Manufacturers advertise values between 20 and 40 dB – but without stating the test standard, these figures cannot be compared. This page explains which standards lie behind the dB figures, what a sound reduction index of 23 dB actually means and why the effect on a construction site differs from laboratory values.
Sound insulation vs. sound absorption
- Sound insulation (weighted sound reduction index Rw or DLR) describes how much sound the mat holds back. Tested using the sound intensity method of the ISO 15186 series (Part 1: laboratory, Part 2: field/in situ measurement) or to EN ISO 10140 (laboratory), rated in accordance with EN ISO 717-1. The test report states which method a given value is based on.
- Sound absorption (DLα, classes A0–A5) describes how much sound the surface absorbs rather than reflects. Tested to EN 1793-1 or EN ISO 354; relevant for avoiding reflections towards the opposite side.
- EN 1793-2 rates the airborne sound insulation of road traffic noise barriers (classes B0–B4), while EN 1793-3 defines the normalised traffic noise spectrum.
What does a “23 dB sound reduction index” mean?
Our Premium noise barrier mats achieve a weighted sound reduction index of 23 dB (test report to ISO 15186, sound intensity method). This is the value of the mat itself when installed over the full area, tightly sealed, in the tested configuration. On site, what counts is the insertion loss: sound diffracts over the top edge and around the ends of the barrier, joints and gaps let sound through, and the distances between source, barrier and receiver determine the shielding angle. Realistically, this results in a level reduction of 10 to 15 dB(A) at the site boundary – still a halving to quartering of the perceived loudness. Our noise barrier calculator illustrates this relationship.
Fire behaviour
The reaction to fire of construction products is classified to EN 13501-1 (Euroclasses A1 to F, e.g. B-s2,d0 for flame-retardant with low smoke production); in Germany, DIN 4102 (B1 flame-retardant) is still in common use. For scaffold sheeting, the German construction trade association BG BAU additionally requires the “flame-retardant” rating. Certificates for our product variants are available on request.
Which standard does the authority require?
The following refers to regulations in Germany; other countries apply their own limit values. The AVV Baulärm (German general administrative regulation on construction noise) does not specify a product standard but sets immission guide values at the receiver location. For noise control concepts, a test report to ISO 15186 or EN ISO 10140 stating the weighted sound reduction index, together with a prediction of the insertion loss, is usually sufficient. Workplaces are governed by the LärmVibrationsArbSchV (German noise and vibration occupational safety ordinance), whose action values are explained by the BAuA (Federal Institute for Occupational Safety and Health).
Frequently asked questions about standards and dB values
What does a sound reduction index of 23 dB mean?
It is the weighted sound reduction index of the mat in the tested configuration: the sound level behind the mat is 23 dB lower than in front of it – with full-area, tightly sealed installation and without diffraction over the edges. The test report states the test method (ISO 15186 Part 1 laboratory / Part 2 in situ).
What is the difference between insulation and absorption?
Insulation holds sound back (transmission), absorption soaks up sound at the surface (reflection). Noise barrier mats must above all insulate; absorption additionally reduces reflections towards the opposite side.
Why do I only achieve 10 to 15 dB on site?
Because of sound diffraction over the top edge, gaps at joints and ends, and the distance and height of the barrier. Taller, tighter barriers placed closer to the source deliver more.
What do classes such as B3 or A4 mean?
B classes (EN 1793-2) rate the airborne sound insulation of noise barriers (B3 = high), A classes (EN 1793-1) rate sound absorption (A4 = high).
Which standard does the authority require?
Usually no specific product standard; what is required is compliance with the immission guide values. A test report to ISO 15186 or EN ISO 10140 serves as proof of the mat’s performance.