Mineral wool consists of spun yarn made of melted glass (glass wool) or stone (rock wool). Mineral wool insulation offers excellent thermal and acoustic performance properties and the flexible, robust composition is ideal for warm roofs, loft conversions and cold roofs at joist level. Suitable for conditions and applications where the material may be compressed, mineral wool insulation is usually sold in rolls, and is available in varying thicknesses and widths. The current recommended depth for loft insulation is 270 millimetres for glass wool and 250 millimetres for rock wool.
We stock both glass wool and rock wool from leading manufacturers Knauf and ROCKWOOL. They are very similar insulation materials but there are some key differences. Glass wool has long fibres, high fire resistance, low elasticity and tensile strength and a melting temperature of 1000°C. Rock wool, on the other hand, has short fibres a slightly lower fire resistance, high elasticity and tensile strength and a melting temperature of 700°C.
Knauf Earthwool Loft Rolls are non-combustible, glass mineral wool rolls, that have been manufactured using their revolutionary ECOSE® Technology that contains no added formaldehyde or phenols. It comes in a lightweight quilt for easy installation with thermal conductivity of 0.044 W/mK. Knauf Rafter Insulation Roll is designed for use in warm roofs where pitched roofs are insulated at rafter level and will significantly enhance the acoustic performance of the roof, which is of particular importance in attached and terraced dwellings.
ROCKWOOL Roll is made up of medium density mineral wool insulation. The thermal insulation boasts acoustic properties and is fire resistant, rated A1 Euroclass non-combustible. This insulation solution is suitable for horizontal roof application in all building types or can be used as an acoustic absorber in suspended ceilings. ROCKWOOL HARDROCK Multi-Fix is manufactured from renewable volcanic stone which produces a non-combustible roofing insulation board. The boards are compatible with a range of flat roof systems, including single-ply, EPDM and liquid membranes, bitumen, and green roofs.
While there are many advantages to using mineral wool insulation, the installation process must be carried out by a professional or by someone with the correct protective equipment. This is because inhaled slivers of mineral wool irritate the alveoli and can cause lung disease. Contrary to glass wool, rock wool insulation does not cause that much skin irritation. In terms of environmental friendliness, however, glass wool performs better. Mineral wool insulation may also start to sink, compress and sag as it ages which is why we would recommend laying slightly more than guidelines suggest to allow for settling.