Installing Laminate Flooring: Underlayment, the Floor and More
Laminate flooring may, quite literally, seem like a snap. With technologically advanced locking systems and no need for adhesives, the product may seem like a no-brainer to install. However, even the simplest installation can go wrong if the subfloor isn’t prepped, the proper underlayment isn’t used and transitions between the laminate and other flooring types are not considered.
Subfloor prep and other considerations. According to John Lio, DriTac marketing manager, floor flatness and subfloor preparation is as crucial to laminate flooring installations as other types of flooring. “The prep work needed to install laminate flooring is extremely important but is often ignored or neglected due to the mistaken belief that proper substrate preparation isn’t required when a floor is floated.”
Lio noted that laminate flooring should only ever be glued down in special situations when recommended by the manufacturer. “Laminate flooring is typically somewhat susceptible to moisture; therefore utilizing adhesives with 100% solids, such as urethane or MS polymer technologies, is the alternative typically recommended in conjunction with manufacturer pre-approval.”
Mark Lamanno, Franklin International’s technical market manager, flooring, stated a full-spread adhesive should only be used when installing laminate flooring on stairs. “Today’s laminates lock together – if adhesive gets in the locking area, it can hamper assembly.” The use of locking systems also makes subfloor flatness important. “If the subfloor is not flat, the installer will have difficulties aligning the next board for the locking mechanism,” he said.
Lamanno added that laminate flooring is susceptible to expansion and contraction similar to a wood floor. “Because laminate flooring is generally made with HDF, they lack the grain of real wood and can expand in any direction. The locking system itself is meant to address this characteristic.”
According to Ron Loffredo, H.B. Fuller Construction Products senior area technical manager, a successful installation comes down to following the flooring manufacturer’s instructions. “Substrate variation can prevent a laminate floor system from fitting together properly, cause lippage and lead to uneven wear patterns on the floor. Consult with your manufacturer for information about flatness requirements.”
He also said acclimating the floor is important. “If, for example, an installer brings laminate flooring in from a colder space and immediately installs it, warmer temperatures could cause it to expand. This process could cause the boards to peak. Proper acclimation will minimize the likelihood of expansion and contraction.”
Jason Webb, product manager for Harris Wood and Faus, said subfloor flatness “plays a major role in the final quality of the floor install.” He also noted that installers should keep in mind that the floor will expand and contract. “While there may be less [expansion and contraction] than solid wood, remember that laminate is wood components and wood fibers. To minimize the effects, maintain the interior environment and be sure to follow proper manufacturer instructions. Over concrete, a moisture barrier such as 6 mil poly should be used.”
If a subfloor needs leveling prior to the installation of laminate flooring, Keene Building Products’ Joe Hostler, director of sales, follows this rule of thumb: “3/16-inch deviation in 10 lineal feet. If your floor falls out of this tolerance, you need to make corrections with an underlayment or you will face difficulty installing the laminate properly.”
When choosing a product to level the floor, “most products are suitable,” he said. “It’s just an issue of how fast you want to get on the floor, whether you want to trowel or self-level depending on the size of the job. I personally would use the gypsum products as they are better value for money, dry very hard, don’t mold and are easy to apply. Cementitious is also fine.”
Jeff Johnson, MAPEI’s Floor Covering Installation Systems product manager, said outside of stair treads and risers, laminate flooring should never be glued because it could damage the floor. “Laminate floors experience dimensional variation in changes with temperature and humidity, much like hardwood floors do, but they experience these changes at a different rate than the substrate beneath them. If you adhere them or stick them in place it is possible that the floor could become damaged.”
He added that proper subfloor preparation can spell the difference between a professionally completed installation and an angry callback. “Flatness is extremely important for laminate floors in order to avoid a spongy feel under foot. Virtually all laminate flooring requires some form of foam type moisture-resistant underlayment pad. This pad will accommodate some subfloor variation but they are typically less than 1/8” thick.”
Johnson noted, “Beyond flat, [the subfloor] must be smooth and free from debris. Dirt and sand granules underneath laminate flooring is like listening to fingernails on the chalkboard. It is a crunchy sound that no one wants to hear. The underlayment pad will accommodate some dirt or sand but not all.”
According to Ron Starkey, instructor for the North American Laminate Flooring Association’s (NALFA) Certification School, it is important to allow adequate expansion space for laminate flooring. “All laminate floors will expand and contract as a result of changes in the environment such as temperature or humidity. There really is no way to prevent this. Expansion and contraction are simply characteristic of this type of floor.”
