Where to buy PIR insulation?

You can buy PIR board insulation online from specialist insulation stores such as Insulation Wholesale. As a leading PIR insulation supplier, we stock a full range of panels for walls, floors, roofs, and lofts – from foil-faced wall panels to roof-ready boards and heavy-duty floor insulation. If you are budgeting for a project, our team can provide quick, accurate quotes so you know the current PIR insulation prices before you order.

How to cut PIR insulation?

Mark your cut line. Use a straightedge or long level. If your line is crooked, your cut will be too. Score the foil first. Take a sharp utility knife and lightly score along your line. This does not slice the board – it just breaks the foil, leaving a neat edge. Deepen the cut. Run your knife over the same line three or four times. You will feel it sink deeper each pass. For thinner boards (25–50mm), you can usually cut through the material with the knife alone. Snap the board. For thicker boards (75–150mm), once the knife has cut through the foil and a bit into the foam, tilt the board over an edge or your knee and snap it along the scored part. The core breaks cleanly. Trim the back. After snapping, the face will be clean-cut, and the back partially torn. Score the back foil with your knife and slice off the remaining foam. Optional: use a handsaw. If you prefer one tool start to finish, a fine-tooth handsaw works well. It is slightly messier but great for deep cuts or angled pieces.

How to install PIR insulation?

1.Between Studs, Joists, or Rafters This is the classic “cut to fit and friction-fix” method. Cut each board 3–5 mm wider than the gap. Fit it into the space so it grips the sides. That slight pressure keeps it snug. Make sure the face of the board sits flush with the timber so your plasterboard or internal lining lands cleanly. Tape the foil joints to get a tighter vapour barrier. PIR is rigid enough to bridge the gap, and the foil face helps stop air movement. Always follow system-specific guidance for vapour control and ventilation requirements. 2.Over Joists, Rafters, or Stud Walls (Continuous Layer) This provides the best thermal performance by eliminating cold spots. Fix the boards directly over the timber using insulation fixings or long screws with washers. Stagger the joints so no straight lines run through the insulation. Tape all joints with foil tape to seal the layer. Fit your plasterboard or deck on top using long screws that reach the timber below. The full sheet covers every timber, giving a more even thermal layer. 3.Solid Masonry Walls (Internal Facing) This is the "insulated lining board" approach. Dot-and-dab adhesive or mechanical fixings can be used, depending on the spec. Boards must sit flat with no steps between them. Tape joints, then add plasterboard over the top, or use insulated plasterboard that includes PIR. It creates a warm internal surface and stops heat from bleeding into the cold wall. 4.Floors Most PIR in floors is installed under the screed or under a chipboard deck. Lay a DPM if needed. Put PIR boards tightly together with staggered joints. Tape where required, then add your screed or deck on top. The rigid foam handles the load once it is supported by the layers above. 5.Flat Roofs Both warm-roof and inverted-roof setups commonly use PIR. Lay the boards over the roof deck. Stagger joints. Mechanically fix or bond, depending on the roof system. Add the waterproofing membrane over the top.

Can PIR insulation get wet?

PIR itself does not soak up water easily. So if the board gets a light splash or short-term exposure, it will not suddenly fall apart or lose its thermal performance. But it is not designed to stay wet because this can affect long-term stability. Long-term immersion or condensation behind the board can degrade facers or structure.

Can you use PIR insulation in loft?

Yes, PIR insulation works very well in a loft. Between Rafters Fit PIR panels snugly between the rafters, leaving the required ventilation gap above – usually 25–50mm, depending on the roof. Seal small gaps with foam or tape to prevent cold bridges. Under Rafters (to boost U-value) A continuous layer of foil-faced PIR is fixed across the underside of the rafters. This adds thermal performance, covers up imperfect cuts between rafters, and the foil layer acts as a vapour-control layer once joints are taped. Over Rafters (warm roof method) If you are re-roofing, PIR slabs can be laid on top of the rafters before the breather membrane and tiles go on. This gives you a full warm roof with minimal thermal bridging – the most efficient loft system, but only practical during roof replacement.

PIR Polyisocyanurate Insulation At Low Wholesale Prices

15mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 160 (460.80m2)

15mm Unilin Thin-R PIR insulation is a foil faced, high-performance insulation solution that offers exceptional thermal efficiency and durability. This polyisocyanurate insulation board, formerly known as Xtratherm, is ideal for a range of applications, such as floors, pitched roofs, and walls.

