Flat Roof Insulation
- Glass faced PIR boards
- Mineral wool slabs
- PIR boards with plywood
- Warm deck insulation
- For single ply or built-up
KNAUF, ROCKWOOL, CELOTEX, XTRATHERM, CELLECTA
The type of insulation used in a new flat roof is dependent on the roof specification. On a new concrete slab, with a screed, semi-rigid insulation boards such as expanded polystyrene board, extruded polystyrene board, glass fibre batts, mineral fibre batts, urethane foam board or phenolic foam board are laid under the roof covering. In a new timber structure, glass fibre quilt and mineral fibre quilt can be laid between the joists. In case of an existing flat roof, insulation can be increased externally with extruded polystyrene or foamed glass, or internally with an insulated lining board such as mineral fibre or polyurethane foambacked plaster-board.
- Cold roof
- Warm roof
- inverted roof
It is essential to understand the difference between those specifications to be able to install insulation in the right place to create a vapour barrier in the right area and prevent rotting of the roof joists.
A warm roof is when the insulation spans across the top of all the joists; it must be continuous and span over every joist. This means that any air rising from underneath would make the void between the joists warm hence a warm roof.
In a cold roof the insulation is put at the bottom of the joists or below the joists. This way sufficient ventilation is maintained which allows air to circulate above the insulation (below the roof). The void above the insulation should be at least 50mm thick. In this case the decking with the roof on it, which is above the joists, would be cold hence a cold roof.
Common mistake in the roof specification is when the insulation is installed inside the joists (close to the top part of the joists). This makes the roof neither cold nor warm, creating the void below the insulation. In this case there is no ventilation which makes the whole roof sweat and causes the joists to rot.
The inverted roof concept which is also known as protected membrane or upside down roofing. This method ensures insulating both the water proofing membrane and the reinforced concrete slab from extreme thermal stress. This is achieved by placing an extruded polystyrene thermal insulation board above, instead of below the waterproofing membrane and can be used for insulating flat topped buildings or balconies, retail or office developments, flats, hospitals, airports, hotels and residential housing in areas where roof is exposed to high temperatures.
Insulationshop.co offers a wide range of high density flat roof insulation from manufacturers such as Xtratherm, Celotex, Knauf, Kay Metzeler, Cellecta and more. For more information about particular products please see product description.
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59mm Plydeck Xtratherm (PIR with OSB Board) - 50mm PIR + 9mm OSB Board
2400x1200 - 2.88m2 show quantity discountsDelivery Time: 1 - 5 working days
Guide Price: £77.01 (£92.41 inc VAT)
£26.74/m2 (£32.09/m2 inc VAT)
show quantity discountsXtratherm Plydeck is a composite insulated panel of 50mm Xtratherm Polyisocyanurate core with a composite foil face, bonded to 9mm OSB board. The Xtratherm Plydeck provides a high level of thermal insulation and decking in one application.APPLICATIONPlydeck is designed to provide high levels of ther..
50mm Xtratherm Flat Roof Board FR-MG (pack of 10)
1200x600mm - 7.2m2 show quantity discountsDelivery Time: 1 - 2 days
Guide Price: £114.35 (£137.22 inc VAT)
£15.88/m2 (£19.06/m2 inc VAT)
show quantity discountsXtratherm FR-MG is a mineral coated glass faced board. Xtratherm XT/FR MG boards should be laid over the vapour control layer in a break bonded pattern. The long edges of the boards should be laid at right angles to the direction of the substrate and all edges must be fully supported by the deck. Th..
56mm Kingspan Thermaroof TR31 PIR bonded to Plywood (pack of 20) - 50mm PIR + 6mm Plywood Sheet
1200x2400 - 57.60m2 show quantity discountsDelivery Time: 3 - 5 days
Guide Price: £1,236.31 (£1,483.57 inc VAT)
£21.46/m2 (£25.75/m2 inc VAT)
show quantity discounts56mm Kingspan Thermaroof TR31 is the flat roof insulation comprising a 50mm high performance rigid PIR thermoset insulation core faced with an FSC certified 6 mm nominal thickness WBP exterior grade plywood on its upper surface and a low emissivity composite foil facing on its lower surfa..
96mm Recticel Plylok PIR Flat Roof Insulation Board - 90mm PIR + 6mm Plywood Sheet
1200x2400mm - 2.88m2 show quantity discountsDelivery Time: 1 - 5 working days
Guide Price: £131.60 (£157.92 inc VAT)
£45.69/m2 (£54.83/m2 inc VAT)
show quantity discounts96mm Recticel Plylok PIR Flat Roof Insulation Board is a rigid PIR board consisted of a few bonded elements contributing to its thermal performance and rigidity. The closed cell rigid 90mm PIR foam core is faced on both sides with multi-layer aluminium foil and bonded to 6mm WBP plywood. It is ..
