Underlays are the kind of products that we buy extremely rarely, so we usually don’t have our own experience of choosing and properly selecting an underlay for our needs. Even if this is not our first ever purchase of such a product, it might have been several years since the last time. We may have already forgotten how it happened… In addition, technology is advancing all the time – new and improved products appear almost every year. Therefore there are many myths, outdated beliefs or even misleading information materials available on the market. One of these myths is that the underlay we choose is the same one in every case, regardless of our needs. The parameters described in EN 16354 are an attempt to convince the market that this is not the case. Just as you can buy different kind of floors – dedicated to different rooms – we also select an underlay according to the type of room and our needs. The result of this myth is the availability of different types of polyethylene foams (foams with foil, foams with holes or in different colors) or even corrugated cardboard. According to the standard, the PE foam cannot be named as an underlay as it does not meet the requirements. If we want our floor to last several years in the same condition, we shouldn’t choose foam – choose products that meet the standards. Another very harmful myth is the one related to underfloor heating saying that an underlay for underfloor heating should have holes. NO! Air is an insulator and conducts heat very poorly, which will increase your bills. Large holes in the underlay (more than 0.5 cm in diameter) are also a big danger for the panels. The voids cause the panels to bow, damaging the locks over time and creating gaps in the panels. If you are not sure if the product you are about to buy is the right solution, look for the technical data sheet (TDS). If the sheet has only perfunctory information, a few basic parameters or does not indicate the standards – it’s a clear signal that you should be vigilant. A professional, good product comes with a sheet which indicates several parameters tested according to PN, EN or ISO standards.