The Grout Really Makes the Tile



 November 24, 2020. 5:55 PM

In planning Tile & Stone installations, we tend to focus much time and effort poring over which tiles to choose for our walls and floors. Ceramic, porcelain or stone? Large-format or traditional small? As important as the choice of these building materials is, the choice of grout should take equal consideration, to ensure you get the long-lasting look you want. MAPEI has been at the forefront of trends in grouts throughout our 80-plus year history. So what’s new in grouting these days?

Choosing the Right Grout

Building on our existing color palette consisting of dozens of classic choices, four important developments from recent years stem from the fruits of our research to deliver high-performance grouts:

  • Grouts formulated to provide iridescent effects.
  • Grouts that not only prevent efflorescence, but eliminate efflorescence, and provide resistance against staining and discoloration.
  • Ready-to-use grouts (RTU grouts) in traditional colors.
  • RTU grouts customized to match any color desired.

What is Iridescent Grout?

MAPEI_Flexcolor_3D_.5gal_[.75gal]_angle_rgbIn scientific terms, iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. A good example of this can be seen in the swirling surface of soap bubbles.

It can be achieved using MAPEI Flexcolor 3D professional-grade, ready-to-use (RTU) translucent specialty grout. It is offered in 10 designer colors with translucent characteristics that not only reflect but also refract light. This allows the grout to transition in color to complement the tile color.

MAPEI Flexcolor 3D is also formulated for commercial and residential interior installations of porcelain, ceramic, glass and natural-stone tiles. Plus, the dense surface structure of the grout helps to prevent water-based stains on the grout surface. It is formulated with the latest innovation in recycled glass-bead aggregate, which ensures color consistency, ease of cleanability and improved workability. In addition, this grout can be used on sensitive tile surfaces once tested, requires no sealer and cures naturally from evaporation.

What is Efflorescence?

Efflorescence is a fine, white, powdery substance, the result of water-soluble salts that form on the surface of typical Portland-cement-based materials. Efflorescence occurs when excessive moisture draws some of Portland cement grout’s mineral salts to the surface - a process known as hydrostatic pressure.

The result of an efflorescence problem is the development of a white residue on the grout after it dries. The integrity of the grout itself is not compromised, but the residue can be stubborn, and trying to clean efflorescence is not always easy. While efflorescence removal is possible with products like MAPEI’s UltraCare Acidic Tile & Grout Cleaner, efflorescence prevention is even better.

What Grouts Prevent or Eliminate Efflorescence Issues?

UC_Plus_FA_Image There is no need to remove efflorescence when your grout can prevent it from occurring in the first place. Modern research and technology have created alternatives to Portland-cement grout, thus eliminating the salt deposits that cause the white, powdery efflorescence on the masonry surface.

For example, MAPEI offers a fast-setting cement (calcium aluminate) grout named Ultracolor Plus FA. By incorporating MAPEI’s High-Hydrated Cement Technology (HCT™), there is no resultant efflorescence, nor color inconsistency. Along with offering higher polymer content, HCT reduces absorption and increases stain resistance when compared with standard-performance cement grouts.

ultracolor plus maxPreventing efflorescence is also possible with another one of our latest grout additions, Ultracolor Plus Max,

(White or Black), for which the use of HCTallows us to confidently define it as the whitest white and blackest black of any grout to be found on the market. These grouts are classified as ANSI 118.7 or high-performance grouts. They cure more rapidly, and are not affected by moisture conditions, which also makes them more color-consistent and allows for earlier foot-traffic.

Another MAPEI innovation found in our high-performance grouts is our DropEffect technology, which reduces surface absorption, helping to repel water, dirt and grime from penetrating grout joints. Essentially, any water-based spills on the cured grout bead up.

RTU (Ready-to-use) Grout


MAPEI_Flexcolor_CQ_1gal_angle_rgbThanks to MAPEI’s extensive research and development, RTU grouts like MAPEI Flexcolor CQ provide a single component, ready-to-use acrylic grout for both interior and exterior tile installations.

It takes advantage of MAPEI’s BioBlock® technology for mold and mildew resistance, and its non-porous composition helps to prevent water-based stains by providing water repellency to the grout surface.

MAPEI Flexcolor CQ is formulated with quartz aggregate, which ensures:

  • Color consistency
  • Easy cleaning
  • Improved workability

in addition, this grout can be used on sensitive tile surfaces once tested, requires no sealer, and cures naturally from evaporation of the low level of water in the formulation. comparison testing versus traditional portland-cement grout has verified that <em>mapei flexcolor cq</em> is 30% more cost-efficient (based on typical rates of installers) and requires 65% less time to install.


MAPEI’s New Custom-Colored Grout

20-3223 SM_MAPEI_CA_MAPEI_Flexcolor_Design

The latest innovation on the market is one that provides an almost limitless range of color options: MAPEI Flexcolor Design. This RTU specialty grout also incorporates BioBlock technology, plus it uses personalized computer color-matching to allow you to “design your own color,” – any color.

How do we do it? The process is simple: Just provide your MAPEI representative with an opaque color sample swatch measuring at least 2" x 2" (5 x 5 cm)*. Using the swatch, we can easily create a perfect color match for your MAPEI Flexcolor Design grout using our cutting-edge color-measuring and color-matching technology.