96mm EcoTherm Eco-Deck - Insulated Flat Roof Decking
1200x2400mm - 2.88m2 show quantity discountsDelivery Time: 2 - 3 days
Guide Price: £114.09 (£136.91 inc VAT)
£39.61/m2 (£47.53/m2 inc VAT)
show quantity discounts96mm EcoTherm Eco-Deck is a tough, structural, pre-insulated thermal composite board for flat roofs. It comprises a 90mm thick fibre free polyisocyanurate (PIR) insulation core faced with 6mm thick tough, exterior grade plywood and is ready to fix and finish using basic tools and traditional roofing..
12mm Celotex TB4000 PIR Insulation Board - TB4012
1200x2400mm - 2.88m2
Guide Price: £24.18 (£29.02 inc VAT)
£8.40/m2 (£10.08/m2 inc VAT)
Celotex TB4012 is targeted at cut-to-fit applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation than has previously been possible. TB4012 is also appropriate for use in floors and walls. With low emissivity foil facings, TB4012 is manufac..
50mm Celotex Crown-Fix Flat Roof Board (pack of 24) - pallet of 2 packs
2400x1200mm - 138.24m2
Guide Price: £2,102.07 (£2,522.48 inc VAT)
£15.21/m2 (£18.25/m2 inc VAT)
50mm Celotex Crown-Fix is a brand new product for use in flat roof systems. Representing the next phase of Celotex innovation, Crown-Fix is a high performance rigid polyisocyanurate (PIR) insulation which delivers excellent dimensional stability and added robustness in a mechanically fixed single pl..
50mm Celotex Crown-Bond Flat Roof Board (pack of 11) -pallet of 12 packs
1200x600mm - 95.04m2
50mm Celotex Crown-Bond is a brand new product for use in flat roof systems. Representing the next phase of Celotex innovation, Crown-Bond is a high performance rigid polyisocyanurate (PIR) insulation which delivers cutting edge thinness, increased dimensional stability and added robustness in a bon..
100mm Celotex Crown-Up Flat Roof Board - pack of 6 - pallet of 12 packs
1200x600mm - 51.84m2 show quantity discounts
Guide Price: £1,593.81 (£1,912.57 inc VAT)
£30.74/m2 (£36.89/m2 inc VAT)
show quantity discounts100mm Celotex Crown-Up is a brand new product for use in flat roof systems. Representing the next phase of Celotex innovation, Crown-Up is a high performance rigid polyisocyanurate (PIR) insulation which delivers increased dimensional stability and added robustness in a built-up flat roofing system...
25mm Celotex FR5000 Fire Resistant PIR Insulation Board (pack of 16)
1200x2400mm - 46.08m2
Celotex FR5025 is one of the available dimensions of the Celotex FR5000 PIR insulation boards made from polyisocyanurate rigid core and faced on both side with low emissivity aluminum foils for improved thermal performance. The product is applicable to different types of constructions incl..
25mm Kingspan Thermaroof TR26 (pack of 12)
2400x1200mm - 34.56m2 show quantity discountsDelivery Time: 3 - 5 days
Guide Price: £402.36 (£482.83 inc VAT)
£11.64/m2 (£13.97/m2 inc VAT)
show quantity discounts25mm Kingspan Thermaroof TR26 is a high performance, fibre free, rigid thermoset PIR insulation core faced on both sides with a low emissivity composite foil facing which is used for insulating flat roofs and is fully compatible with most mechanically fixed single ply waterproofing systems and ..
25mm Kingspan Thermaroof TR27 (pack of 12)
25mm TR27 - 8.64m2 show quantity discountsDelivery Time: 3 - 5 days
Guide Price: £97.13 (£116.56 inc VAT)
£11.24/m2 (£13.49/m2 inc VAT)
show quantity discounts25mm Kingspan Thermaroof TR27 is a PIR insulation board made from highly effective rigid PIR core faced with coated glass tissue on both sides added during manufacturing. The product offers substantial durability and long life span depending on the condition of the supporting structure. Th..
25mm Kooltherm K7 Pitched Roof Board Kingspan (pack of 12)
K7 2400x1200 - 34.56m2
25mm Kingspan Kooltherm K7 Pitched Roof Board is the rafter/joist level insulation comprising a premium performance rigid thermoset phenolic insulation core faced on both sides with a low emissivity composite foil facing. This reflective, low emissivity surface improves the thermal resista..
