Choosing the Best Adhesives and Mortars
Most flooring installations require some type of adhesive or mortar, but with the plethora of options available from multiple manufacturers, it’s easy to see why some contractors might just throw up their hands and choose the least expensive option from whichever brand they trust the most. However, as our panel of adhesive and mortar manufacturers were quick to reveal, choosing such a crucial product based primarily on cost is the worst way to make this type of decision.
Choosing the Right Adhesive
David Fabyonic, marketing manager for Ardex/Henry, said the installer should choose a product that offers the most value, not the least cost. “As one moves up in a manufacturer’s price point scale, the professional installer should expect a corresponding increase in the value the adhesive provides to their business operation. Additional features and benefits can range from improved warranty periods to longer working times, and even the ability to install numerous types of flooring with a single adhesive.”
MAPEI’s Dan Marvin, technical services director, echoed those sentiments. “In a very rough sense, the more you pay, the more of the ‘active ingredient’ you are getting. If a contractor wants a one-size-fits-all solution, typically they should be looking at a product at the higher price point. Using a ‘good’ or even a ‘better’ product all the time simply because that’s your go-to will eventually get you in trouble.”
He added, “A basic adhesive might be fine for installing a non-exotic floor in a stable, dry, interior area. Once you start veering outside of these conditions, however, you should consider upgrading to a product designed for whatever environment the flooring will see in service. A quick reference to the Technical Data Sheet for the adhesive you’re considering will show the substrates, service environments and flooring products MAPEI considers suitable. If you don’t see your substrate, condition or flooring listed, it’s probably time to try the next rung on the ladder.”
David Ford, Stauf USA vice president of sales and marketing, noted: “In a nutshell, adhesives are primarily made up of four ingredients. Adjusting these ingredients in different ratios offers different results. One adhesive may have more green grab while another may have better shear or tensile strength. An installer should be using the correct adhesive for the correct product and avoid an ‘any old glue will do’ mentality based upon brand alone.”
He believes using a top-of-the-line adhesive also shows an installer’s professionalism. “It’s juvenile to think that a four-cents-a-foot adhesive is great for a $2.50-a-foot floor covering. Why would anyone ruin their business or reputation on an inexpensive adhesive in an installation that is based upon that very foundation? In my opinion, ‘good’ is not what I would stake my reputation or business on. At the very minimum it should be ‘better’ and that only depends on how serious you are about the two most important categories of your business—integrity and reputation.”
David Clarkson, DriTac’s vice president of national accounts, stated that premium-grade flooring adhesives help installers “consistently achieve successful installations.”
“Loyalty to trusted brands does help garner successful results and a truly credible brand would never put their name on something that was anything less than the highest quality. That said, success is measured in various terms and achieving successful results can have different meanings depending upon what the end-user is trying to accomplish.”
According to David Stowell, Schönox HPS North America technical director, while flooring contractors and installers usually opt for brands they are familiar with, ultimately “many setting materials are sold out of convenience and mostly price.”
“We recommend that contractors use the right adhesive or setting material for the right application,” he added. “Schönox HPS does not offer a good/better/best offering but rather the right adhesive for the right product application at the right time—the first time.”
Lauren Zinn, QEP’s marketing communications coordinator, broke it down this way. “Good adhesives are typically used in residential installations. These are not meant for areas where high foot traffic is expected, due to the lack of sheer strength in the formula. Loop pile carpet and felt backed vinyl will both work fine with these economical grade adhesives.
“Better adhesives are relatively versatile and can be used in commercial areas where light to moderate foot traffic is expected, such as a small office or waiting room. These are more affordable than your ‘best’ adhesives, while maintaining quality and confidence in the installation.
“Consider the best option as an insurance policy for the job. Premium adhesives are great for large commercial jobs in high-traffic areas such as airports, hotels, offices and school buildings. They typically contain more latex and solid content to prevent breakdown from wear and tear. Solid backed or PVC backed vinyls will usually take a higher-end adhesive.”
According to Sonny Callaham, Royal Adhesives & Sealants technical product manager, “Adhesive choices need to be made once the scope of the installation is fully understood. For example, is broadloom carpet going into a dentist’s office or a convention center? The contractor should also consider the longevity of the life of the flooring. If the material will be removed in two years, there is no need to use the highest-quality adhesive.
“Another factor is the time provided between installation and usage. Too many times, the end user is ready to work on the flooring right after it is installed and does not provide the required time for the adhesive to set. In this case you sometimes need to adjust the type of adhesive used. Moisture vapor emissions and the relative humidity in concrete slabs will also dictate the level of adhesive required.”
Cate Vanegas, Bona US director of marketing, said that “almost all adhesives provide a measure of moisture protection, sound-deadening properties and shear strength. So what needs to be determined is which of those attributes is specifically required for that installation.”
She added that other factors can come into play when making a decision. “I think the cost of the wood as well as the total cost of the project can be additional determining factors to consider. Developing a relationship with a manufacturer’s technical department or reps can also go a long way in assisting when there is a question of which product to choose.”
H.B. Fuller Construction Products brought together Tom Plaskota, Pat Mukushina and Mike Bobak for input. They responded that “there are so many different options for flooring and ways to install adhesives. For example, TEC RollFast [vinyl flooring adhesive] is a ‘better’ option because the contractor doesn’t have to be on his hands and knees. In addition to the price of the product, the ease of use as well as the installation time are important factors for assessing overall quality.”
Regarding choosing a good, better or best option, Franklin International’s technical flooring market manager, Mark Lamanno, said: “The only instance in the Titebond line-up where we might refer to good, better and best are the three urethane wood flooring adhesives we offer: Titebond 801 Preferred, Titebond 811 Advantage and Titebond 821 Premium. However, they differ primarily in strength so they might be better characterized as ‘strong, stronger and strongest.’
