What is Mortar? What Makes a Mortar “Super”?


Mario Taglienti

 December 8, 2022. 8:25 PM

MortarsNavigating through the sea of mortars nowadays can make choosing the right binding material into a daunting task. Mortars have become extremely specific, compared to when I first started installing tiles over 30 years ago. All I knew about mortar mix was that it was made with Portland cement mortar and sand and that it was sufficient for the building materials that we had to install at that time. The largest tile back then was 8" x 8" (20.3 x 20.3 cm) and was ceramic-based.

With time, the first polymer-modified mortar was introduced, and I didn’t really know why I needed a building material composed of polymers. Tiles kept changing as well, becoming larger and larger, and the composition changed from ceramic to porcelain. It was obvious that the types of mortars were just following the trend of the tiling, masonry & construction industry.

The Evolution of Mortar in Construction

Necessity is the mother of all invention, and this adage is particularly true for tiling and masonry materials. So, I started taking a better look at the different mortars once the style of tiles that my clients were choosing had become significantly diversified.

Today, gauged porcelain tiles can be as large as 5 x 10 ft. (152 x 304 cm) and are only 3/16" (4.5 mm) thick. By the way, that’s about half the thickness of a standard 24" x 24" (61 x 61 cm) porcelain tile. The majority of the projects that I worked on in those days included showers and bathrooms. Installers today find clients wanting to install 16" x 32" (40.6 x 81.3 cm) tiles on a shower wall with pebbles on the shower floor and 32" x 32" (81.3 x 81.3 cm) floor tiles outside the shower. Most installers prefer to use only one type of mortar for all areas, so with such a wide variety of styles and sizes, the need has arisen for one mortar that works perfectly to handle these differences.

Mortars of various kinds have been used for thousands of years, from the earliest versions of lime mortar and mud mortar to gypsum mortar for brick or stone masonry to the most advanced mortars for tile installation. For installers who want to simplify their lives and rely on a single, complete building material for their tiling needs, that mortar is MAPEI’s Keraflex Super.

When it was first introduced, I didn’t know anything about this new mortar and needed more information so I could make an educated recommendation about whether installers could use this mortar over other mortars that they’ve used in the past.

How Does Mortar Set? What Makes Keraflex Super so Different?

Keraflex SuperI researched the mortar and found that this is a premium, extra smooth, polymer-enriched mortar with no vertical slip and with non-sagging capabilities. The feature that most interested me was that it has no vertical slip, even with quite large tiles on shower walls. It also offers an extended working time which, when one works with large tiles, is very important. This product’s open time is 30 to 50 minutes, and the pot life is around 4 hours!

The next obvious question was, “How long before grouting the tiles?” I assumed that because the extended workability of the mortar was so long, the wait time must be extended before grouting. However, with Keraflex Super, someone would be able to grout the walls after 8 to 16 hours and the floors after 24 hours.

Being the old school installer that I am, I had to see this firsthand, so our team tested Keraflex Super in our facility. As I would have expected, the mortar performed exactly as promised. Keraflex Super has a high content of a unique dry polymer, resulting in excellent adhesion to the concrete structures, substrates and tile, with enhanced resistance to freeze/thaw environments. This unique consistency allows adjustability when used with lippage control systems. Keraflex Super mortar is a “go-to mortar” whenever you need a mortar for large tiles, especially in showers.

Learn More About the Keraflex Family of Mortars

See how preparation and execution go hand in hand to obtain the best possible solution to any situation. Click here to learn more about the Keraflex family of mortars for large-and-heavy tiles.


Mario Taglienti

Mario Taglienti

Mario brings years of knowledge and expertise in his role as a Technical Support Advisor at MAPEI. He began working in the industry when his family started a flooring business back in 1976. Mario eventually went on to operate his own successful flooring company in Pennsylvania for 15 years before relocating to South Florida.


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