1. What needs special attention in the installation of LVT?

The deciding factor for the attractive appearance of the flooring expected by the end consumer is perfect preparation of the substrate. The levelling compound should ideally be stretched out and de-aerated for this. When replacing cushioned vinyl or textile floor coverings with luxury floor coverings, the impact sound absorption can be significantly reduced. This problem mainly occurs in rental properties. In this instance, the luxury floor covering’s basic range of use is cleared for the respective property.

• Acclimatising the floor coverings is very important, especially for dry adhesives and roll tackifiers. These adhesives cannot prevent changes in dimension due to adjusting the temperature of the floor covering during installation (image 1).
• If something is intended to be installed on underfloor heating, then this should only be on hot-water underfloor heating and with a limit on the surface temperature of up to 28 °C maximum (image 2).
• When using in medical areas, it should be noted that luxury floor coverings must be inconveniently disinfected due to their high proportion of joints, and joint formation can be strengthened using disinfectant (this extracts plasticiser from the floor covering), which can then strengthen the detrimental effect even further.
• Make sure that castor chairs have suitable castors; furniture gliders are recommended to use under chairs and tables.

2. Have you experienced any critical installation matters with designer floor coverings? What was the cause?

Installing on installation underlays: Wet bonding is generally not possible on installation underlays due to insufficient absorbency. If the pressure bonding method is then used as an alternative by selecting a suitable adhesive, the combined effect of two “soft” layers creates a considerable risk for impressions. Similar applies for resistance to castors. If the installation underlay itself still contains plasticisers, the damage can no longer be prevented (image 3).

Complaints are inevitable when installing diagonally on roll tackifier. The many intersectional planes lead to a high number of small flooring pieces that cannot be securely locked by the roll tackifier. If movement joints are running in the space, the situation will be further exacerbated by the once again increased proportion of waste.

3. Which type of adhesive do you personally prefer?

“Prefer” would be the wrong word. What’s key in your selection is which application you’re planning on. 

First choice: Wet adhesive
Wet adhesives are good for universal use under luxury floor coverings and secure in application and surface use - the installer thus safely avoids mistakes and claims later on. But wet adhesives aren’t synonymous with “conventionally levelled adhesive,” because that also includes pressure-sensitive adhesives. However, pressure-sensitive bonding comes with a significant risk of residual indentations and dimensional changes - therefore it is no longer considered to be state of the art under luxury floor coverings today. In addition, pure wet adhesives in the system with the appropriate levelling compound tightens very quickly. It can reach more than 50% of its final strength within the first hour, which fosters high security and an optimum installation result with the respective luxury floor covering.  

Special requirements: Dry adhesive
Selection criteria include fast processing and immediate load-bearing ability, installation on old flooring, installation without impacting the job site negatively, and can be removed without leaving residue.

Limited performance requirement and flooring selection: Roll tackifier
Roll tackifier for “simple” requirements and only for dimensionally stable floor coverings. There is a restriction, however, that takes effect once the floor covering has been removed. Removing the old tackifier is extremely difficult due to their softness and lasting adhesive properties - in our experience, a new construction can follow once the tackifier residue has been “isolated” with a 2-component PUR levelling compound. 

In cases of application wherein dry or wet adhesives can be used equivalently, we would give the  preference to dry adhesive: It’s innovative, sophisticated in installation, and unmatched for environmentally compatibility.

Which type of adhesive for which installation case?
Wet adhesive is universal because 

• it works with all application conditions
• it works with all usage conditions
• it works for all types of luxury floor covering
• ensures a permanently attractive view of the floor without joints 

It is the only adhesive that can be used safely with underfloor heating, high temperatures/direct exposure to light, and all floor coverings, and can work against joint formation.
The only drawback: You have to pay attention to product-specific setting times. Dry adhesive and roll tackifier are special products for the applications described above.

4. What are typical mistakes in installing luxury floor coverings

• Failing to acclimatise the floor coverings before installation is one of the most common mistakes, in our experience. A possible consequence is that the edges of sheets bounce (image 1). The specifications from floor covering and adhesive manufacturers should be followed as a matter of principle. Unpacking the elements can be to your advantage, because these can be adapted to the environment conditions faster.
• Installing in adverse indoor climate. A possible consequence is bubbling due to defective drying of the adhesive.
• Uncoordinated systems, such as in the case of an insufficiently absorbent levelling compound, that lead to delayed hardening (image 4) or longer open time for roll tackifier when combined with wed adhesive.
• A levelling compound coat that is too thin (thickness < 2 mm) or levelling compound that hasn’t dried enough likewise lead to the described effects.
• Undersized dirt traps. These can lead to visual nuisances due to scratches.