End joint gapping/buckling of luxury vinyl tile and planks has been a concern for several years and has cost the industry more headaches, time and money than we ever thought it would. Yes, it’s a category of flooring that has taken off in terms of demand, but it has its issues. Are these problems manufacturing-related, installation-related or site-related? My personal thoughts are: all of the above.
There are manufacturers that have added fiberglass or composite cores that seem to help with the dimensional stability of their products. Still, many don’t because they are trying to maintain price points.
Let’s first look at the gapping concerns. What do luxury vinyl planks consist of? That’s right—vinyl. If you’re an installer who has ever installed vinyl transitions and vinyl base, have you gone back to see gaps or shrinkage at the joints? Now translate that to LVT/LVP, because it’s doing the same thing. What do installers do to try to minimize the shrinkage? We try to compensate by over-compressing at the joints. Trying to compress LVT/LVP is not going to work because we install multiple rows and not just a single row like with transitions and wall base. So you see, we’ve been dealing with vinyl shrinkage for years.
Floating “click” LVT/LVP allows for more expansion/contraction due to no restriction of movement, which means there is more potential for end joint gaps (Photo 1). Our company protocol for floating click LVT/LVP is to do a glue-direct in order to minimize any potential shrinkage or buckling/bubbles. Does it cost more and take more time? Yes, but not having a claim is worth it for our business.
So what do installers need to do to minimize gaps? First, follow the manufacturer’s recommended installation guidelines. For a glue-direct, if the manufacturer specifies a certain adhesive, use it. If they require moisture testing over a concrete substrate, do it—and make sure to document the readings. If the product requires a certain notched trowel, make sure to use it to maintain the proper thickness of adhesive (Photo 2).
To maintain the proper spread rate, you may need to have more than one trowel on the job. Trowels will wear down, especially over a concrete substrate. If installing over a gypsum-based pour or lightweight concrete, make sure the manufacturer recognizes installations over these substrates and has recommendations for these types of installations.
Ambient conditions play a critical role in the performance of LVT/LVP also. Installing in an environment that is not controlled could come back to haunt the retailer and installer—not to mention the dissatisfied end user. The HVAC system must be operational and controlled prior to, during and post installation with minimum/maximum temperature and humidity. This can be a challenge in new construction of residential multi-family housing, and commercial. Photo 3 shows the result of a job lacking controlled site conditions: shrinkage. If site conditions are not what they should be, the retailer/installer needs to address the concerns prior to installation.
Let’s take a look at floating floors and see what some of the concerns are. Moisture, restricting the movement by not allowing expansion/contraction allowance at vertical abutments, and placing fasteners through the flooring are common factors. What about buckling/bubbles in random areas? Do the buckles/bubbles appear and disappear? If it’s in isolated areas, it may be due to sunlight. In many cases, direct sunlight has been a factor; in fact, several manufacturers have changed their warranties and state they will not warranty their LVT/LVP products in direct sunlight should buckling/bubbles occur.
If the installer doesn’t follow manufacturer guidelines, how can one blame the manufacturer? By following the manufacturer’s installation guidelines, if there is a concern the installer has done all he or she can do. Now responsibility starts to fall on either manufacturing or site conditions. So always remember to “CYA!”