Here you will find a number of questions that we have received in the past, together with the answers. In case your question is not mentioned here and you are unable to find an answer on this website, please do not hesitate to fill out the e-mail contact form, send an e-mail to info@unifloor.nl or give us a call at +31 570 85 55 33. When you are calling from the UK, you may dial 0845 603 0 906.

What is meant by sound reduction of flooring?
The way sound reduction is measured is by comparing the noise that penetrates a bare floor, meaning without any floor covering; to a fully installed floor with underlay and finished floor covering. When you see a figure indicating the level of sound reduction by an underlay, this figure has almost always been obtained in combination with a specific type of floor covering, for example laminate. This does not automatically mean that the same degree of sound reduction will be obtained when this underlay is used in combination with for instance a wooden floor! There are even manufacturers who only mention a “bare” test of the underlay on its own. This does not give any guarantee on how the sound reduction will be after a floor covering has been put on top!

What regulations are currently in force with regards to impact noise reduction?
At this moment the European norms EN-ISO 140-8 and EN-ISO 717-2 are in force, they have also been implemented in all countries belonging to the European Union. For the Netherlands the norm is now NEN-EN-ISO 140-8 / 717-2, for the United Kingdom it is BS-EN-ISO 140-8 / 717-2 and for France FR-EN-ISO 140-8 / 717-2.

What is the difference between a ΔLlin and a ΔLw measurement?
An ΔL measurement indicates the improvement in impact noise reduction by a floor finish or floor covering, measured according to EN-ISO 140-8. It is the difference in the noise level that penetrates a floor when it is bare and when it is completely covered with an underlay and floor covering. In Europe the ΔLw norm is used, which means the the noise is measured between the frequencies 315 Hz and 2500 Hz.
In the Netherlands however it has been decided to use a wider band, i.e. starting from 100 Hz. This is done so the real low noise is also measured; these frequencies penetrate a flooring construction far deeper and stronger. As a consequence, the noise reduction value is lower than normally. Therefore a new testing value has been chosen; ΔLlin. This value is only applicable in the Netherlands. In general, the difference between a ΔLw figure and a ΔLlin figure is 10 to 11 dB.