFLOR is designed for fast track leveling applications and can be covered with finished flooring in 4 to 16 hours at 70°F (21°C), depending on the flooring type. This advanced underlayment can be applied from featheredge up to 2" (5.1 cm) thick or up to 5" (12.7 cm) thick when extended with aggregate. Contractors and engineers specify LEVELFLOR for self-leveling floor underlayment applications when a fast, durable and economical solution is required.