12th July 2017

Glass Mineral Wool: The Sound Approach to Acoustic Comfort

In the UK, around 90 per cent of people’s time is spent indoors, with 65% of this spent at home. This means that ensuring indoor spaces are comfortable to live in should be of the utmost importance for housebuilders. Here, Jol Berg, Head of Technical at Isover UK, discusses how to improve acoustic comfort through careful selection of insulation products.

While homeowners often relate comfort to characteristics like warmth and dryness, well-balanced acoustics are crucial to the usability of a space as unwanted noise can be detrimental to health and wellbeing.

Sound from noisy neighbours, TVs, speaker systems is a nuisance for occupants in adjoining properties or other rooms – especially if walls aren’t sufficiently insulated.

In England and Wales, acoustic performance is covered by Part E of the Building Regulations, which sets the minimum standards for sound reduction and absorption qualities in new structures. However, as is often the case when any minimum value is stipulated, there is a tendency to use this minimum performance as a target performance.

Isover has a range of acoustic solutions for separating walls, internal walls and internal floors designed to help surpass these regulations.

For example, the minimum requirement for a separating wall in a new dwelling in England and Wales is to reduce airborne sound by 45dB.  Building to any of Isover’s tried and tested proprietary Robust Details (e.g. E-WM-17, E-WM_20 or E-WM24) will achieve airborne sound reduction of at least 50dB, which represents a significant improvement beyond building regulations and will have a meaningful positive impact on the acoustic comfort of the building residents.

Many incorrectly believe that high mass, such as a solid concrete wall, is the most effective barrier to unwanted noise. While this type of construction may be effective for absorbing lower frequencies, the solid characteristics can act as a sound transmission medium for other frequencies such as conversations, household appliances, or power tools.

A more effective way of preventing unwanted noise is the ‘mass – spring – mass’ solution. This involves the use of heavy materials, such as masonry or plasterboard, to form two layers of ‘mass’ that sandwich a layer of mineral wool insulation – the ‘spring.’

That’s where Isover APR (1200) and RD Party Wall Roll come in. While mineral wool insulation is commonly recognised for its thermal properties by minimising heat loss and making buildings more energy efficient, when used in the mass – spring – mass system, it can significantly improve the acoustic performance of those systems.

The type of insulation used here is important, as it is often assumed that all products have similar properties. Other insulation, such as PIR, doesn’t share the same sound-deadening properties as mineral wool, so shouldn’t be considered for acoustic applications. Mineral wool loft insulation shouldn’t be used either since the density of this type of product is usually too low to achieve desired levels of acoustic performance, and the thickness and roll dimensions are not optimised for acoustic applications.

Isover’s acoustic insulation is manufactured to be at the optimum density and product dimensions for effectively dampening sound and reducing its transfer between walls, floors and ceilings.   

As little as 50mm thickness of Isover APR (1200) in a stud wall can significantly reduce the transfer of sound through a metal or timber stud partition.  In certain partitions this can improve the sound reduction of the partition to 44dB.  This represents a significant improvement above Building Regulations minimum standards (40dB) for a relatively modest cost.  As with the above separating wall example, this would also result in a significantly improve the acoustic quality of the buildings that people work and live in.

Incorporating acoustic insulation at the specification stage can make a significant improvement in terms of creating a quiet peaceful environment for a building’s user, to allow them to live the way they want to in their home without worry of noise travelling from room to room or house to house.