30mm Kingspan Styrozone H350R Flat Roof XPS Board (pack of 14)
1250x600mm - 10.50m2 show quantity discounts
Guide Price: £74.38 (£89.26 inc VAT)
£7.08/m2 (£8.50/m2 inc VAT)
show quantity discountsKingspan Styrozone H350R Flat Roof XPS Board is highly effective rigid insulation board made from extruded polystyrene core covered with smooth skin on both sides. It is especially designed for protected membrane flat roofs, but is also used in green roofs as a popular alternative to tradi..
Kingspan Aquazone - Water Infiltration Reduction Membrane for Inverted Roofs
3m x 100m - 300m2 Delivery Time: 3 - 5 days
£566.21 (£679.45 inc VAT)
£1.89/m2 (£2.27/m2 inc VAT)
Kingspan Aquazone is a high performance non-woven polyethylene membrane suitable for use on inverted roofs finished with gravel ballast, green roof systems and concrete pavers on appropriate supports. Kingspan Aquazone can can dramatically minimise the cooling effect associated with rainwater f..
25mm Earthwool RS45 Universal Insulation Slab Knauf (pack of 20)
1200x600 - 14.4m2 show quantity discountsDelivery Time: 2 - 3 days
Guide Price: £41.63 (£49.96 inc VAT)
£2.89/m2 (£3.47/m2 inc VAT)
show quantity discounts25mm Earthwool RS45 Universal Slabs are unfaced, rock mineral wool slabs, available in a range of densities from 33 to 200 kg/m3. The standard product is supplied unfaced, but slabs can also be manufactured with a factory applied foil or tissue facing and are also available with a water repellent ad..
50mm Earthwool RS60 Universal Insulation Slab Knauf (pack of 9)
1200x600 - 6.48m2 show quantity discountsDelivery Time: 1 - 2 days
Guide Price: £41.63 (£49.96 inc VAT)
£6.42/m2 (£7.70/m2 inc VAT)
show quantity discountsEarthwool RS60 Universal Slabs are unfaced, rock mineral wool slabs, available in a range of densities from 33 to 200 kg/m3. The standard product is supplied unfaced, but slabs can also be manufactured with a factory applied foil or tissue facing and are also available with a water repellent additiv..
50mm Earthwool RS100 Universal Insulation Slab Knauf (pack of 6)
1200x600 - 4.32m2 show quantity discountsDelivery Time: 2 - 3 days
Guide Price: £35.43 (£42.52 inc VAT)
£8.20/m2 (£9.84/m2 inc VAT)
show quantity discounts50mm Earthwool Universal Slabs are unfaced, rock mineral wool slabs, available in a range of densities from 33 to 200 kg/m3. The standard product is supplied unfaced, but slabs can also be manufactured with a factory applied foil or tissue facing and are also available with a water repellent additiv..
50mm Earthwool Flexible Insulation Slab Knauf (pack of 12)
1200x600 - 8.64m2 show quantity discountsDelivery Time: 2 - 3 days
£45.31 (£54.37 inc VAT)
£5.24/m2 (£6.29/m2 inc VAT)
show quantity discounts50mm Earthwool Flexible is a non-combustible, inorganic rock mineral wool slab, used for thermal and acoustic insulation and specifically designed for installation by friction fitting. Earthwool Flexible is odourless, non-hygroscopic, rot proof, does not sustain vermin and will not encourage th..
25mm EcoTherm EcoVersal PIR Insulation Board
1200x2400mm - 2.88m2 show quantity discountsDelivery Time: 1 - 5 working days
£21.65 (£25.98 inc VAT)
£7.52/m2 (£9.02/m2 inc VAT)
show quantity discounts25mm Eco-Versal is a foil faced universal solution for insulating walls, floors, pitched roofs, dormer cheeks and ceilings. It is ideal for insulating timber frame walls and can also be used to insulate solid walls internally. EcoTherm Eco-Versal comprises a fibre free rigid polyisocyanurate (PIR) i..
60mm Rockwool Hardrock Multi-Fix (Dual Density ) Fleece Faced Board (pallet of 20)
1200x1000 - 24.00m2 Delivery Time: 8 - 12 weeks
Guide Price: £454.15 (£544.98 inc VAT)
£18.92/m2 (£22.70/m2 inc VAT)
60mm Rockwool Hardrock Multi-Fix Dual Density Fleece Faced Boards are manufactured from renewable volcanic stone which produces a non-combustible roofing insulation board. A uniquely versatile solution suitable for all roof covering types - torch, pour and roll, single ply, EPDM, liquid applied and ..
