ARDEX S 48™ Rapid-Set Mortar / Mastic Hybrid is the most versatile tile setting material available for interior tile applications. A rapid setting polymer-modified, Portland cement based mortar that is ideal for fast-track installations of glass tile and back splashes. Can be used with porcelain, glass, ceramic, quarry, mosaics and most natural stone tile over all common substrates. Suitable for use in intermittent wet areas including residential bathrooms and kitchens. Its creamy, smooth consistency is similar to a pre-mixed mastic making it extremely easy to apply.