{"title":"Knauf Rocksilk RS45","description":"","products":[{"product_id":"25mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"25mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eRS45 is the standard-density member of the Rocksilk® family, and that is a recommendation rather than a caveat. Plenty of constructions need rock mineral wool for its fire and acoustic behaviour without needing the mass that the heavier slabs carry, and specifying up the density ladder when the job does not call for it simply costs more.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e25mm Knauf Rocksilk® RS45 has a thermal conductivity of 0.035 W\/mK, giving a thermal resistance of 0.70 m²K\/W*. Slabs measure 1200mm x 600mm and are supplied 20 per pack, covering 14.40m², the widest pack coverage anywhere in the Rocksilk® range.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eWorth knowing when comparing: RS45 sits at 0.035 W\/mK while the denser Rocksilk® slabs run at 0.034 W\/mK, so the heavier products do carry a marginal thermal edge. It is small, and it is not usually the reason anyone chooses between them.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eStandard-density rock mineral wool slab at 45 kg\/m³\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 0.70 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 20 per pack covering 14.40m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWidest pack coverage in the Rocksilk® range\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 to BS EN 13501-1\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eManufactured with ECOSE® Technology bio-based binder\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMulti-application across thermal, fire protection and acoustic use\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e12 packs per pallet\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWhere a specification names a density, check it: RS45 is 45 kg\/m³, and the denser Rocksilk® slabs are not interchangeable with it\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eAt 25mm the slab is usually a supplementary layer rather than the main insulation\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSlabs should be closely butted so the layer stays continuous\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCuts easily to size with a large-bladed knife or saw\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSupplied in recyclable 4-LDPE polythene packs\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eStore indoors or under cover and off the ground; never leave permanently exposed\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W. Knauf does not publish a declared R-value table for Rocksilk® Building Slabs.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655604531534,"sku":"BM002988","price":39.32,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-25mm-bm002988-mineral-fibre-insulation-1172607643.jpg?v=1749583798"},{"product_id":"30mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"30mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eBuilt-up metal roofs and walls are one of the applications Knauf lists for Rocksilk® Building Slabs, and 30mm is a common liner depth within them. It is a construction where non-combustibility is not a nice-to-have: metal-clad industrial and commercial envelopes come under scrutiny for fire performance, and rock mineral wool answers that at material level.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e30mm Knauf Rocksilk® RS45 is classified Euroclass A1 to BS EN 13501-1, the highest reaction to fire classification available. Slabs are 1200mm x 600mm and supplied 16 per pack, covering 11.52m². Thermal conductivity is 0.035 W\/mK, giving a thermal resistance of 0.85 m²K\/W*.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eThe same slab is listed for pitched roofs between rafters, intermediate and separating floors, internal stud partitions and light steel frame infill, so a single product covers several elements of a building rather than one.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eListed by Knauf for built-up metal roofs and walls\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 to BS EN 13501-1\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 0.85 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 16 per pack covering 11.52m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDensity of 45 kg\/m³\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eOne slab specification across roofs, floors, partitions and frame infill\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eManufactured to BS EN 13162\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eContains no ozone-depleting substances or greenhouse gases\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eReaction to fire describes the material; any fire resistance period belongs to the tested system\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eConfirm the build-up against the system specification before substituting\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eKeep slabs tightly butted with no gaps at joints or perimeters\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eRock mineral wool has a melting temperature above 1000°C\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eNot a decorative surface\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCover slabs and keep them off the ground while stored on site\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655605219662,"sku":"BM002992","price":40.26,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-30mm-bm002992-mineral-fibre-insulation-1172607640.jpg?v=1749583689"},{"product_id":"40mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"40mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eLight steel frame infill is unforgiving of insulation that will not conform. Steel sections are dimensionally precise but the assembled frame rarely is, and rigid boards leave a gap wherever the two disagree. Rock mineral wool takes a different approach: it adapts to slight imperfections in the substrate and knits together with the slab beside it, closing the air gaps that undermine performance in practice.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e40mm Knauf Rocksilk® RS45 is a rock mineral wool slab at 45 kg\/m³, sized 1200mm x 600mm and supplied 12 per pack covering 8.64m². Thermal conductivity is 0.035 W\/mK, giving a thermal resistance of 1.10 m²K\/W*.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eKnauf makes the point directly in its own literature: the absence of air gaps is what determines whether insulation delivers in the building rather than only in the calculation.