When deciding whether to use Glass or Rock Mineral Wool, Bradley Hirst, Technical Services Manager from Knauf Insulation, explains that you need to take performance and application into account.
Thermal performance
If thermal performance is the primary consideration, such as when insulating masonry cavity walls, choose Glass Mineral Wool. Some products can achieve a lambda value of 0.032 W/mK, compared to a best of 0.034 W/mK for Rock Mineral Wool.
Fire safety
Mineral Wool is non-combustible under the Euroclass reaction to fire classification system, so will not contribute to the development or spread of fire, making it the safest option at any height.
Where fire resistance is required, such as in the separating floor of a loft conversion, Rock Mineral Wool is more suitable. With a melting temperature of over 1,000ºC, it minimises heat transfer giving occupants time to escape. Always choose products developed and tested for fire resistance.
Noise reduction
Mineral Wool is the best insulant when it comes to absorbing sound. Many people believe Rock Mineral Wool performs better than Glass Mineral Wool because of its higher density. Our tests show that both perform equally well in real world buildings.
Robustness
Rock Mineral Wool has superior compressive strength than Glass Mineral Wool. This makes it suitable for use in applications such as warm flat roofs where robustness is required.
Comfort
Another consideration is installer comfort. Mineral Wool products manufactured with ECOSE Technology, Knauf Insulation’s unique bio-based binder, contain no added formaldehyde or phenol. They are soft to touch, easy to handle, generate low levels of dust and VOCs, and have been awarded the Eurofins Gold Certificate for Indoor Air Comfort. Knauf Insulation’s Glass Mineral Wool product range has also been accredited as DECLARE ‘Red List Free’ label. This provides a straightforward ingredients list, together with information about embodied carbon and product life expectancy.
To find the right Mineral Wool product for your application, download the new Knauf Insulation Solutions guide at www.knaufinsulation.co.uk/solutions-guide
