De Realtà Mapei n.° 32 - 2/4/2021
Luxury vinyl tile (LVT) and luxury vinyl plank (LVP) flooring have changed the flooring world in many positive ways. To start, the simple portability of the flooring makes it easy to transport from the factory to the jobsite. Next is the fairly straightforward installation method that only requires a utility knife to cut individual planks to length. Finally, the attachment methods are also straightforward: Either click pieces together in a floating floor system or use a simple pressure-sensitive adhesive bonding process for a finished look.
The other aspect of LVT/LVP that we need to consider is that due to state-of-the-art printing, visual creations are becoming more advanced daily. I can’t tell you how many times I have looked at a floor and actually had to get down on my knees and touch it to see if it was wood, tile or LVT/LVP. The visuals are simply stunning, and the marketing effort behind these flooring products is making it something people actually ask for as an upgrade.
Lastly, most if not all LVT/LVP products are made from some form of plastic, making them virtually waterproof. Whether it is PVC, polyolefin, solid rigid core (SRC) or wood-plastic composites (WPC), “waterproof” or “water-resistant” is the name of the game. No wonder people are trying to figure out ways to use this attractive material in areas of their homes other than just on the floor. I have had numerous requests for installation suggestions for LVT/LVP on walls and even ceilings.
But with all the benefits of LVT/LVP, why stop with walls and ceilings? How about wet environments such as shower enclosures and tub surrounds? Crazy, you say? Thanks to new installation materials, this can be a reality.
Benefits of using LVT/LVP in wet environments
Products used to install LVT/LVP in wet environments are all provided to you premixed and ready to go. There is no mixing of powder into water. This means there is no pot life to worry about. There is also no mess from dust when it comes to installing LVT/ LVP in wet environments (or any environment for that matter).
Another benefit of this type of installation comes when you are doing retrofit installations. Traditionally, putting new tile over existing tile adds significant weight and thickness over the existing material. Depending on the tile and installation method, this can add as much as 3/8" to 1/2" (10 to 12 mm) of additional thickness to the walls. Using LVT/LVP, the maximum thickness build is typically less than 1/8" (3 mm).
Another great advantage of LVT/LVP in any application or environment is the ability to combine multiple visuals and have them all at the same thickness. Think about it. If you want to combine wood and stone, you are going to have to make sure that they all come out at the same level when you install them. For example, combining 3/4" (19 mm) solid prefinished wood flooring with a 1/2" (12 mm) thick piece of marble means that the marble must be lifted up 1/4" (6 mm) to be level with the wood. With LVT/LVP, that wood visual matches up perfectly with the stone visual without having to deal with thickness variations, because they all start at 2 mm or 5 mm in thickness.
Finally, let’s look at what LVT/LVP is made of and why it is perfectly suitable for wet environments. In general, most LVT/LVP is PVC- based. There are also many non-PVC types of LVT/LVP available, but the general conclusion is that they are made of plastic-based materials and, as such, are extremely water-resistant. In comparing the composition of LVT/LVP to other flooring choices, such as wood and tile, the differences are obvious. Wood, for example, is definitely not waterproof and is extremely sensitive to moisture in any form. Putting wood materials in a wet environment would hardly be considered prudent. Tile and stone are more common materials that would be used in wet environments, but stone types that can absorb moisture and stains are suitable for this application.
Installation steps for LVT/LVP
The installation of LVT/LVP in wet environments starts off similarly to tile projects, with the proper placement of a waterproofing membrane over the entire surface. The surface can virtually be anything ranging from cement boards to waterproof boards to drywall.
The critical success factor is 100% compliance in the installation of the waterproofing membrane. This is no different than what you would expect for tile installations, so it is crucial to make sure to follow this step according to all written instructions on Technical Data Sheets and installation guides. There are several types of waterproofing membranes available from multipart cement-based to fabric membranes to roll-on coatings, and all will work for LVT/ LVP installations. MAPEI recommends the use of Mapelastic AquaDefense for this application primarily because it is easy to apply, dries quickly and works exceedingly well.
The next step is one that is specific for resilient material being installed: Make sure the surface is very smooth and flat. If tile were being installed, you could deal with substrate defects with the mortar bed being used. But for resilient flooring materials, you must make sure the surface is smooth and flat, otherwise those defects will telegraph through to the final finish. For this, you will need a special smoothing compound that will bond tenaciously to nonporous substrates, dry quickly and be waterproof when dry. This is exactly what Planiprep 4 LVT is: A one-component, premixed skimcoating compound that applies very easily, dries quickly, sands to a super smooth surface and is waterproof when dry.
Next comes the installation of the LVT/LVP on the vertical surface. For this, you will need a special waterproof adhesive to apply a nonporous material (LVT/LVP) over a nonporous substrate. Ultrabond ECO MS 4 LVT Wall fits all those requirements. As a modified-silane-based, 100%-solids adhesive designed to install LVT/LVP of all sizes in vertical applications, it has the proper thixotropy to hold these materials on the wall without slippage. Ultrabond ECO MS 4 LVT Wall cures fairly quickly and is ready for the next installation steps in about 6 to 12 hours after installation.
Depending on the desired finished look, you may choose to use tile spacers when placing the LVT/LVP to leave an area for grouting, or you can simply butt the pieces of LVT/LVP tightly together. Grouting is not a requirement for this system and is purely an option based on personal preference. If grout lines are desired, then the only requirement is to use a resin-based grout such as MAPEI Flexcolor CQ or Kerapoxy CQ. The use of cement- based grouts is not recommended. For easiest installation, MAPEI Flexcolor CQ wins the day in that it is premixed and ready to use, although it will require about 12 to 24 hours of curing time before the final step in the process. This wait time can be shortened with the use of Kerapoxy CQ epoxy grout, which can reduce the cure time to 4 to 6 hours, but epoxy grouts are not for the faint of heart to use.
The final step – and perhaps the most important one – is the application of a sealer and non-slip coating onto the LVT/LVP. This step is accomplished with MAPEI’s Mapecoat 4 LVT, a two-part, aliphatic, non-yellowing isocyanate-based coating that seals all the joints as well as adds much needed traction for floors. Most LVT/ LVP is not designed to be used per se in wet environments and that is why the non-slip coating is so important to this process. Mapecoat 4 LVT is simply mixed together and applied using a 1/4" (6 mm) nap roller to all surfaces.
Once Mapecoat 4 LVT is applied and allowed to cure for 24 hours, the installation is almost ready for water exposure. For complete waterproofing protection, finishing details can be handled by using Mapesil T in all the corners and plane changes.
In summary, MAPEI offers an innovative system of products to enable the secure installation of LVT/LVP in virtually all environments, especially in those that will be exposed to water such as tub surrounds and shower enclosures.
About the author:
Jeffrey B. Johnson
Jeff is the Business Manager for MAPEI’s Floor Covering Installation Systems line. Jeff brings to the industry more than 25 years’ experience in the development and marketing of floor-covering installation products. Practical experience in the construction industry and as a bench chemist gives Jeff an insightful perspective on surface preparation, moisture mitigation and floor-covering installation.