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eAdapts to slight imperfections in the substrate and knits together, eliminating air gaps\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eListed by Knauf for light steel frame infill\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 1.10 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 12 per pack covering 8.64m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDensity of 45 kg\/m³\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 non-combustible\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEasier to install correctly than rigid board alternatives\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e12 packs per pallet\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMeasure the actual bay width before cutting, as assembled frames vary from the drawing\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCut slightly generous rather than tight so the slab knits against the framing\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFill fully around noggins, services and penetrations rather than working around them\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eOdourless, rot proof and non-hygroscopic\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMade with ECOSE® Technology, containing no added formaldehyde or phenol\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003ePacks give short-term protection only; store under cover for anything longer\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655605449038,"sku":"BM004209","price":37.85,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-40mm-bm004209-mineral-fibre-insulation-1172607637.jpg?v=1749583682"},{"product_id":"50mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"50mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eMost internal stud partitions get insulated for two reasons at once: to hold heat where it is wanted and to stop conversations travelling between rooms. 50mm Knauf Rocksilk® RS45 does both jobs from one slab, which is why it is the depth that moves in the greatest volume across the range.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eSlabs measure 1200mm x 600mm and are supplied 10 per pack, covering 7.20m². Thermal conductivity is 0.035 W\/mK, giving a thermal resistance of 1.40 m²K\/W*.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eThe acoustic side comes from the material rather than the thickness. Knauf states that mineral wool provides the best levels of sound absorption and reduction compared with other mainstream insulants, and a partition filled edge to edge with it behaves very differently from one filled with a rigid board or left empty.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal and acoustic performance from a single slab\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMineral wool offers the best levels of sound absorption and reduction among mainstream insulants\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eListed by Knauf for internal stud partitions\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 1.40 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 10 per pack covering 7.20m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDensity of 45 kg\/m³\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 non-combustible\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eAwarded the Eurofins Gold Certificate for Indoor Air Comfort\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInsulation reduces sound transmission as part of a partition; it does not soundproof a room on its own\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSound reduction figures belong to the tested partition, so work to the system specification\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGaps at the head, base and around sockets undo acoustic performance quickly\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSlab depth should match the stud depth being filled\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGenerates low levels of dust and VOCs\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eStore under cover, off the ground and out of the weather\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655605711182,"sku":"BM004208","price":38.68,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-50mm-bm004208-mineral-fibre-insulation-1172607634.jpg?v=1749583572"},{"product_id":"60mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"60mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003ePitched roof constructions between rafters are one of the applications Knauf lists for Rocksilk® Building Slabs, and 60mm is a depth that suits shallower rafter sections without needing a second layer to make up the difference.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e60mm Knauf Rocksilk® RS45 measures 1200mm x 600mm and is supplied 8 per pack, covering 5.76m². Thermal conductivity is 0.035 W\/mK, giving a thermal resistance of 1.70 m²K\/W*.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eRafter spacings are among the least consistent dimensions on any older roof, which is where the practical advantage sits. The slab is lightweight and cuts easily to size, so working along a run of irregular bays is a matter of measuring and trimming rather than fighting a board into a space it was never sized for.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eListed by Knauf for pitched roof constructions between rafters\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 1.70 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 8 per pack covering 5.76m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eLightweight and easily cut to size for irregular bays\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDensity of 45 kg\/m³\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 to BS EN 13501-1\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWater vapour resistivity of 5.00 MNs\/g.m\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eManufactured under ISO 9001, ISO 14001 and ISO 50001 systems certified by TÜV Nord\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMeasure each bay individually on an older roof rather than assuming a consistent spacing\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eVentilation and condensation control in a pitched roof are design matters; check the specification\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSlabs should sit snugly against the rafters with no gaps at the edges\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDo not compress the slab into a shallower space\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWill not sustain vermin or encourage the growth of fungi, mould or bacteria\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eNever leave slabs permanently exposed to the elements\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655606956366,"sku":"BM005820","price":36.86,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-60mm-bm005820-mineral-fibre-insulation-1172607631.jpg?v=1749583563"},{"product_id":"75mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"75mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eIntermediate floors are where a house or an office building gets noisy, and 75mm Knauf Rocksilk® RS45 is specified into the joist void to deal with it. Knauf lists intermediate floors and separating floors among the applications for Rocksilk® Building Slabs, alongside partitions, rafter-level roof work and frame infill.