“Other than that, we developed one product for each of our other three adhesive technologies: 991 PROvantage Advanced Solvent Wood Flooring Adhesive, advanced polymer all-in-one Titebond 771-Step Wood Flooring Adhesive and Titebond 231 Acrylic Polymer Wood Flooring Adhesive. Each is absolutely the best in its category.”
Marlene Morin, Sika’s interior finishing marketing manager, commented, “Between solid and engineered woods, the performance of the adhesive can vary as the elasticity that it requires needs to be adjusted. You also have all-in-one solutions in wood floor adhesives that solve moisture issues on the concrete slab and offer sound control.”
Choosing the Right Mortar
Zinn stated, “There are variables that you should consider when choosing the most appropriate mortar, including moisture, movement and slab conditions. Choose the correct mortar based on the job and type of tile you are installing. Large format tiles require the best option, whereas smaller tiles, such as 8”by 8” can be installed using a middle-grade mortar.”
Russ Gaetano, Ardex’s senior marketing manager for tile & stone installation systems, noted that as tile and backings have changed, so have adhesive formulations. He described his company’s Self-Drying Technology as an example. “This revolutionary formulation binds the water in the matrix, allowing the mortar to be rapidly set and dry without the need for evaporation. This is ideal for moisture-sensitive tile and stone, super format/large panel tiles, uncoupling membranes, etc. Unique specialty applications of these types require specific performance attributes from a mortar. This is why more situation-specific, specialty type mortars are required.”
Gaetano added, “Some contractors always try to get the least expensive bag price possible, but don’t take into consideration things such as whether the product is easier to work with, can be trafficked and grouted sooner, and gets better coverage rates or has longer open times and pot life so there is less wasted product. Being educated about the elements of the installation, the type of tile/stone being installed and thoroughly understanding the differences between Mortar A and Mortar B can make the installer much more productive, cost-efficient and profitable.”
The H.B. Fuller panelists noted: “Mortars have different ANSI standards depending on the substrate; different substrates have different recommendations. Difficult to bond to substrates would need a ‘best’ product. Gauged porcelain panels are an example of a product that needs to have the ‘best’ mortar. Demanding environments are also factors that can affect the product decision process.”
Art Mintie, Laticrete’s senior director of technical services, shared a similar perspective. “Industry installation methods and standards require various product performance levels that will match products to the application, based on complexity. Usually the more demanding applications—such as areas exposed to heavy traffic and service—require the ‘best’ adhesive mortars, grouts and installation accessories. These types of applications require the installation products to have better working properties and ultimately better performance properties and characteristics such as higher bond strengths, flexibility and weather resistance.
“The ‘better’ category products can be used in less demanding applications—for example, interior applications with smaller format finishes. For interior, dry areas that see less traffic and potential stress, installers may use ‘good’ category products.”
Steve Taylor, Custom Building Products director of architecture and technical marketing, said mortars are always formulated for different levels of performance. “Some have increased bond strength, which is required in more demanding situations. Some have been designed for exceptional adhesion to specific tile—such as porcelain, glass or natural stone. Others have improved flexibility, longer open times or more sag resistance for walls.”
He added, “If a contractor feels the area will have little or no traffic and may be replaced in a few years, then a ‘good’ mortar may be acceptable. But if they are installing tile in a wet area, exterior or location with high traffic, they may want to use a ‘better’ or even the ‘best’ mortar available. The cost of upgrading the mortar may be insignificant compared to the cost of replacing damaged tile in just a few years.”
Carie Yaka, marketing communications manager for Parex USA and its Merkrete brand, shared some questions to ask when choosing the best setting material for the job. “What is the material to be set—ceramic, porcelain, marble, glass, natural stone, etc.? What is the size of the tile or stone—how thick and how heavy? Where are you installing this material—on the floors, walls or countertops, interior or exterior; and above, on or below grade? What type of substrate are you installing over—concrete, wood or a membrane? Are you using a light or dark grout? Are there any other requirements?”
She stressed that the cost of the mortar should not be a primary consideration. “Too often we experience the aftereffects of very expensive natural stone or tile installed with the incorrect and cheapest available thin set. It’s like trying to hit a major league fastball with a whiffle ball bat. Prepare yourself with the proper equipment and/or material to be successful.”
Yaka added, “Most ceramic and porcelain tiles 14" x 14" or smaller can be installed with a standard-grade, polymer-modified thin set mortar. Heavy natural stone and/or tiles 15" x 15" or larger tiles must be installed using a large and heavy tile mortar (LHT) or medium-bed mortar. Choose mortars with non-sag/non-slip attributes for wall installations. Use epoxy mortars for resin-backed tiles and other hard-to-bond-to tiles and substrates.”
Alan Kin, sales and technical for Texrite, said that installers need to get out of past mindsets and embrace current technologies. “Some of these tried-and-true practices can’t keep pace with newer developed waterproof membranes, uncoupling sheets, crack isolation mats or sound abatement membranes; not to mention large heavy tiles, thin-porcelain tiles and/or glass tiles that were not part of the past mentorship/training/exposure.”
He said that mortar selection should follow these guidelines: “Mortar will bond to clean, new concrete or new gypsum sheeting when a ‘good’ grade is chosen. Denser tiles or harder-to-bond surfaces such as new tile over old existing tile would need a ‘better’ grade. Applications over impervious/dense tiles and bonding over minor vibration-flex movement and/or minor hairline cracks in slabs will need the ‘best’ grade mortars.”
The ‘best’ mortars can also offer extra peace of mind, Kin noted. “Jobsite conditions are often less than ideal. This is where the higher and highest level mortars are able to enhance and augment the bond when needed. Look upon mortars selection not just as a materials cost, but as a [vital] tool for installation.”