From the convenience and ease of pre-mixed grouts to the tenacious grip of mortars for large and heavy tile, we sat down to discuss the latest advancements in grouts and mortars with those that know them best. Included in the discussion are Mike Micalizzi, senior director, technical services at Custom Building Products; Loren Doppelt, market manager at H.B. Fuller Construction Products; Arthur Mintie, Laticrete’s senior director of technical services; Jim Whitfield, MAPEI’s technical services manager; Brett Mauney, Merkrete technical manager; Alan Kin, technical sales manager for Texrite; and Michelle Swiniarski, market manager, tile and stone installation systems for Bostik.

Why are pre-mixed grouts becoming more popular?

Micalizzi: A pre-mixed grout supplies the solution to most of the major issues with cement and epoxy grout use. On-site mixing of cement grouts can be challenging for most installers and often water is not measured accurately. Secondly, the grout is commonly over-washed during the cleaning stage which produces soft and discolored grout. Washing grout too early can definitely produce the same results. On the other hand, epoxy grouts can be a challenge to spread and clean properly. These ready-to-use products simplify the job for the finisher and help make it more error-proof. Pre-mixed grouts minimize waste and some can be cleaned immediately, saving mixing, slaking and setting up time on each project.

Doppelt: With pre-mixed grouts, there is no need to worry about carrying a drill, water, measuring bucket, or mixing bucket to the jobsite. In addition, they can be resealed after opening for future use. With a cementitious grout, once it is mixed it must be used right away.

Whitfield: The color consistency of pre-mixed grouts offers a huge benefit, in addition to the convenience of opening a pail and starting to use the grout. This also allows the grouting process to go faster—no mixing, no slacking; just install and clean up.

Mauney: Contractors and homeowners are moving toward these types of grouts primarily due to ease of use and stain resistance. A homeowner does not have to worry about stains and a contractor does not have to come back to seal the grout, so it is a win-win for everyone.

Mintie: Pre-mixed grout can also be less expensive when used for smaller jobs because these products can usually be purchased in small quantities. Any leftover grout can be saved and then used on other projects – significantly reducing waste.

Kin: “More popular” to use premixed grouts have turned into “more practical” to use.

Swiniarski: Pre-mixed urethane grouts are popular because it offers the best of all worlds.

What are some other benefits of pre-mixed grouts?

Micalizzi: They can offer exceptional stain resistance with no sealing required. Custom’s Single Component Fusion Pro Grout is guaranteed to be both color-perfect and stain-proof. These lower-maintenance benefits sell themselves to designers, developers and end-users alike.

Mintie: Some pre-mixed grouts already contain materials like latex or urethane, which can help improve adhesion and eliminates the need for sealing.

Doppelt: With the popularity of glass and metallic tiles, specialty pre-mixed grouts offer a reflective effect which can accentuate the tile’s beauty.

When should a professional installer choose a pre-mixed grout over the traditional variety?

Doppelt: It really comes down to installer preference in most cases. Pre-mixed grouts can be particularly useful when doing smaller installs like backsplashes, especially when the entire container of grout is not used. In this case, unused grout in the container can simply be resealed and brought to another jobsite.

Kin: The optimal time to choose a pre-mixed grout occurs when the job would otherwise require the use of a grout sealer for stain protection. That’s when the professional installer and the client/owner can reap the maximum benefits.

Micalizzi: On practically every installation! Examples of some exceptions are fully immersed applications, very wide or deep grout joints such as seen with pebble tile, when soft or porous tiles are used, or when high chemical resistance is required on the project. Always check with the grout manufacturer for any specific limitations.

What technological advancements has the mortar category seen for installing large and heavy tile (LHT)?

Whitfield: Mortars need to meet the coverage requirements for the installation in question. This is where thixotropic [meaning it is viscous when left alone but becomes more fluid when stirred, agitated or otherwise stressed] large and heavy tile mortars fit in. MAPEI has a wide range of thixotropic LHT mortars that exceed large and heavy tile installation requirements with products that perform multiple functions. Their formulations allow MAPEI’s LHT mortars to be used as both standard thin-set mortars and large and heavy tile mortars with non-slump performance.

Micalizzi: Mortars have gained in thixotropic qualities to prevent slipping and sagging on walls. Formats that are larger than 15” on any side and/or weigh 10lbs/sf can be held in place without spacers or mechanical fasteners and bond strengths can exceed 600psi vs the standard mortars at 200psi. Mortars designed for use with large and heavy tile and meeting ANSI A118.15 (or A118.15 T for wall installations) should be used with these tiles.

Mauney: Merkrete has answered the demand of these larger porcelain tiles and natural stone products with a series of LHT mortars. Introduced over the last few years, LHT (formerly known as medium-bed) products such as 855XXL, 856 XLF and 820 Merlite feature non-sag and non-slip properties for floor and wall installations. Recently, Merkrete launched a new series of mortars featuring DLT—Dustless Technology. Specifically, 720 Dustless LHT Mortar is designed for large and heavy tiles.

Mintie: Laticrete recently introduced LHT Plus, a polymer-modified large and heavy tile mortar specifically formulated to provide a one-step installation for large-format ceramic tile, porcelain tile and stone on floors. In addition to providing a superior bond that withstands the trials involved with installing large and heavy tile, LHT Plus offers a smooth and creamy consistency for ease of use and can be built up to 3/4 in. (19 mm) thick without shrinkage. LHT Plus also exceeds ANSI A118.11 requirements and can be used over Exterior Glue Plywood (EGP) without the use of an additive.

