ARDEX GS-4™ is a self-leveling underlayment used to repair and finish above grade gypsum and wood substrates prior to installing new floor covering. Pourable or pumpable when mixed with water, it seeks its own level and produces a smooth, flat, hard surface.

ARDEX GS-4 can be installed up to 2” (5 cm) neat, or 5” (13 cm) with aggregate, to achieve the desired flatness tolerance, and hardens and dries quickly without shrinking, cracking or spalling. It can be walked on after 3 hours, and floor covering can be installed as soon as the underlayment has dried sufficiently for the floor covering selected. The drying time is a function of temperature, humidity and the thickness at which the material is applied. ARDEX GS-4 also can be used over gypsum and wood floors that employ the use of hydronic or low-voltage electrical in-floor heating systems.