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eSlabs are 1200mm x 600mm and supplied 6 per pack, covering 4.32m². Thermal conductivity is 0.035 W\/mK, giving a thermal resistance of 2.10 m²K\/W*.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eA floor void is not somewhere anyone wants to revisit. Knauf states that the product will have a life equivalent to that of the wall structure in which it is incorporated, so once the deck goes down the insulation is settled: no slumping into the bottom of the void, no degradation, no voids opening up over the joist runs years later.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eListed by Knauf for intermediate and separating floors\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eLife equivalent to that of the structure it is incorporated into\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 2.10 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 6 per pack covering 4.32m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDensity of 45 kg\/m³\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 non-combustible\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEnvironmental Product Declaration S-P-02700 published for the product\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e12 packs per pallet\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSlab depth should suit the joist depth; a 75mm slab is not a full fill of a deeper void\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTake care to fill right up to the joists so no gaps run the length of the floor\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eImpact and airborne sound are separate problems and are addressed differently in a floor build-up\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHandle slabs without crushing edges and corners\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eRot proof and non-hygroscopic\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eStore indoors or under cover and off the ground\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655607382350,"sku":"BM003227","price":33.76,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-75mm-bm003227-mineral-fibre-insulation-1172607628.jpg?v=1749583455"},{"product_id":"100mm-knauf-rocksilk-rs45-building-slab-1-2m-x-600mm","title":"100mm Knauf Rocksilk RS45 Building Slab  1.2m x 600mm","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e100mm is the deepest Rocksilk® RS45 slab in this range and the one specified into separating floors, deeper joist voids and full-depth frame infill. Slabs measure 1200mm x 600mm and are supplied 5 per pack, covering 3.60m², with 12 packs to a pallet. Thermal conductivity is 0.035 W\/mK, giving a thermal resistance of 2.85 m²K\/W*.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eAt this depth the slab is often working in a floor or a roof void where moisture and long-term stability are as relevant as the thermal figure. Rocksilk® Building Slabs are non-hygroscopic and rot proof, with a water vapour resistivity of 5.00 MNs\/g.m, and they will not sustain vermin or encourage the growth of fungi, mould or bacteria.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003eKnauf also confirms the slabs contain no ozone-depleting substances or greenhouse gases, with environmental performance reported under EPD S-P-02700.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eBenefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eDeepest Rocksilk® RS45 slab in this range at 100mm\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal conductivity of 0.035 W\/mK\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eThermal resistance of 2.85 m²K\/W*\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e1200mm x 600mm slabs, 5 per pack covering 3.60m²\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e12 packs per pallet\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eNon-hygroscopic, rot proof and will not sustain vermin\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eWater vapour resistivity of 5.00 MNs\/g.m\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eEuroclass A1 to BS EN 13501-1\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eContains no ozone-depleting substances or greenhouse gases\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e\u003cstrong\u003eGood to know\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"auto\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSlab thickness should match the depth of the void or framing it fills\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCompressing the slab into a shallower space means it will not perform as calculated\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eContinuity matters as much as depth: butt slabs closely and fill right to the framing\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eRocksilk® RS45 is also produced at 150mm if a deeper section is required\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eNot a decorative surface\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCover slabs, keep them off the ground and protect from the weather on site\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"auto\"\u003e*Thermal resistance calculated from the declared thermal conductivity using Knauf's stated method: thickness in metres divided by lambda, rounded down to the nearest 0.05 m²K\/W.\u003c\/p\u003e","brand":"Knauf","offers":[{"title":"Default Title","offer_id":52655607644494,"sku":"BM003428","price":36.86,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/1083\/0670\/files\/knauf-knauf-rocksilk-rs45-building-slab-1200mm-x-600mm-600-x-1200-x-100mm-bm003428-mineral-fibre-insulation-1172607625.jpg?v=1749583447"}],"url":"https:\/\/www.insulationuk.co.uk\/collections\/knauf-rocksilk-rs45.oembed","provider":"Insulation UK","version":"1.0","type":"link"}