Main image: FINfloor
With an increasing number of ways to install luxury vinyl tile (LVT) – glue, click and grip-strip – it has never been more important to correctly match method and application.
FLOORS magazine reached out to industry leaders to compile the following simple guide on how to best leverage LVT installations. Doing so, they said, creates additional profit opportunities while reducing work and potential headaches. As our valued reader, you have exclusive access to the specialist advice from some of the industry’s top suppliers.
Understanding luxury vinyl tiles and stone plastic composite planks
Luxury Vinyl Tiles, or LVT as we know it is not a new product and has in fact been around for over 25 years. It is a genuine alternative to both laminates, solid wood and more recently, ceramics and polished concrete, and is available in a nearly unlimited range of designs and finishes.
LVT, luxury vinyl tile is a glue-down or click product that is made up of a core of PVC topped with a décor paper, a wear layer and normally a UV protective layer. These layers form the product and determine its quality and stability.
Wanabiwood’s National Sales Manager, Grant Miles Neve, notes, “Stone Plastic Composite (SPC) is a more recent addition to our shores and has taken over from the old, less stable click vinyl’s. SPC is available in varying thicknesses from 4mm up to 8mm. Made from calcium carbonate and PVC, the core board is not only extremely stable, but also allows for slight undulations to be absorbed from the subfloor. Although a self-levelling screed is recommended to give the perfect trouble-free floor, as with LVT, the core is topped off with a décor paper, a wear layer and UV coating.”
Success starts with floor prep
Without a clean, level and dry subfloor, it doesn’t matter what LVT installation option is employed, the floor is likely to fail, says experts.
To speed up and reduce the expense of subfloor preparation, a number of suppliers now offer specific LVT-oriented moisture barriers.
“You can’t glue LVT directly onto asbestos or existing flooring like ceramic tile. You either have to remove what’s there or patch it up,” notes Grant. Additional floor prep will be required if an application needs to be done over stone/slate/wood/ceramic/porcelain with the use of self-levelling compounds.
The importance of using the right adhesive
There are two types of adhesives available, a semi flash and a wet set. Either is suitable and it is down to personal preference.
The importance in selecting the correct glue down adhesive is vital in terms of the adhesive offering dimensional stability, being fibre reinforced in selecting the correct glue down adhesive being specified.
The glue is applied as per the adhesive manufacturer’s recommendations and usually a 1.5mm v-notch trowel is used. If wet set, then lay in of the planks should be immediate, whereas with semi flash, up to 20 mins should be allowed for flash off before laying the planks.
Next comes the roller, probably the most important tool, a 68kg 3-part roller to be precise. This should be used as soon as you have enough planks laid and we recommend that you continue to roller during the installation and over the whole installation at the end of the job. Special attention should be given to getting to the very edges of the installation. It is recommended that the installation not be subjected to heavy traffic for 72 hours.
SPC is often seen as a simple product to install, but it can also give problems if the rules are not followed. As per previous instructions, it is imperative that the soundness and moisture levels of the subfloor are at an acceptable level. The floor must have only minor undulations – the recommendation is no more than 3mm in a 3m radius – but if the job is to be done to the highest level, we still recommend a self-levelling screed be applied.
Before you install, note that the industry as a whole, accepted that SPC is actually only water resistant, not waterproof, and constant moisture from below could cause possible failure of the product. Better be safe and fit a plastic moisture membrane as in most cases, this plastic will prevent possible issues relating to moisture from below. Do not use a separate combi lay or acoustic underlay, unless approved by the flooring supplier.
Once this step has been done, you are good to go. Click installation goes a lot quicker, but the attention to detail around the doorways is paramount. SPC is a floating floor and therefore, like laminates, it needs an expansion gap around the entire perimeter. However, the lengths that can now be fitted without adding addition doorway expansions is much greater than laminates – up to 20m in length and 15m on the width is the average. It is recommended to leave expansion gaps, fill it with backing cord and cover over with a neat bead of silicone on top of the floor. Once a click floor is finished, it can be walked on immediately.
Two different luxury vinyl tile installation methods
“Currently there are two main installation methods commonly used for the installation of luxury vinyl tiles, with each offering its own benefits. It is advised to speak to your flooring specialist to find out what will work best for each project,” recommends Chris Holden, Director at FINfloor SA.
- Glue-down installation
The method selected is often determined by the thickness and stability of the vinyl material that is being installed. Sheet vinyl is typically installed using the glue-down method, with heat-welded joints to prevent the spread of germs. This method is often used in hospitals or health care facilities, because of its added protection.
The development of new print technologies and surface finishes has brought about the possibility of installing individual panels of varying thicknesses (between 2 to 3mm) directly onto the screed and glued down. However, the floor preparation is critical to achieving a good installation as the screed must be level and smooth to prevent telegraphing to the surface. The services of a specialist installer are required.
The benefit of this method is larger floor areas can be covered, and if installed properly, is 100% waterproof from topical water. It also offers a seamless finish without incorporating an expansion joint or seamless joints, except where bevel joints are a feature. However, the preparation and installation work are vital and can be costly.
- Floating installation
Rigid core technology has resulted in a far cleaner, quicker and less costly method of installation for vinyl, and because of the thickness of the core, these floors are normally installed as a floating floor, i.e., not attached to the screed. The thicker core material used in the production of these panels is far more forgiving in respect of the screed/substrate it is installed on top of.