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165mm Celotex XR4165 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 12

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165mm Celotex XR4165 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 12

165mm XR4165 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£1,020.95£1,225.14 Ex VATInc VAT
£29.54£35.45 Per M2 Add to cart

165mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 14 (40.32m2)

165mm Unilin Thin-R PIR insulation is a foil faced, high-performance insulation solution that offers exceptional thermal efficiency and durability. This polyisocyanurate insulation board, formerly known as Xtratherm, is ideal for a range of applications, such as floors, pitched roofs, and walls.

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200mm Celotex XR4200 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 12

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200mm Celotex XR4200 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 12

200mm XR4200 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£1,377.04£1,652.45 Ex VATInc VAT
£39.84£47.81 Per M2 Add to cart

20mm Kingspan OPTIM-R Roofing Insulation Board

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20mm Kingspan OPTIM-R Roofing Insulation Board

20mm Kingspan OPTIM-R Roofing Insulation Panels achieve a declared thermal conductivity of 0.007 W/m∙K.

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20mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

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20mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

20mm Mannok PIR Insulation Board is an excellent choice for anyone looking for a high-performance insulation solution that provides superior thermal efficiency. It is ideal for use in any construction project, such as commercial and residential, in wall applications as well as roofing and flooring applications.

POA Get a quote

20mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 120 (345.60m2)

20mm Unilin Thin-R PIR insulation is a foil faced, high-performance insulation solution that offers exceptional thermal efficiency and durability. This polyisocyanurate insulation board, formerly known as Xtratherm, is ideal for a range of applications, such as floors, pitched roofs, and walls.

POA Get a quote

25mm Celotex PIR Insulated Plasterboard 1200mm x 2400mm + 12.5mm P/B 2.88m2

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25mm Celotex PIR Insulated Plasterboard 1200mm x 2400mm + 12.5mm P/B 2.88m2

25mm + 12.5mm Celotex PL4025 PIR Insulated Plasterboard is it is suitable for use in roof and internal wall lining applications. Celotex Insulated Plasterboard is a high performance, easy to install PIR insulation board with a paper facing, laminated to a piece of 12.5mm tapered edge plasterboard.

£36.53£43.84 Ex VATInc VAT
£12.68£15.22 Per M2 Add to cart

25mm Celotex TB4025 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

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25mm Celotex TB4025 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

25mm Celotex TB4025 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£15.35£18.42 Ex VATInc VAT
£5.33£6.40 Per M2 Add to cart

25mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8' x 4') 2.88m2

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25mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

25mm Ecotherm Eco-Versal is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Ecotherm Eco-Versal is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£15.77£18.92 Ex VATInc VAT
£5.48£6.58 Per M2 Add to cart

25mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

IKO-Enotherm-PIR-Insulation-Board-Pitched-Roof

IKO-PIR-Insulation-Board-Therm-Floor-Application

25mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

25mm IKO Enertherm ALU PIR (polyisocyanurate) insulation is a top-quality insulation board featuring a rigid PIR foam core and reflective aluminium foil facings. It delivers outstanding thermal performance and moisture resistance, making it suitable for various installations and an ideal choice for different energy-efficient projects.

POA Get a quote

25mm Kingspan OPTIM-R Flooring Insulation Board

25mm Kingspan OPTIM-R Flooring Insulation Board

25mm Kingspan OPTIM-R Flooring Insulation Panels achieve a declared thermal conductivity of 0.007 W/m∙K.

POA Get a quote

25mm Kingspan OPTIM-R Roofing Insulation Board

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25mm Kingspan OPTIM-R Roofing Insulation Board

25mm Kingspan OPTIM-R Roofing Insulation Panels achieve a declared thermal conductivity of 0.007 W/m∙K.

POA Get a quote

25mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

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25mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

25mm Mannok PIR Insulation Board is an excellent choice for anyone looking for a high-performance insulation solution that provides superior thermal efficiency. It is ideal for use in any construction project, such as commercial and residential, in wall applications as well as roofing and flooring applications.

POA Get a quote

25mm Recticel Eurothane Eurodeck Insulation Board 2400mm x 1200mm Pack of 12 (34.56m2)

25mm Recticel Eurothane Eurodeck Insulation Board 2400mm x 1200mm Pack of 12 (34.56m2)

25mm Eurothane^® Eurodeck is compatible with mechanically fixed single-ply systems, benefiting from high compressive strength and excellent dimensional stability that ensures the flat surface finish required for optimum performance in new build and refurbishment projects. It is faced on both sides with a multi-layer coated aluminum foil.

