Going up the Wall: Installing Flooring Vertically
Installers looking to enhance their skillset have a new opportunity when it comes to the wall. Laminate, hardwood and LVT flooring is increasingly being installed vertically to create accents (and conversation pieces). We asked several industry experts to share their perspective on what installers should know and what they should expect when taking an installation up the wall.
Installing laminate, hardwood and LVT on the wall
According to Bob Behnke, technical support manager for Franklin International, any type of flooring is fair game for use on walls. However, he added, “some local building codes may dictate weight restrictions for walls. Typical face paper shear strength for drywall is around 40 psi, but I would limit weight additions to 10 psi. I doubt anyone would exceed the 10 psi value, but people will do some surprising installations.”
Prepping the wall is similar to prepping the subfloor. “The wall should be free of any dirt, dust or loose drywall compound. Any dusty drywall compound should be primed (with a 50/50 mix of Titebond Original and water) or painted. Adhesives should be selected that will stick to the specific wall surface and the flooring material being attached,” Behnke said. “If the wall is painted and the flooring material is non-porous—such as LVT—a moisture-curing adhesive should be considered as use of a solvent or water-based adhesive may not dry when placed between non-porous materials. Another selection criterion is to be sure the adhesive is strong enough to hold the flooring materials to the wall without them slipping over time.” He added that some LVTs will require a plasticizer-resistant adhesive. “Some of these products contain a high level of plasticizer (oils) that can absorb into the adhesive and weaken the bond.”
When installing these types of materials on the wall, “full adhesive coverage is not always necessary, as hollow spots are not an issue with the wall as they are on flooring,” Behnke noted. “The adhesive should be ‘balanced’ to keep the flooring material from moving or rocking if stress is placed upon it—such as leaning against the wall.”
Additionally, depending on the weight of the material, the flooring may need to be braced until the adhesive builds up enough strength. “Adhesives with good creep resistance need to be selected unless there will be some mechanical fasteners or the flooring materials are braced or supported. Adhesives like Titebond TiteGrab can be used, which are designed to hold higher amounts of weight without bracing.”
Dan Natkin, Mannington’s vice president of laminate and hardwood, stated that nearly any engineered hardwood or laminate floor has the dimensional stability and performance characteristics necessary to be placed on the wall.
“For wood and laminate, a clean, flat and dry surface is critical. When selecting an adhesive, using a high-quality urethane with good green grab is also critical to avoid planks sliding on the wall,” he noted. “Taping the wall, like you would a floor, also helps. Additionally, the final rows that will be covered by a wall base should be nailed into place to ensure sliding will not occur.”
According to Arthur Mintie, Laticrete’s senior director of technical services, “as a general rule, any type of hardwood planking can be glued directly onto drywall. However, LVT or laminates must not be installed directly over wallpaper or existing paneling, as this will result in installation failure.”
He offered these tips: “Laminate should be adhered to the wall starting at the bottom of the wall, using silicone applied in an S-shaped pattern. Once [the laminate] is pressed down, the installer should drive a brad nail through the extended groove at each wall stud. Next, drywall screws should be placed at each wall stud at the bottom edge of the first row of planks. This area will eventually be covered by wall base. For all following rows, a brad nail should continue to be used for durability.”
Dan Marvin, MAPEI’s director of technical services, stressed the importance of always checking with the adhesive manufacturer before starting a flooring installation up the wall. “It requires strict adherence to the manufacturer’s recommendations for flash time, and possibly mechanically holding the material in place, until the adhesive has cured.”
He explained that “the challenge with moving products up the wall has to do with the adhesives—most of them are not designed for the quick grab required to hold products in place until the adhesive cures. A quick call to your adhesive supplier of choice can make all the difference between a great-looking, ‘avant-garde’ installation and a pile of vinyl and an unhappy customer.”
Greg Gelston, president of Profilitec, said to keep in mind the porosity of the wall substrate as well. “Absorption levels of the substrate can determine the type of adhesives that should be used. For thinner resilient types of surface coverings such as LVT, additional steps need to be taken to assure smoothness of the surface so that nail or screw holes don’t telegraph. All wall surfaces need to be clean and free of residue.”
Michael Provenzano, marketing manager for PPG’s adhesives and sealants division, recommends multi-purpose adhesives such as his company’s Liquid Nails Fuze*It All Surface construction adhesive. “The adhesive is formulated with a proprietary hybrid-polymer blend, with two times the strength of fasteners alone, and bonds nearly all materials in any weather conditions, and on surfaces that are dry, frozen or wet,” he stated.
Before using any adhesive, “remove all dirt, oil and debris from the wall substrate, and make sure it is dry. The contractor should also ensure that the adhesive and/or mortar selected for the project is rated to bond to both the wall substrate and the material being adhered to the wall,” Provenzano said. “If contractors are applying a material not normally recommended for wall applications, it is best to test the adhesives and materials first to ensure a suitable bond. It’s important to remember to use adhesives that are strength-rated to support the weight of the flooring material used for each project.”