This method is very popular with DIY enthusiasts as it is hassle free, no need to invest in expensive installation tools and is relatively easy to install, provided the instructions are followed precisely.
The material’s construction means that floor panels can be installed on a relatively uneven floor, with an allowable tolerance of 3mm in 950mm.
Unlike glue-down installations, the floor area coverage is reduced and requires an expansion gap around all vertical surfaces.
Common Luxury vinyl tile glue-down failures and how to avoid them
As with any flooring installation, failures can and do occur for a variety of reasons. However, the main reasons for LVT glue-down failures are:
• Lack of acclimatisation: The LVT flooring should be allowed to acclimatise to the temperature of the installation area for a minimum of 24 hours (48 hours is preferred) to ensure stability of the flooring. For example, flooring that is transported in a hot vehicle and installed immediately in a cooler room, or vice versa, could compromise the installation, since LVTs can be sensitive to temperature and humidity fluctuations.
• Lumpy rippled flooring: This is usually down to bad subfloor prep and a poorly screeded floor. Visible trowel marks are the result of using a trowel that has too big a notch.
• Yellowing and discolouration: This is caused by a reaction between the adhesive and the vinyl, known as plastersizer migration, which normally happens if contact is used on a still wet surface. This failure often occurs on a staircase.
• Gapping on the long joints: Although not a common occurrence, if gaps are seen on the long joints, it would normally mean that the fitter has allowed the floor to run out when fitting. It only takes a small piece of dirt to sit in one joint and the floor can start to run out.
• Gapping on end joint is seldom seen but can be an issue the same as peaking. If the board contracts in the cold it can gap, however, gaps are only seen as a problem if they are larger than the thickness of a business card.
TAL’s Technical Advice Supervisor, Sharon Margon, agrees that correct substrate preparation is vital to a successful installation of any type of flooring, but adds that she feels LVT installation failures can be avoided by taking note of the following 5 key considerations.
5 considerations to avoid vinyl flooring failures
- Installation of vinyl floor coverings should not proceed before the moisture levels in the substrate has been tested and deemed suitable. If the moisture levels are not 3% (50%RH) or less, then a high-quality vapour barrier system should be applied to the surface to prevent the passage of moisture or water vapour through the substrate.
- The substrate should be integrally sound with no crumbling or cracking and should also be free from surface contamination, clean and dry. Contamination on the surface may have an adverse effect on both the finish and long-term performance of the floor covering.
- A smooth and level surface is required when installing LVTs or other PVC-backed vinyl tiles as any imperfections in the substrate will certainly affect the aesthetic appearance, and possibly the longevity of the finished floor covering.
- A good quality self-levelling underlayment is recommended before application of a suitable adhesive, which has been specifically designed for use with this type of floor covering. When installing LVTs, an adhesive with a rigid glue-line (once set) is recommended to minimise “gapping” down the line. Highly porous surfaces may require the application of a priming agent prior to application of the specified LVT adhesive to ensure a strong bond.
- Installers should carefully read the manufacturer’s instructions (both for the fixative and LVT flooring) prior to applying the materials to ensure they are fully aware of the installation requirements for the specific products.
Stone plastic composite failures
Although a simple product to install, some SPC installation problems or failures are still seen. This was the view of all three of the experts, with the most common SPC failures being:
o Peaking of end joints – as acclimatisation is required to stabilise the board in the installation area, failure to do so can cause the planks to expand while fitting them to the floor.
o Heavy furniture is an all-too-common problem as the weight causes the pin cases on the long joint to peak up.
o Direct sunlight in a particular spot means that the floor will want to expand and contract, which causes the end joints to lift, and in severe cases, can also cause extreme expansion where the sun hits.
o Lack of expansion gaps, trims that are siliconed in with no expansion left, pinning from quarter rounds and skirtings and coloured acrylic used in the doorway expansion gaps.
o Failure of the lock joint is seldom seen with quality lock joints, but can occur if the subfloor is not within spec, causing the boards to move up and down on the joints. The same as when metal is constantly bent in two directions, the lock joint simply gives in. Constant pressure from heavy items can also cause the joints to fail.
o Scratching of the floor. Most quality LVT and SPC products are scratch resistant, not scratch proof. Unless there are walk-off mats and felt pads on the furniture in the room, sadly even the best flooring will eventually succumb to scratches. In short, walk-off mats in all outside doorways and protective pads under all items of furniture are recommended.
Which is the better installation option?
Massive retail and commercial spaces such as shopping malls, hospital corridors and airports always favour a glue-down product as the stability of this option is paramount in areas with heavy foot and equipment traffic such as trolleys. The point load on a click joint leaves room for failure. Being stuck to the subfloor means that this product is also a good sound absorber.
However, here one has to factor in the cost. The need for a moisture barrier, a slurry coat, screed and adhesive, all of which will cost as much if not more than the actual flooring, needs to be weighed against the drying and installation time needed.
SPC is the perfect domestic product. If no screed is needed, it will often be a more cost-effective option than glue down LVTs. It offers instant flooring maintenance as damaged sections can simply be lifted and replaced, causing no damage to the screed below.
The disadvantage could be a noisier floor. Even with the IXPE underlays, there is still a noise factor to consider and the expansion joints are seldom as seamless as the glue-down options.
No matter the product or installation method selected, innovation and development in the luxury vinyl tile and stone plastic composite markets are vast. More and more usages and advantages when using these products are being seen each year, resulting not only in an increase in popularity, but also a more advanced product.
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