{"product_id":"tapered-pir-roof-insulation-board-flat-roof-drainage-fall-system-3-thickness-bands","title":"Tapered PIR Roof Insulation Board – Flat Roof Drainage Fall System, 3 Thickness Bands","description":"\u003cp\u003eA flat roof is never actually flat — it needs a fall, or every rain shower leaves ponding water sitting on the membrane, feeding the exact leaks and premature failures that keep our repair-kit range in business. Rather than building falls into the deck structure itself, tapered insulation boards do the job at insulation level: each board's thickness increases steadily across its width so, laid in sequence, they create a consistent drainage fall while insulating the roof.\u003c\/p\u003e\n\u003cp\u003eThis is the same PIR foam core and mineral-glass-fibre facing as our standard flat PIR board — the difference is purely geometric: constant thickness for pure U-value, or tapered for drainage fall plus U-value in one layer.\u003c\/p\u003e\n\u003ch3\u003eSpecification\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eProperty\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCore material\u003c\/td\u003e\n\u003ctd\u003ePIR (polyisocyanurate) rigid foam\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFacing\u003c\/td\u003e\n\u003ctd\u003eMineral-glass-fibre coated facers, both sides\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFall\u003c\/td\u003e\n\u003ctd\u003eStandard 1:60 taper\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBoard size\u003c\/td\u003e\n\u003ctd\u003e1200 x 1200mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThickness bands\u003c\/td\u003e\n\u003ctd\u003e30-50mm (Pack of 6, 8.64m²), 50-70mm (Single Board, 1.44m²), 70-90mm (Pack of 4, 5.76m²)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eWarm and cold flat roof build-ups needing a drainage fall to outlets\/gutters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eOrdering guidance\u003c\/h3\u003e\n\u003cp\u003eTapered schemes are normally laid out board-by-board along the fall direction toward your roof outlets — for anything beyond a simple single-direction fall, have your roofer or a tapered-insulation designer confirm the board layout and thickness sequence for your specific roof geometry before ordering. This range complements our standard \u003ca href=\"\/products\/pir-insulation-board-foil-faced-2400-x-1200mm\"\u003ePIR Insulation Board\u003c\/a\u003e (constant thickness, for roofs where fall is already built into the deck) and pairs with our \u003ca href=\"\/products\/polythene-vapour-control-layer-vcl-4m-x-25m\"\u003ePolythene Vapour Control Layer\u003c\/a\u003e and \u003ca href=\"\/products\/pvc-single-ply-roofing-membrane\"\u003ePVC Single-Ply\u003c\/a\u003e or \u003ca href=\"\/products\/epdm-rubber-roofing-supplies\"\u003eEPDM membrane\u003c\/a\u003e ranges to complete a warm roof build-up.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need this instead of standard PIR board?\u003c\/strong\u003e Only if your roof needs a built-in drainage fall. If your deck already falls to outlets, standard constant-thickness PIR board is usually the simpler, cheaper choice.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat does \"1:60 fall\" mean?\u003c\/strong\u003e A 1:60 fall rises 1mm in height for every 60mm of horizontal run — the standard minimum fall recommended for most flat roof membranes to avoid ponding.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I get thicker bands than 90mm?\u003c\/strong\u003e Wider thickness bands (90-150mm) exist in this range from the manufacturer but were out of stock everywhere we checked at time of publishing — get in touch and we'll source and quote them for you.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes thickness affect U-value as well as fall?\u003c\/strong\u003e Yes — because the boards taper, the average thickness (and therefore average U-value) varies across a scheme; a proper tapered layout calculation accounts for both fall and U-value together.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I cut boards to fit?\u003c\/strong\u003e Yes, PIR tapered boards can be cut on site, but cutting across the taper changes the fall gradient at that point — plan cuts along the taper direction where possible.\u003c\/p\u003e","brand":"Rubber Roof UK","offers":[{"title":"30-50mm (Pack of 6, 8.64m²)","offer_id":46014839390399,"sku":"TPIR-30-50-P6","price":588.7,"currency_code":"GBP","in_stock":true},{"title":"50-70mm (Single Board, 1.44m²)","offer_id":46014839423167,"sku":"TPIR-50-70-1BD","price":155.76,"currency_code":"GBP","in_stock":true},{"title":"70-90mm (Pack of 4, 5.76m²)","offer_id":46014839455935,"sku":"TPIR-70-90-P4","price":507.8,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0598\/1804\/9727\/files\/tapered-pir-insulation-boards-flat-roof-drainage-fall.jpg?v=1786783256","url":"https:\/\/rubberroofuk.uk\/products\/tapered-pir-roof-insulation-board-flat-roof-drainage-fall-system-3-thickness-bands","provider":"Rubber Roof UK","version":"1.0","type":"link"}