Mapei Ultraflex 2 Mortar

Mapei Ultraflex 2 Professional Polymer-Modified Thin-Set Mortar — 50 lb.

Mapei Ultraflex 2 is a professional-grade, single-component, high-performance, polymer-modified thin-set mortar for interior and exterior installations of ceramic, porcelain, and dimensional natural-stone tile. It has a high content of unique dry polymer, resulting in excellent adhesion to both substrate and tile. 

A step up from Ultraflex 1, Ultraflex 2 is the professional-grade choice for demanding residential and commercial tile installations. Polymer-enriched for high performance and deformability, with a smooth, creamy consistency for easy troweling. Mix with water only — no liquid additives needed. Plywood-compatible with improved adhesion over plywood substrates when properly prepared. 

For commercial applications, use on interior floor and wall installations and exterior floors. Available in gray and white — use white under light-colored stone and translucent tile. 

• Click here for Technical Data Sheet

What's the difference between Ultraflex 2 and Ultraflex 1?
Ultraflex 2 is professional-grade with a higher polymer content — better adhesion, deformability, and bond strength than Ultraflex 1. It's the right choice for demanding tile types, high-traffic commercial floors, and projects where performance margins matter.

Do I need to add a liquid admixture?
No. Ultraflex 2 is polymer-modified right out of the bag — mix with water only. No latex additive needed.

Can it be used outdoors?
Yes for most residential exterior applications and commercial exterior floors. For exterior commercial walls, use the Kerabond/Keralastic or Granirapid system instead.

Is it approved for plywood substrates?
Yes — meets ANSI A118.11 for use over properly prepared exterior-grade plywood.

What tile types does it work with?
Ceramic, porcelain, and dimensional natural stone. Avoid moisture-sensitive stone (green marble, some limestone and granite), agglomerate tiles, and resin-backed tiles — use an epoxy or urethane adhesive for those instead.

Which color should I use — gray or white?
White under light-colored stone, translucent marble, or light-bodied tile where gray mortar could show through the joints. Gray for most everything else.

Can it be used over OSB or hardwood flooring?
No — do not use over dimensionally unstable substrates including OSB, hardwood flooring, asbestos-containing materials, or metal substrates.

What ANSI standards does it meet?
Meets or exceeds ANSI A118.4E and ANSI A118.11 when mixed with water. ISO 13007 classification C2E.

Sku: 0060055