As part of these construction solutions, Bostik offers an extensive assortment of levelling compounds. Luc Wouters, business developer of floor technology for Belgium, is the ideal person to tell us more about this. Luc has over 34 years of experience at Bostik and he supports his contacts and colleagues by giving advice for substrate preparation and providing training courses. Luc explains: ‘Floor technology comprises all products for repairs to covering floors, damp screens, levelling compounds, and wall and floor adhesives. Bostik has products and suitable materials for all phases of a project.’

The playing rules which lead to expertise
His first piece of advice is: ‘Analyse the base and the floor. The levelling compound to be used depends on the type of floor. Whether you fit ceramics, carpet, PVC, linoleum, or parquet, each floor has specific requirements which you have to consider. Elements like drying time, required layer thickness, strength, and flexibility must be considered.’

‘With a flexible floor covering like PVC or linoleum, you need a very flat substrate for a seamless end result. You can’t flatten out any unevenness with adhesives. With parquet it’s a different matter. A higher adhesive consumption, and therefore a thicker adhesive layer, means you can remove any unevenness. Moreover, great compressive and tensile strength are absolutely vital to solid parquet since the wood constantly affects the substrate. And so, each fitting needs the right levelling compound.’
As we’ve already said, another requirement is the layer thickness. All levelling compounds have their own maximum applicable layer thickness. Luc Wouters comments: ‘In practice, not all substrates are equally flat, so it’s possible that you have to offset 4mm in one corner, whilst you have a much bigger difference in the other one. The Bostik levelling compound SL C940 XL (SL = self levelling and C stands for cement-bound) can even be applied up to a thickness of 5cm. The SL C780 FLEX is ideal for levelling a wooden substrate. It is a fibre-reinforced levelling compound with great bend strength.’

The next piece of advice for professionals is always to respect the stated dosage with water. He says: ‘The last thing you want is a powdery end result. And so, you must stick strictly to the prescribed quantity of water to be added. Bostik always gives these instructions clearly on the pack.’

Some products considered
Bostik offers a wide range of levelling compounds, which are easy to apply. This SL C510 PRO is suitable for use on indoor floors. SL C510 PRO is certified in accordance with EC 1+ and is thereby suitable for use in BREEAM and LEED projects.
SL C750 POLYRAG from Bostik is a fast-drying, flexible, and fibre-reinforced levelling compound specifically for levelling less stable substrates, such as wood, for instance. This product is ideal for a further finish with a floor coating.

Bostik’s fastest drying levelling compound (also suitable for use in great layer thicknesses) is the SL C990 SPRINTER. Originally, fast-drying levelling compounds were designed for use in shops and public areas where speedy and smooth renovations were needed. Closure time must be kept to a minimum. By opting for fast-drying levelling compounds, you can fit a new carpet or tile floor within two to four hours.

Developments and the environment
Finally, we discuss innovations in the field of levelling compounds. He says: ‘Generally on the market, but also particularly at Bostik, the players are making every effort to provide ecological solutions. For instance, all our levelling compounds possess at least emission certificate EC1 or even EC1+. And so, they’re absolutely ideal for use with green projects (BREEAM and LEED).’