Special
Subfloors for LVT, vinyl, and PVC floors
A BASE FOR VINYL HAS TO BE SMOOTH AND TOUGH DIFFERENT RULES FOR FLEXIBLE FLOORS THAN FOR HARD FLOORS
Photo – STEICO
All sorts of floors require a specific approach and specific products or tools before, during, and after the fitting. We see one of the big differences between parquet, laminate, and flexible flooring, for instance, in the requirements for the base. The tolerances for hard flooring as regards flatness, for instance, are of a completely different order to those for flexible flooring, which is thin and more or less resilient so that any unevenness in the base stays visible in the finished floor. This means, amongst other things, that levelling will very often be necessary for flexible flooring.
The reference framework: TV 241 (B) TV no. 241 is a guideline for fitting elastic flooring. This BBRI document is a partial revision of TV no. 165 on flexible flooring, which was issued in 1986. This voluminous document is subdivided into eight chapters which familiarise professionals with the world of elastic flooring. For instance, chapter three includes a summary of the various types of floors. This chapter is illustrated with various photographs to make everything more attractive and easier to follow. It also includes a number of charts which, amongst other things, help with the choice of flooring for the required use. Chapter five is devoted entirely to the base, an essential element in fitting elastic flooring. The requirements for this base are covered at length so that nothing can be overlooked e.g. flatness, mechanical strength, permissible moisture content, etc. The recording of the latter parameter is also the subject of two appendices.
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Floor Forum International 110
Points for attention with subfloors For all floors you have to consider certain specifications before you can choose the most suitable subfloor. Obviously, that is no different with flexible flooring. We consider the floor structure with an occasional focus on features which are more or less typical of these types of floors. Generally speaking, we can say that for full glueing the screed has to be perfect or, if there are other requirements such as sound reduction, for instance, a flat/hard subfloor will be necessary.
Moisture protection For fitting floating floors, the best solution to counter the risk of damp is to fit a foil. Some flexible floors are more or less up to 100% (PVC) waterproof. Nevertheless, producers also recommend fitting a damp screen in those cases because rising damp can lead to mould. The available foils are usually synthetic. Highly common synthetics for damp screens are polyethylene (PE), polyvinyl chloride (PVC), and polyisobutylene (PIB). The foils are available in rolls in various widths. They should be fitted with a 30cm overlap and run up the wall up to 2cm above the final floor height.
Levelling The extent to which unevenness in the base shows up in the finished floor varies partly with the hardness or density of the floor. Small patches of unevenness in the screed will not usually show through with laminate or parquet. In those cases a flexible subfloor with or without
