Professional, Lightweight Mortar with Polymer for Large and Heavy Tile MAPEI Ultralite Mortar Pro is a professional-grade, lightweight, single-component thin-set mortar that can also be used for large-and-heavy-tile and non-sag applications. This polymer-modified mortar is formulated with Easy Glide Technology™ for ease of application. MAPEI Ultralite Mortar Pro ’s unique Ultralite Technology™ provides twice the coverage of a standard thin-set mortar per pound/kg and contains more than 20% recycled content.