Kin: Grout and mortar manufacturers are constantly evolving and adapting to client and installer needs. Increased offerings for large and heavy format tiles in turn create more demand for modified/new versions of mortars to assist in the installation. With more widespread selection of large and heavy tile, there will be more emphasis placed on augmenting bonding mortars with non-sag (for walls) and non-slump (for floors) properties.

Doppelt: Finding a mortar that gives you great handling properties, better slip and slump capabilities, long open time and bucket life, and a fast set time might have seemed impossible in the past, but this new generation of mortars combines all of these qualities in a single mortar.

What does an installer need to know when working with these types of products?

Micalizzi: Even though these mortars hold the tiles in place easily, proper trowel size, adequate mortar coverage and preventing voids behind the tile is necessary. Spot bonding is not acceptable. For more information on proper troweling techniques per industry standards, watch the National Tile Contractors Association (NTCA) video on YouTube about installing large format tile the right way—“Trowel & Error,” which is available in both English and Spanish.

Mauney: Following the manufacturer’s recommendations for mixing these products is key. For example, proper slaking (waiting) after mixing for the recommended amount of time can make or break the performance of these types of mortars. Most of the non-sag mortars can be used not only for walls, but also for floors as a thin-set or medium-bed set.

Kin: The toughest hurdle of large and heavy tile installations will be to overcome traditional habits including using traditional thin-set mortars. Today’s professional installer will need to merge the LHT mortars, different notch trowels, lippage tools and techniques with all levels of the installation team (materials purchasers, estimators-bidding, installers, sales and management members). In time, this will become part of the standard operation procedure (SOP) for the professional tile installer and will no longer be approached as a special, “one of a kind” job situation.

What technology advancements for grout and mortar are available for thin (gauged) tile?

Mintie: Gauged porcelain tile panels can be as large as 10 ft. by 5 ft. and are half the thickness and weight of conventional tile. Installing this material requires special training and equipment, as well as a high-performance adhesive that offers an extended open time, high bond strength, excellent workability and proper curing parameters.

Micalizzi: Adhesives and mortars that have an extended open time and are creamy and easy to handle are recommended for these large formats. This adds an “E” (extended working time) to the ANSI A118.15 material standard. Lightweight mortars that are easier to mix, carry and apply are also important, as these 10-foot tiles are already time-consuming to maneuver and install.

Whitfield: I think gauged porcelain tile panels/slabs and large-format tile have started to be used where tile has not been popular before. We are seeing a large growth in walls and exteriors. These substrates must be flat and within the ANSI tolerances; they commonly require additional patches, renders and mortar beds to accommodate these needs. MAPEI started receiving requests for wall repair materials that would work from more than 1 in. and down to 1/8 in. on cement, masonry, cement board and properly prepared drywall. The launch of MAPEI’s Planitop 330 Fast cementitious rendering mortar has been a huge success with installers for its “wall-friendly” characteristics.

Swiniarski: In response to the newer tile category of thin gauged porcelain panels Bostik introduced a new-technology product named Bosti-Set Thin Porcelain Tile Panel Adhesive & Sound Reduction Membrane which allows faster, safer and more durable installations of these panels. Bosti-Set offers the patent-pending Tenirex Polymer Technology which provides Bosti-Set with instant grab and holding power. Because all that is needed is a single coat of adhesive on the back of the panel itself, installation on walls is much faster and easier than using mortars. Outstanding workability allows the panels to be repositioned for up to 30 minutes with no slip or sag.

Kin: Mortar manufacturers have not stopped in their quest to produce specific installation mortars for these evolving tile types. The thin-gauged tile type is new and developing, and so are the mortars. These mortars have extended wet tack times or semi-fluid paste consistency to allow for better contact and reduce air voids/hollow spots under thin-gauged tile.

What does an installer need to know when working with gauged tile?

Mauney: Understanding thin-gauged tiles are very important as these tiles can break during installation and are quite costly to replace. So the right setting material, tools and manpower are essential for proper installation.

Doppelt: One of the most important things to remember when working with gauged tile is to know your jobsite. You need to consider how to safely deliver the tile from the loading dock to the jobsite. Don’t assume that the tile will fit up the stairs, around tight corners or in an elevator. It is also important to have the right equipment for the job. Due to the large size of the tiles, they cannot be installed with traditional square notch trowels that require movement to collapse the ridges. Instead, specialized trowels, such as a Euro trowel, are designed with notches that allow the ridges of the mortar to collapse with minimal effort.

Micalizzi: Training and special equipment are absolutely required before your first project begins! Refer to ANSI A137.3 for details on tile standards and ANSI A108.19 for installation standards and contact the NTCA for hands-on training near you.

Anything else you want to add?

Mintie: Over the last five years, consumers have become more committed to long-term sustainable living and prefer to identify the impact installation materials will have on the environment. In turn, the tile and flooring industry has seen a significant increase in the quantity and quality of green products in order to meet today’s regulatory and consumer standards.

With this shift, new grouts and mortars are commonly made from recyclable, sustainable materials and emit low VOCs. These new products also are designed to meet or exceed many regulatory requirements including Health Product Declarations (HPDs), Environmental Product Declarations (EPDs) and UL Greenguard Certifications, which help manufacturers create—and help buyers identify—tile and flooring installation materials’ impact on the environment.