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25mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

25mm Recticel Eurothane GP is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Recticel is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£16.10£19.32 Ex VATInc VAT
£5.59£6.71 Per M2 Add to cart

25mm Recticel Powerdeck F Flat Roof Insulation Board 1200mm x 600mm Pack of 20 (14.40m2)

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25mm Recticel Powerdeck F Flat Roof Insulation Board 1200mm x 600mm Pack of 20 (14.40m2)

25mm Powerdeck F flat roof insulation board is compatible with multiple waterproofing systems, benefiting from high compressive strength and excellent dimensional stability. Both sides of Powerdeck F are faced with a mineral coated glass fleece.

£149.00£178.80 Ex VATInc VAT
£10.35£12.42 Per M2 Add to cart

25mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 96 (276.48m2)

25mm Unilin Thin-R PIR insulation is a foil faced, high-performance insulation solution that offers exceptional thermal efficiency and durability. This polyisocyanurate insulation board, formerly known as Xtratherm, is ideal for a range of applications, such as floors, pitched roofs, and walls.

POA Get a quote

30mm Celotex TB4030 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

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30mm Celotex TB4030 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

30mm Celotex TB4030 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£18.99£22.79 Ex VATInc VAT
£6.59£7.91 Per M2 Add to cart

30mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8' x 4') 2.88m2

30mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

30mm Ecotherm Eco-Versal is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Ecotherm Eco-Versal is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£19.51£23.41 Ex VATInc VAT
£6.77£8.12 Per M2 Add to cart

30mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

30mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

30mm IKO Enertherm ALU PIR (polyisocyanurate) insulation is a top-quality insulation board featuring a rigid PIR foam core and reflective aluminium foil facings. It delivers outstanding thermal performance and moisture resistance, making it suitable for various installations and an ideal choice for different energy-efficient projects.

POA Get a quote

30mm Kingspan OPTIM-R Roofing Insulation Board

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30mm Kingspan OPTIM-R Roofing Insulation Board

30mm Kingspan OPTIM-R Roofing Insulation Panels achieve a declared thermal conductivity of 0.007 W/m∙K.

POA Get a quote

30mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

There are 10 more images

30mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

30mm Mannok PIR Insulation Board is an excellent choice for anyone looking for a high-performance insulation solution that provides superior thermal efficiency. It is ideal for use in any construction project, such as commercial and residential, in wall applications as well as roofing and flooring applications.

POA Get a quote

30mm Recticel Eurothane Eurodeck Insulation Board 2400mm x 1200mm Pack of 10 (28.80m2)

30mm Recticel Eurothane Eurodeck Insulation Board 2400mm x 1200mm Pack of 10 (28.80m2)

30mm Eurothane^® Eurodeck is compatible with mechanically fixed single-ply systems, benefiting from high compressive strength and excellent dimensional stability that ensures the flat surface finish required for optimum performance in new build and refurbishment projects. It is faced on both sides with a multi-layer coated aluminum foil.

POA Get a quote

30mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

30mm Recticel Eurothane GP is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Recticel is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£19.44£23.33 Ex VATInc VAT
£6.75£8.10 Per M2 Add to cart

30mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 80 (230.40m2)

30mm Unilin Thin-R PIR insulation is a foil faced, high-performance insulation solution that offers exceptional thermal efficiency and durability. This polyisocyanurate insulation board, formerly known as Xtratherm, is ideal for a range of applications, such as floors, pitched roofs, and walls.

POA Get a quote

40mm Celotex PIR Insulated Plasterboard 1200mm x 2400mm + 12.5mm P/B 2.88m2

40mm Celotex PIR Insulated Plasterboard 1200mm x 2400mm + 12.5mm P/B 2.88m2

40mm Celotex PL4040 PIR Insulated Plasterboard is it is suitable for use in roof and internal wall lining applications. Celotex Insulated Plasterboard is a high performance, easy to install PIR insulation board with a paper facing, laminated to a piece of 12.5mm tapered edge plasterboard.

£45.45£54.54 Ex VATInc VAT
£15.78£18.94 Per M2 Add to cart

40mm Celotex TB4040 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

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40mm Celotex TB4040 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

40mm Celotex TB4040 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£22.13£26.56 Ex VATInc VAT
£7.68£9.22 Per M2 Add to cart

40mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8' x 4') 2.88m2

40mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

40mm Ecotherm Eco-Versal is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Ecotherm Eco-Versal is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£22.75£27.30 Ex VATInc VAT
£7.90£9.48 Per M2 Add to cart

40mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

40mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

40mm IKO Enertherm ALU PIR (polyisocyanurate) insulation is a top-quality insulation board featuring a rigid PIR foam core and reflective aluminium foil facings. It delivers outstanding thermal performance and moisture resistance, making it suitable for various installations and an ideal choice for different energy-efficient projects.

POA Get a quote