30mm Rockwool RW3 Slab (Prorox SL930) - pack of 15
1200x600mm - 10.8m2 Delivery Time: 1 - 2 days
Guide Price: £44.34 (£53.21 inc VAT)
£4.11/m2 (£4.93/m2 inc VAT)
30mm Rockwool RW3 Slab (Prorox SL 930) is a semi-rigid resin bonded slab, providing great thermal, acoustic and fire resistance, designed to be used in various applications in floors, walls and roofs, including special applications in industrial buildings for insulation of ships, offshore plat..
50mm Rockwool RW5 Universal Insulation Slab (Prorox SL960) - pack of 4
RW5 50mm - 2.88m2 show quantity discountsDelivery Time: 2 - 3 days
Guide Price: £31.69 (£38.03 inc VAT)
£11.00/m2 (£13.20/m2 inc VAT)
show quantity discounts50mm Rockwool RW5 (Prorox SL960) is a high quality resin bonded rigid slab for a wide range of thermal, acoustic and fire insulation requirements both within buildings and for industry. They are suitable for many applications including thermal insulation for floors, walls, roofs and boiler rooms. Th..
50mm Rockwool Flexi Insulation Slab - 1200mm x 600mm (pack of 12)
1200x600mm - 8.64m2 show quantity discountsDelivery Time: 1 - 2 days
£33.87 (£40.64 inc VAT)
£3.92/m2 (£4.70/m2 inc VAT)
show quantity discounts50mm x1200mm x 600mm Rockwool Flexi Insulation Slab is a unique semi-rigid thermal and acoustic insulation product made from volcanic rock. It has a flexible edge, specifically developed using patented technology for a fast and easy, perfect friction fit between timber and metal frame syst..
25mm Rockwool RWA45 Slab (Prorox SL920) - pack of 16
600x1200mm - 11.52m2 show quantity discountsDelivery Time: 2 - 3 days
Guide Price: £37.49 (£44.99 inc VAT)
£3.25/m2 (£3.90/m2 inc VAT)
show quantity discounts25mm Rockwool RWA45 is a high quality resin bonded flexible slab for a wide range of thermal, acoustic and fire insulation requirements both within buildings and for industry. They are suitable for many applications including thermal insulation for floors, walls, roofs and boiler rooms. The str..
50mm Rockwool Flexi Insulation Slab 1200 x 400mm (pack of 12)
1200x400mm - 5.76m2 show quantity discountsDelivery Time: 1 - 2 days
Guide Price: £34.77 (£41.72 inc VAT)
£6.04/m2 (£7.25/m2 inc VAT)
show quantity discounts50mm x1200mm x 400mm Rockwool Flexi Insulation Slab is a unique semi-rigid thermal and acoustic insulation product made from volcanic rock. It has a flexible edge, specifically developed using patented technology for a fast and easy, perfect friction fit between timber and metal frame syst..
25mm Yelofoam X2i Cellecta
2500x600mm - 1.5m2 Delivery Time: 2 - 4 days
25mm Cellecta Yelofoam is made of extruded polystyrene (XPS) foam blown with a mix of HFA & CO2 gases, containing a yellow pigment, flame retardant additive and nucleating agent. Cellecta insulation products are manufactured to the highest possible specification. Ex All products physical propert..
50mm Cellecta Hexatherm XROOF 300L Thermal Roof Insulation Board
600x1250mm - 0.75m2 Delivery Time: 2 - 4 days
50mm Cellecta Hexatherm XROOF 300L is an extruded polystyrene thermal insulation board designed specically for inverted roof applications where a high resistance to compression and water absorption is essential. XROOF roof insulation boards are ideal for a multitude of roofing requirements, inc..
50mm Cellecta Hexatherm XDRAiN Drainage Channel Inverted Roof Board
600x1250mm - 0.75m2 Delivery Time: 2 - 4 days
50mm Cellecta Hexatherm XDRAiN is a high performance extruded polystyrene inverted thermal roof boards, featuring integrated drainage channels on their underside, which speeds up the shedding of rainwater from the roof, eliminating the need for a separating drainage mat, making them ideal for green ..
56mm Cellecta Hexatherm XMD Vertical Up-Stand Roof Board
1200x2400mm - 2.88m2 Delivery Time: 2 - 4 days
56mm Cellecta Hexatherm XMD is a high performance extruded polystyrene thermal insulation board bonded to a 6mm thermal laminate facing, suitable for vertical upstands. It combines the benefits of high performance extruded polystyrene with a facing board to produce a composite thermal board to suit ..