* Note: Unacceptable color samples: Textiles, metallics, phosphorescent (glow-in-dark) and fluorescent. This product is exclusively for National Brand Accounts and Commercial Projects. For complete information on samples and ordering, contact your local MAPEI Architectural Representative.


Colors can also be chosen from one of these existing fan decks:

  • MAPEI grout colors
  • Benjamin Moore
  • Sherwin-Williams
  • PPG
  • Glidden
  • Behr
  • Hugo Boss Trend Colors
  • Florida Paints
  • BASF MasterProtect
  • Pantone
  • Federal Standard 595C
  • RAL colors
  • NCS (Natural Color System)
  • Kraft Paints (UK)

MAPEI Flexcolor Design is formulated with the latest innovation in recycled glass-bead aggregate, which ensures color consistency, ease of cleanability and improved workability. Like MAPEI Flexcolor CQ, this grout can be used on sensitive tile surfaces once tested, requires no sealer and cures naturally from evaporation.

MAPEI’s Traditional Grout Colors

couleur coulis

Those looking for traditional grout colors in out-of-the-box solutions can still find dozens of choices in the classic MAPEI grout color palette, categorized into groups based on the desired effect:.

  • Serene
  • Traditional
  • Natural
  • Romance
  • Glamour
  • MAPEI Flexcolor 3D translucent grout (iridescent effect)

The other colors may also be applied to our premium polymer-modified Portland-cement tile grouts: Keracolor S pre-blended, sanded tile grout for joints from 1/8" to 5/8" (3 to 16 mm), and Keracolor U pre-blended unsanded tile grout, for joints from 1/16" to 1/8" (1.5 to 3 mm).

What’s Next?

With MAPEI, there is always more innovation in the pipeline. Our research scientists work within a global network comprising 31 centers, with our Corporate Research Centre in Milan acting as a hub to coordinate the activities of all the other centers and as a central analysis laboratory.

The centers, all equipped with cutting-edge equipment, collaborate continuously with universities and scientific and industrial research institutes. To stay on top of all MAPEI news and innovations, scroll down and create your free MyMAPEI account at the bottom of this page, or from

Frequently Asked Questions

On what porous building materials can efflorescence occur?

Efflorescence is a white, powdery substance that can be found on a number of surfaces, and not just grout or grout admixtures. Any porous surface or building material that contains some form of mineral salts can experience efflorescence, including brick, wood, cement, clay, mortar joints, pavers, stucco and others. Water absorption can occur in porous materials like those described above in a process referred to as “capillary action,” in which the material ends up drawing in salts and eventually resulting in efflorescence.

How can I remove efflorescence and soluble salts?

Preventing efflorescence should be the goal, but if you have noticed some white powdery substance on your porous construction materials, it can be removed. With any luck, the only cleaning solution you need is water, since efflorescence salts are water soluble. But for the tougher jobs, and to keep tiles & stone set with Portland-cement grouts from developing any further issues, call our Technical Services team at 1-800-361-9309 to recommend the right UltraCare product for your exact needs.

Can I use muriatic acid to clean efflorescence?

Sometimes when water evaporates from certain porous materials, it can create an extra-difficult efflorescence to remove. You can try using a mixture of water and household vinegar to clean it off, but if you need something a little more powerful, MAPEI offers a phosphate-free solution: UltraCare Acidic Tile & Grout Cleaner.


Products mentioned in the article

Keracolor S
Keracolor S
Premium Sanded Grout with Polymer Keracolor S is a premium-grade, pre-blended, polymer-modified sanded Portland-cement tile grout that…
UltraCare Acidic Tile & Grout Cleaner
UltraCare Acidic Tile & Grout Cleaner
UltraCare Acidic Tile & Grout Cleaner is a highly concentrated acidic cleaner formulated to remove cement grout haze, mortar residue,…
MAPEI Flexcolor 3D
MAPEI Flexcolor 3D
Stain- and chemical-resistant grout formulation with no sealing required Easy cleanability, color consistency and improved workability …
MAPEI Flexcolor CQ
MAPEI Flexcolor CQ
Ready-to-Use Grout with Color-Coated Quartz MAPEI Flexcolor CQ is a professional-grade, ready-to-use specialty grout for precision…
MAPEI Flexcolor Design
MAPEI Flexcolor Design
MAPEI Flexcolor Design is a professional-grade, ready-to-use (RTU) specialty grout that allows you to “design your color,” any color. MAPEI…
Ultracolor Plus Max
Ultracolor Plus Max
Ultracolor Plus Max is an ultra premium, fast-setting, polymer-modified, nonshrinking grout that offers rich and vibrant colors with…
Ultracolor Plus FA
Ultracolor Plus FA
Rapid-Setting, “All-in-One” Grout Replacement for Sanded and Unsanded Grouts Ultracolor Plus FA – with DropEffect ™ technology and CO 2…
Keracolor U
Keracolor U
Premium Unsanded Grout with Polymer Keracolor U is a premium-grade, pre-blended, polymer-modified unsanded Portland-cement tile grout that…





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