He noted that both installers and inspectors can benefit from certification and training in laminate flooring installation, such as the classes offered through the NALFA Certification School. “The format is combined classroom and hands-on experience. The topics covered include a history of NALFA, Laminate 101, Installation Requirements, Inspection Tools & Standards, Product Defect Review, Inspection Reporting & Process, Certification Testing, and Evaluation.”
Upcoming NALFA installer classes include July 10 in Ringgold, Ga.; Sept. 25 in Anaheim, Calif.; and Nov. 13 in Salem, N.J. Inspector courses are offered the following day in each respective city. For more information visit nalfa.com.
Choosing an underlayment. Webb said laminate should always be installed with underlayment, provided the laminate does not already have a pre-attached cushion. “The underlayment should have the ability to reduce sound transmission. It should also have a moisture barrier if the product is being installed over concrete or other subfloors with potentially high moisture or moisture fluctuations.”
MP Global Products’ Kelly Kennedy, national sales manager, agreed that underlayment should always be used under laminate flooring. “Laminate is inherently loud, both in the room and in the room beneath.” Duane Reimer, technical director, agreed. “Laminate on a wood or concrete subfloor without any underlayment would be very noisy.”
Kennedy said an underlayment for laminate flooring should “reduce noise, and absorb and dissipate moisture both from the concrete below and from top spills.” Added Reimer, “Underlayment should be at least 1 millimeter thick and needs to have appropriate compression resistance. It should also have sound-abating properties. Depending upon where it is used, it should also carry a water vapor transmission rating that matches NALFA recommendations. If a consumer purchases an NALFA-certified underlayment, then he or she needn’t worry.”
Bob Cummings, Pak-Lite Inc.’s (PLI) sales manager, flooring products, said an underlayment for laminate flooring needs four properties. It must support the locking joint system, “which could potentially disengage with too much up and down movement.” It should provide a solid feel underfoot. “A quality underlayment with good deflective properties eliminates what we call the trampoline effect.” Over cement, the underlayment should act as a vapor barrier. “PLI has a unique process where we melt a polyethylene film coating vapor barrier onto our moisture-proof closed-cell materials. Finally, it should “enhance the reflective sound quality in the room and when necessary reduce sound transfer to lower rooms in multi-story homes, condos and apartments.”
He stated there are many laminate underlayment products on the market, including PLI’s fan-fold underlayment. “It is sold under the names Blue Hawk 4-in-1 in Lowes stores, Selitac in Menards stores, and Floor Comfort in RONA and Reno Depot stores. This product is unconventional in that it comes in a box similar in size to a laminate flooring box. The product is easy to install since it lays perfectly flat.”
Bill Devin, Sound Seal/Impacta Flooring Division national sales and technical manager, said to always go by an underlayment’s technical characteristics, not its price. “Some are very thin and offer minimal performance but are priced competitively,” he warned.
He added that a good underlayment will stop any concern about hollow-sounding floors. “Advancement in wood fiber underlayments technology under [Impacta’s] Paladin & Redupax brands has eliminated the hollow-sounding floor while providing credible acoustic performance.”
Installing the floor. Armstrong’s Tony Pastrana, installation training and system developer, offered these tips for installing laminate flooring. “Always check each board for damage before installing. Avoid narrow pieces at the finish wall. Measure the distance between the starting wall and the finish wall, then divide this number by the width of the board. If the remainder is less than 2 1/2”, cut off 2 1/2” from the width of the first row or, to balance the room, add the difference to the plank width and divide by two.”
When facing wall irregularities, installers will need to cut the first or last row of boards to fit the contour of the wall. Installing laminate through a door jamb or under a toe kick also requires special considerations, he noted. “Using a small plane or utility knife, plane or shave off 75% of the ledge of the groove. After the groove ledge has been trimmed, place the board in position laterally and lightly pull the board into place using the pull bar. The joint should be tight with no movement; a thin, 3/32” bead of glue on the top of tongue only should be used at this juncture to ensure joint integrity.”
In wet areas such as in bathrooms and by sinks, all joints will need gluing. “Apply a thin, continuous 3/32” bead of glue to the top of the tongue only. A thin, continuous bead of glue must ooze to the surface as the laminate pieces are locked together. Proper gluing provides both strength and moisture resistance to the joint. Wipe off excess glue with a damp cloth. All perimeter expansion zones must be completely filled with 100% silicone caulk following the manufacturer’s recommendations.”
