280mm Knauf FactoryClad Roll 40 (Uncut) 3.45m x 1.2m - 4.14m2 per roll

280mm Knauf FactoryClad Roll 40 is a glass mineral wool insulation roll for built-up metal roof and wall systems, and the second deepest in the range. At this thickness the quilt is doing two jobs of comparable value. The thermal contribution is straightforward. The acoustic contribution is the one worth setting up properly, because how much of it you get depends on a decision made about the liner sheet rather than about the insulation. Each roll measures 3.45m by 1200mm and covers 4.14m², with 24 rolls to a pallet giving 99.36m². Declared thermal conductivity is 0.040 W/mK, giving a thermal resistance of 7.00 m²K/W, and water vapour resistivity is 5.00 MNs/g.m. Published embodied carbon is 2.42 kgCO₂e/m² across stages A1 to A3 and 3.21 kgCO₂e/m² across A1 to C4. Knauf's position is that mineral wool offers the best levels of sound absorption and reduction of any mainstream insulant, and that it reduces the reverberation of internal sound when used with metal liner sheets. The mechanism is worth understanding rather than taking on trust. Sound absorption needs the wool to be reachable: air has to be able to move into the open fibre structure, which means an acoustically open liner, perforated or micro-perforated. Behind a solid steel liner, sound largely reflects off the sheet and the quilt cannot absorb much of it into the space, though the added mass and depth still reduce sound passing through the assembly from outside or from plant above. Both outcomes are useful, but they are different problems and the liner choice decides which one you are solving. Knauf do not publish sound absorption coefficients for FactoryClad Rolls, so any acoustic design should work from figures for the actual build-up, supplied by the cladding system manufacturer or established by test. Installation is the standard build-up: liner sheet fixed, quilt laid over it, spacer system brought up to take it into the cavity, outer profiled sheet fixed last, to Knauf Insulation's guidance and the cladding system manufacturer's details. At 280mm the bracket system is specialist territory rather than catalogue, so confirm the depth with the system supplier before the order goes in. The depth suits wide-span industrial and commercial buildings where noise is a live consideration alongside heat loss, and on farms it applies where a building sits close to a dwelling or carries a planning condition on noise, with grain driers, extraction fans or ventilation plant running into the evening. Whichever the case, the U-value belongs to the assembly and wants calculating to BS EN ISO 6946:2017 or BS EN ISO 10211:2017 using BR443:2019. Key Benefits of Knauf FactoryClad Roll 40: Thermal resistance of 7.00 m²K/W at 280mm. Declared thermal conductivity of 0.040 W/mK. Euroclass A1 reaction to fire, non-combustible to BS EN 13501-1. 4.14m² per roll, and 99.36m² per pallet across 24 rolls. Unfaced on both faces, leaving the fibre structure open to work acoustically behind a perforated liner. Mineral wool gives the best levels of sound absorption and reduction among mainstream insulants, per Knauf. Depth and open structure also contribute to reducing sound passing through the assembly. 1200mm roll width to suit rail and bracket spacer systems. High tear strength for handling and for durability in service. Rot proof and non-hygroscopic, and will not sustain vermin or support fungal or mould growth. Bound with ECOSE® Technology, with no added formaldehyde or phenol. Good to know: Absorption needs an acoustically open liner: perforated or micro-perforated liner sheets let the quilt absorb sound into the space. Behind a solid liner it works on transmission instead. No published absorption coefficients: Knauf do not declare sound absorption figures for FactoryClad, so acoustic design should use figures for the specific build-up from the system manufacturer or from test. Specialist bracket depth: 280mm is beyond standard catalogue spacer systems, so agree it with the cladding system supplier before ordering. Available in the 40 grade only, as Roll 35 stops at 220mm. The 40 denotes a declared conductivity of 0.040 W/mK, not a thickness. Supplied uncut at 3.45m per roll. Non-hygroscopic, but not moisture resistant. Keep it dry and covered, and discard any roll that has taken water. At 280mm the thermal figure speaks for itself, and the acoustic return depends on getting the liner sheet decision right before the outer skin goes on.