Through my experience teaching professional installers and also my years of installing, I have found there are several common mistakes that might occur during installations. Fortunately, these mistakes are easy to avoid.
Laminate Needs to Float
Laminate flooring must float. Sometimes the installer gets comfortable and forgets this basic rule. A ¼” to 3/8” expansion, depending on the product, is required at all vertical obstructions including doorframes and at each transition strip.
Doorframes: When undercutting doorframes, the installer should confirm there is enough room for expansion. This may require cutting back the sheet rock. It is also necessary to cut the baseboard back from the casing about one inch. This will give the floor room to expand or contract in all directions.
Transition strips: Transition strips become problematic if an installer uses construction adhesive to secure the strip to the subfloor. If too much adhesive is used, it oozes on the flooring and locks the entire floor in place. If it is necessary to use an adhesive to secure the subfloor, silicone is a strong adhesive and remains flexible. I recommend using the track that is included. On wood subfloors, I recommend screwing the track down. On concrete, I recommend drilling holes with a masonry bit and fastening the track with plastic anchors and screws.
Floor Flatness may also be a problem during installations. Installing over an uneven subfloor could result in excess movement that might cause gaping and possible breakage. All subfloors require some preparation. Industry standards specify that the surface of the subfloor must be flat to within 3/16” in a 10-ft. radius. Laying a straight edge across the floor to find the high and low spots will check the flatness. All high spots need to be ground down. To fill low spots in the subfloor, I recommend using Portland-based leveling compounds approved for this application. Allow the patching compound to dry thoroughly before proceeding with the installation. Consider using a self-drying patch. Also, never use additional layers of foam underlayment to fill voids.
Another issue to be checked before installation is the moisture content of the subfloor. The moisture content of the subfloor is just as important for laminate as it is for hardwood floors. High moisture in subfloors will cause peaked seams in laminate. Laminate flooring has a core that is hygroscopic, meaning it absorbs moisture. Similar to hardwood floors, laminate floors will expand or contract as it changes moisture content. It is critical that all subfloors are tested prior to installation, and I recommend recording these measurements for future reference. New concrete must cure for at least 60 days and then be tested. Cover all concrete slabs, regardless of grade level, with a non-recycled resin 6-mil polyethylene film as a vapor retarder.
End joints on adjacent rows need to be staggered according to the manufacturer’s recommendations. Poorly staggered end joints coupled with an uneven substrate will result in planks disengaging. Boards are staggered to add structural integrity. The best way to determine the distance between end joints is to read the instructions. For many of us who have installed countless floors, instructions are often passed over. The floor you are installing today is not the same floor you were installing a few years ago. If you have not recently read the latest instructions, there is a possibility that you are making a mistake.
Laminate flooring is praised for ease of installation, but mistakes are still possible. Proper installation is an important factor in the consumers overall satisfaction with the product. Consumer satisfaction means more laminate flooring being chosen and more installations for installers. There is a payoff for you for a job well done.