According to Brad Young, Kronotex installation trainer, the biggest misconception contractors and installers have about laminate flooring is believing all products are the same. “Each manufacturer uses different locking systems and even a combination of different locking systems on the same plank. The professional with the longest resume has seen everything, but should stick check installation instructions carefully before installing.”
When installing laminate flooring in kitchens, consider any hard, heavy or sharp objects that might damage the floor. “Wet-mopping is another consideration – many homeowners want to wet-mop the kitchen, and wet-mopping is not a suitable cleaning method for any type of laminate floor.”
He added, “When installing in a kitchen, remove the kick plate in front of the dishwasher and raise the legs at least the thickness of the floor and underlayment. I place a small piece of the flooring under each leg.” Young noted in wet areas it is a good practice to apply glue to the tongue of the laminate floor only “as this limits the amount of glue and holds it up where the topical moisture will try to enter.”
Dan Natkin, Mannington’s director of laminate and wood business, said before installing the floor, let it acclimate for 48 hours. “It’s not required, but it is a best practice and it is something I would do.”
He stated that installing laminate flooring in wet areas should depend on how wet these settings actually are. “Something like a full bathroom is not somewhere where laminate is appropriate. A kitchen is perfectly appropriate, or a half-bath that doesn’t go through a lot of humidity changes. So long as there’s no standing water, and the water gets off the floor quickly, you won’t have issues.”
He cautioned against a couple of common mistakes installer and contractors can make. “If you put down too thick a pad, it can actually damage the joint on the laminate. Also, although laminate is engineered to be highly scratch-resistant, it still can scratch. Don’t drag a piece of furniture over it – take care while installing it.”
Finishing touches. Starkey said when working with transitions, the track should be fastened to the floor with screws. “If installing the tracks on a concrete substrate, drilling and inserting anchors into the concrete may be required. Laminate transitions should not be glued to or nailed through the laminate floor.
He recommended to always make enough room for proper expansion of the flooring when installing transitions. “The floor cannot be cut tight to the transition track, which would be the same as cutting the laminate floor tight to the wall.”
Ceramic Tool Co.’s April Short, director of marketing, said metal profiles for laminate flooring are an option, but the challenge is “it would create a bump under the laminate that would eventually crease or crack it. You can use a 5” or 6” putty knife to gently feather a skim-coat out about three to four inches off the metal leg.”
She added, “I think a lot of installers don’t think you can just glue or tape down a metal transition, but you absolutely can. There are some really good construction double-sided tapes to stick the leg directly to the floor.” With metal T-bars, she recommended putting a bead of glue along the underside of one lip so the trim can move freely on the opposite side. For a metal reducer, either screws or glue can work. “If you are gluing it down, you might want to fill the empty space with mortar in addition to a construction adhesive on the nose and leg. This would prevent any kind of caving in if you have a heavy traffic area.”
Sean Gerolimatos, Schluter Systems technical director, said his company offers Reno-T and Reno-TK profiles that can be used with laminate floors. “Reno-T is a T-shaped profile installed as a transition between hard surface covering, such as tile and laminate, at the same elevation. Reno-TK is a sloped profile installed in conjunction with tile to transition to a lower surface covering. While it is typically used to transition to carpet, it can be used to transition to laminate if the elevations work out. It’s probably best to install the laminate first and then the profile and tile.”
According to Thilo Hessler, Versatrim president, his company offers a range of transitions for laminate. “Our T-molding, reducers and end caps are all available with a metal U-track. We also have a new three-in-one molding called the Slim Trim which takes on the function of these three moldings and it has been a blockbuster for us.”
Bill Treiber, Moldings Online sales and account development manager, said another option for laminate transitions/moldings is those made of hardwood. “With custom blending on wood profiles of just about every thickness on most every species in a wide variety of special finishes, customers get an upscale finished look that further accentuates the laminate floor.”
Todd Hall, Cal-Flor Accessory Systems’ vice president of product development, stressed the importance of providing room for the flooring to expand. “The flooring needs to be able to expand and contract. In claims we manage from manufacturers, a huge percentage of failures is due to the lack of this one simple requirement.”
He added, “If we could offer any advice to installers, it would be this: ‘If you want your customer’s floor to be fully warranted by its manufacturer, put transitions in between rooms,’ and ‘Remember, the expansion gaps listed in the instructions vary by manufacturer and are the minimum space required.’ It’s surprising how many floors we inspect that hard-connect room to room and have little or no perimeter expansion.”
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