ATLAS offer includes two self-levelling compounds – SMS 15 and SMS 30 – which are perfect for levelling of screeds, forming even and smooth surface, suitable beneath any type of flooring.
range of thickness 1-15 mm
installation of tiles just after 8 h
installation of flooring, carpet, PVC just after 12 h
range of thickness 3-30 mm
compressive strength ≥ 30 N/mm²
installation of tiles just after 8 h
also on timber, OSB floor
New screeds made of traditional cement mortars often require only slight, surficial levelling. Thickness of 1 mm, which is minimum for SMS 15 combined with excellent spreading, enables to use this mass beneath vinyl flooring, cork panels, PVC and carpets. The wider range of SMS 30 layer thickness (3 – 30 mm) is useful in renovation works, it is ideal for levelling existing substrates underneath new flooring.
Both SMS screeds are rapid-set products, but now it is possible to apply them even faster. Many contractors decide to lay PVC flooring after 24 hours, upon thin layer of SMS 15. The results of latest research indicate that our products can do more – they allow for even quicker application of flooring.
How to prepare difficult substrates before application of self-levelling compound?
In case of new buildings, when we place SMS on freshly applied substrates, there are usually no major issues. Problems with substrate preparation usually occur during renovation works. What should be done prior to application of SMS on a dusty or visibly weakened surface with low strength?
DUSTY MINERAL SUBSTRATES, HIGHLY ABSORBABLE
Substrate preparation involves application of a suitable primer, e.g. double priming with ATLAS Uni-Grunt. In the case of excessively weakened substrates, it is recommended to use ATLAS Uni-Grunt PLUS – fine-particle dispersion of polymer resins which penetrates into the screed even several dozen millimetres deep.
STRONG, CRACKED SUBSTRATES
Small scratches should be widened by e.g. hammering and filled with ATLAS Monter T-15 assembly mortar. Larger scratches should be repaired with epoxy resins. In addition, wide scratches can be cut across 1 cm deep and additionally reinforced with special steel plates.
TIMBER, OSB SUBSTRATES
SMS 30 can be applied on substrates made of timber or OSB boards. However, there are a few rules to follow: the substrate must be dry and clean, strong and stable, as well as matte and slightly rough. Any displacement or deformation of individual boards or their edges is unacceptable. If necessary, boards should be stabilized with screws or wall plugs. Old varnished or painted boards should be roughened. If surface needs to be matted, it requires thorough sanding, dust removal with a wet cloth. A quick-drying ATLAS ULTRAGRUNT primer should be applied over the substrate.
VERY SMOOTH SUBSTRATES WITH DECREASED ADHESION, NON-ABSORPTIVE
In case of renovation of old buildings, it is often necessary to pour the SMS on existing terrazzo. In such cases it is necessary to use contact coat – in this case ATLAS Ultragrunt. This product is special mixture of dispersion of high-viscosity polymer resins and quartz fillers. The advantage of Ultragrunt is quick drying – SMS can be applied 4 hours after priming.
ATLAS products development, is focused not only on quality, high strength and application parameters. Contractor`s opinion is also very important for us, especially in the current market realities. Nobody pays for technological breaks, but only for work actually performed. When creating our products, we keep in mind this important parameter – the time of product application and drying.
Original text: MARIUSZ GARECKI, KRZYSZTOF SZYSZKO, ATLAS Group