Creating calm: noise has a major impact on our well-being
It is one of the challenges for Unilin Group in its One Home sustainability strategy: developing products that contribute to a wholesome, comfortable and sustainable living environment for our customers. In a world where more and more people live and work in close proximity to each other, it is important to give acoustics careful consideration. Professor Edwin Reynders of the Catholic University of Leuven (KUL) confirms that working on improved sound insulation and good acoustics is necessary to safeguard our mental health.
Edwin Reynders specialises in building mechanics and building acoustics. His research team frequently works with industrial partners to develop better solutions in terms of building acoustics. Limiting the health risks of noise and guaranteeing the acoustic functionality of buildings are among the most important reasons to continue to innovate and carry out research.
Noise and stress
Edwin Reynders: “Many studies look into the impact of noise on well-being. Noise issues in buildings are becoming more frequent because we live and work so close to each other. Both Flemish and European research has shown that approximately one in three suffer from noise pollution at home.” This leads to health risks.
“These health risks usually manifest themselves as stress, sleeping problems and sleeplessness. With noisy neighbours, for instance, you can add social tensions to the list. Law enforcement statistics show that noise from neighbours is by far the most common complaint.” In other words, the impact of noise on how we feel should not be underestimated.
Sound absorption vs. sound insulation
Looking at the construction industry, professor Reynders identifies two groups of acoustic problems: problems with sound absorption and problems with sound insulation. “Sound reverberation in a room is an example of bad sound absorption. From a technical standpoint such issues are usually easier to solve, for instance by using a material in that space that absorbs the surplus of sound, making the space much calmer and quieter.”
The second group of acoustic issues is somewhat trickier: the ones involving sound insulation, whereby sound is carried over from one space to the next. “Contrary to thermal insulation, sound can’t be insulated with a single material but requires a specific floor or wall structure.” As a result, these issues are much more complex.
Sound insulation problems come in two types: issues involving impact noise or airborne noise. “Impact noise is the result of vibrations generated by direct contact with a wall or floor e.g. by walking on it. Reduce the vibrations and you reduce the impact noise. Broadloom carpet can help to a certain extent. Changing the structure of your floor makes it possible to reduce impact noise: install a supple anti-vibration material between the screed and the subfloor. The golden rule: the thicker and more supple the material and the heavier the screed and subfloor, the more effective the insulation."
However, that makes your floor much more expensive and that is why flooring manufacturers such as Unilin Group keep looking for affordable solutions that offer the same results. The R&D teams at both Unilin Flooring and Unilin Insulation aim to develop superior products that take increasing account of the impact of noise. Kristof Van Vlassenrode works as an R&D Director at Unilin Flooring. Kristof and his team specialise in vinyl flooring, amongst others LVT (luxury vinyl tiles). “As professor Reynders indicated, the structure of the floor as a whole is important, including the underlay. Our systems seek to minimise impact noise and foster sound absorption. Our carpet tiles score exceptionally well on both aspects.”
Kristof’s team is also making headway in the area of vinyl tiles. "We have found that positioning the foam layer in harder vinyl closer to the top layer yields a spectacular reduction in noise level. For Loose Lay LVT we recently developed an acoustic product with a built-in foam sublayer.”
Don’t forget about sound absorption
It strikes Edwin Reynders that neither sound insulation nor sound absorption receive the attention they deserve in construction projects. “For instance, the use of finishing materials with very limited sound absorption qualities is still common practice. Think of a poured concrete floor, glass panels everywhere, plastered walls... with these materials larger spaces in particular have a lot of echo, which is highly unpleasant.”
Unilin Group develops products that focus on sound absorption. One of the products that do particularly well in this area is Unilin Insulation’s Usystem Roof DS Acoustic roofing element. Product manager roof panels Peter Benkö is enthusiastic: “This innovation boasts incredible values of up to 85% sound absorption.” The product was successfully applied in Hangar K in Kortrijk, an erstwhile hangar that was converted into office space, and in the Cotton Factory in Kortrijk, an old velvet factory that was repurposed as a business centre.
Unilin Insulation not only focuses on thermal insulation but also develops products that offer better insulation against sounds from outside. This involves the installation of rock wool on the outside. “This way we can help improve sound insulation with a product you have to use anyway”, Peter concludes.
Much work to be done
Renovations isn’t the only area where much work remains to be done in the development of affordable systems. Sustainable construction systems such as timber frame construction face the same challenge. Edwin Reynders: “This is because wood is a lightweight material which, by nature, has far less sound insulating properties. That is the major challenge: finding the balance between affordability and innovation. It is possible to install a heavily reinforced wooden floor with a thickness of 60 cm but this obviously comes at a price.” Challenge accepted...
Professor Edwin Reynders is a member of the faculty of Engineering Sciences at the Catholic University of Leuven (KUL) and specialises in building mechanics and building acoustics. Acco recently published a Dutch reference work by his hand entitled ‘Bouwakoestiek’ (Building Acoustics).
Unilin Group is constantly looking for the next innovation.