Installing tile and stone on the wall
Installing hardwood, laminate and LVT flooring on walls might seem like a unique approach to working with the material, but installers are already installing flooring on walls every day—in the form of ceramic tile and stone. While almost any tile or stone meant for the floor can be attached to the wall, products that are rated for walls only should never be used on floors.
“Any type of stone, ceramic or porcelain tile designed for the floor can be installed on the wall, with the only limitations being weight,” noted Jay Samber, senior director of installation product sales for Dal-Tile Corp. “The only product that should not be put on the wall is a paver that is 2 cm thick.”
When installing ceramic and stone floor tiles on walls, “a non-sag, large and heavy tile (LHT) mortar should be used,” he said. “Spacers and properly used lippage tuning devices should also be used to keep the tiles’ grout joints consistent and in place during curing. Good surface preparation and a solid installation will keep the tile in place for the life of the structure.”
Marvin noted that wall products such as “white-body wall tile is typically too easy to break to make a good floor tile. Certain types of glass and tiles with soft glazes also aren’t great candidates for floors because the finishes wear easily with foot traffic.”
He added, “We’ve seen people putting the new 2 cm (almost 1-in. thick) porcelain panels on walls, which seems crazy from a tile perspective, where most tile is less than half this thickness. However, since many installers are used to setting slabs of granite and marble on walls, the techniques and products to install tiles of this size and weight exist.
“Tiles that are larger than 15 in. on any side and/or weigh more than 5 lbs. per sq. ft. are considered large and heavy tiles and should be installed with mortars designed for them. There are building codes that restrict the size of tiles that can be directly bonded to walls for exterior applications; typically these must be set with both an adhesive and a mechanical fastening system.”
The basics for prepping a substrate to receive tile also hold true for walls, he stated. “The flatness requirements are the same—no more than 1/8 in. difference in any 10 ft. and no more than 1/16 in. in any 2 ft. Historically, this flatness was attained with a mud-bed installation, but those have become less and less popular as construction time frames have become compressed. Today, typical framed walls will require some patching and, possibly, rendering of the entire wall to reach this requirement.”
Applying mortar to the wall will follow similar techniques used for the floor as well. “This means the usual trowels and spreading techniques can work—and getting full coverage with the mortar is important,” Marvin noted.
Where walls and floors really differ is the layout. “There is an art to walls that requires a bit more pre-planning. Typically, tile doesn’t start at the lowest point and work up—a ‘ledger-board’ is used to start with an even row and then cuts are made afterwards to fill in below it. Spacers are also critical when maintaining a grout joint is necessary.”
“Corners can certainly pose a challenge, too,” Marvin added. “A frequent issue we see with corners is the tendency to grout these with cement grouts. The industry recommends that corners, particularly inside corners, be left open and then filled with a sealant such as silicone. This will keep the tiles from cracking.”
Gelston noted that, in regards to laying out a wall tile installation, “it is important that small cuts are avoided as much as possible. The most critical part of the process is the ‘dry’ measure of the surface beforehand to assure you don’t end up having small pieces at the inside or outside corners.”
Mintie stated that wall tiles should be laid out in this method: “Find the center point of the wall and then use a level to draw a line indicating this point. Ensure that cut tiles in the corners are no less than a 1/2 in. of a tile. Using trim pieces for outside corners (if available for the tile finish) are always the better aesthetic option to trim out a project. If no manufactured trim pieces are available, on-site mitering or the creation of bullnose trim pieces might be in play.”
He added the following tip about working with gauged porcelain tile panels: “It is important for installers to pay extra attention to cleaning out any leftover adhesive mortar in the joints to ensure enough grout fills the grout joint. Additionally, an even adhesive bond coat is required to achieve proper coverage and eliminate voids under the tile while minimizing slumping of the tile. Since the installation is vertical, this will require an adhesive with outstanding non-sag properties.”
According to Mintie, coefficient of friction (COF) ratings help the tile manufacturer determine what stone, ceramic and porcelain tiles are appropriate to be installed on floors, based on the level of friction that makes these surfaces safe to walk on.
“As long as the material has a dynamic coefficient of friction (DCOF) of 0.42 or greater, the tile can typically be used on interior floors, while anything less can cause issues with walking traffic and may be only appropriate for walls or if used on floors, they must be kept dry,” Mintie noted.
“The Porcelain Enamel Institute (PEI) also issues five classes of ratings that define the surface materials’ hardness and durability. Class 1 ratings indicate that a tile cannot endure foot traffic and should only be used for walls. Class 5 indicates that the material can withstand heavy-duty foot traffic, making it ideal for commercial floor applications.”
Mintie added, “Both the COF and PEI ratings are considered by tile manufacturers when determining appropriate uses. The main takeaway, however, is that while floor tiles of any size or shape can technically be installed on the wall, tiles specifically labeled as wall tiles should never be used on floors as these installations will not hold up.”