ARDEX P 4™ Pre-Mixed, Rapid-Drying, Multipurpose Primer is a pre-mixed, single-component, rapid-drying, multi-purpose primer for interior and exterior use. The consistency of ARDEX P 4 has been formulated to virtually eliminate dripping and splashes. Use prior to the installation of ARDEX Tile & Stone mortars and ARDEX self-leveling underlayments. ARDEX P 4 produces a textured surface and can be used on smooth surfaces to create a bond. It is the ideal primer for use in areas that may become damp or wet, such as kitchens, bathrooms, porches, etc.