Mortars have evolved greatly over recent years, in order to keep pace with harder-to-bond porcelain tiles, larger-format tiles, as well as to support slim tiles,
As Arthur Mintie, Senior Technical Advisor for LATICRETE, noted, saving time and money on the jobsite have become increasingly important as the industry pushes to offer more advanced products to meet construction needs for fast-track projects while incorporating lightweight and dust-free features. “New mortars being developed are creating ways to shorten the entire lead time of residential and commercial tile installations,” he said.
“Other mortar product developments focus on designing new products that meet or exceed regulatory requirements,” he continued, “and are equipped with supporting Health Product Declarations (HPDs), Environmental Product Declarations (EPDs) and UL GREENGUARD® Certifications.”
One of the most significant advancements for large-format tile and stone is the development of large-and-heavy-tile (LHT) mortars (formerly known as medium-bed mortars). “When tile mortars cure, they are inclined to shrink because the displacement of water causes the mortar to retract and either pull away from the tile causing uneven coverage and hollow spots or physically pull the tile down while it hardens, causing lippage,” said Tom Carroll, Senior Product Manager for Merkrete. “Newly formulated LHT mortars are designed to control the amount of shrinking that occurs during the curing process, allowing the tile to stay in position.
“These LHT mortars are formulated with non-slump to withstand movement of larger and heavier weighted tile during installation,” he added. “They also contain increased grab and non-sag/slip for vertical installations. The continued education and awareness of LHT mortars are assisting installers to make these a more common part of the installation.”
The evolution of grout
As the foundation or framing of your tile product, grout utilizes the element of design with color, style, shine and pizzazz, depending, of course, on what grout you choose to work with.
Grout continues to feature an extensive color palette, but much about its delivery and selection of color has become different over the years, from ready-to-use products that can be resealed and stored for future use, to stainproof grout, to newer dispersible-pigment products that can reduce inventory space needed in the warehouse, to grouts that incorporate metallic pigments or glass beads to enhance glass or decorative tiles. Color choices continue to grow, some coordinating with other finishing or paint suppliers or grouped into families to make color selection easier.
Advances in grout technology continue to emerge and understanding the performance characteristics and limitations of each type of grout is important, noted Merkrete’s Carroll. “Most grouts are produced to meet the requirements of a particular ANSI standard, but there are additional requirements demanded by installers or end-users. Contractors typically want grout products that have enough working time, spreads easily, completely fills joints, dry quickly, and are easy to clean. They do not want call-backs to clean grout haze and seal joints.”
Pre-mixed grout has helped drive the construction industry forward by helping installers do their jobs more effectively, noted Mintie. “In addition to time savings thanks to a faster preparation, pre-mixed grout helps to simplify the installation process by eliminating the guesswork. Installers no longer need to worry about meeting the exact amount of water necessary to achieve the desired consistency, like they would with traditional grout.”
Pre-mixed grout can also be less expensive when used for smaller jobs because these products can usually be purchased in small quantities. “Any left over grout can be saved and then used on other projects,” Mintie said, ”significantly reducing waste. Some pre-mixed grouts already contain materials like latex or urethane, which can help improve adhesion and eliminates the need for sealing.”
In the Portland cement grout category, more and more installers are electing to upgrade their grout selection to a rapid setting, CAC-Calcium Aluminate Cement, which offers higher performance specifications and typically adheres to ANSI A 118.7, noted David Mowery, MAPEI’s Business Manager for Color Products and UltraCare.
“Traditional Portland cement grouts typically only achieve ANSI A 118.6 specification,” Mowery said. “Given the trend to larger-format tile and gap widths typically in the 3/8” range, less grout is being required per square foot,” he added. “This allows the contractor/installer to justify the higher price given the higher-performance characteristics. With the higher-performance grouts, the contractor/installer will gain more performance features such as no efflorescence, enhanced color consistency, rapid setting for earlier foot traffic, and no sealing required.”
Another category of grout is showing major growth as well, noted Mowery. “The use of ready-to-use (RTU) grouts is moving out of the DIY arena and into the commercial contractor/installer channel. This is being driven by improvement in overall performance in this grout category. RTU grout chemistry includes acrylics, urethanes, and hybrid versions.
“When cost is a consideration – and it always is – the product cost for RTU grouts vs. traditional cement grouts are higher,” he continued. “Yet, when you factor in the reduction in labor time for installation, ‘no sealing’ required, no callbacks, no efflorescence, color consistency and the chemical- and stain-resistance provided by an epoxy, RTU grouts are a bargain.”
Merkrete’s Carroll agreed, adding, “Since the trend to larger format tile and smaller joint widths is growing, less grout is required for each installation. This allows the contractor to justify using a higher-priced, higher-performing grout because the square foot cost is negligible.”
Mortar Products
1 ARDEX Americas
2 Bostik
3 Custom Building Products
custombuildingproducts.com
4 LATICRETE
5 MAPEI
6 Merkrete Systems
7 TEC Specialty Products
CONTRACTOR PERSPECTIVE
Ashley Andrews
MacTown Tile Company
Macon, Ga.
As a tile contractor, I am always looking for the best setting materials for the task at hand. For me, mortar is the most important of those materials. In search of the best products I try as many as I can, and there are a lot to choose from.
Like most tile contractors I have my workhorse mortar that I use for many applications but there are situations that arise that a specific mortar is the best choice. When dealing with glass tile I prefer a mortar formulated for glass that I know will cure properly. If I have a large-and-heavy tile on a vertical surface I prefer a mortar with thixotropic properties to help hold the weight of the tile. If I’m working outdoors in an unpredictable environment, I go for a mortar that is rapid setting and can withstand a driving rain after a short amount of time, and that has excellent workability in varying temperatures. There are mortars specifically designed to handle any installation scenario.
Today’s mortars are so predictable in their performance that manufacturers are giving great warranties on them. The only thing an installer has to do is to use the right mortar for the job and to mix it according to the instructions. Often times when I hear contractors complaining about products not working as advertised I ask them if they followed the instructions and the answer I usually get is that they “eyeballed it.” Put the guesswork away, get out the measuring bucket and set the timer and the product will perform as expected.
As for the future of thin-set mortars, I hope to see more silica-free products readily available on the market. For too long we have been lax about the effects of silica in our industry and many contractors have paid for it with their health. It’s time we as an industry get with the program and start working smarter.
Grout Products
1 Bostik
2 Custom Building Products
3 LATICRETE
4 MAPEI
5 Merkrete Systems
6 TEC Specialty Products
Louis Iannaco
Louis Iannaco is a contributing editor to TileLetter magazine.