120mm Insulation Boards (120mm PIR Insulation Board)
£52.99 £44.50 + VAT
- TypeGeneral purpose PIR board
- Size2400 x 1200 x 120mm
- Coverage2.88m² per board
- Thermal conductivity0.022 W/mK
General purpose PIR insulation board, 120mm thick, 2400mm x 1200mm (2.88m² per board). Foil faced both sides, 0.022 W/mK. Supplied as the best-stocked brand for your postcode: every brand we supply is made to this specification.
- Free delivery over £450.00 + VAT to most of the UK mainland
- Same specification whichever brand we send
- ASAP or a requested date, chosen at checkout. All deliveries signed for
120mm PIR insulation boards are the thick-board option for new-build floors and roofs where a single layer has to meet current Part L U-values on its own. One 120mm board saves a second layer, which means fewer joints to tape, faster fitting and less wastage on site.
What you get
Every 120mm board we supply is a general purpose, foil-faced PIR insulation board, 2400mm x 1200mm, covering 2.88m² per board. Thermal conductivity is 0.022 W/mK, which gives an R-value of around 5.45 m²K/W at 120mm. All of the manufacturers we work with make their general purpose board to this same specification, so the board you receive is simply the best-stocked brand for your postcode.
Where 120mm general purpose PIR boards are used
- New-build ground floors under screed or chipboard
- Warm flat roofs and terraces over the deck
- Pitched roofs over the rafters as a sarking layer
- Loft conversions and room-in-roof build-ups
- Extensions that have to meet Part L in one layer
Ordering tip
Thick boards are heavier per sheet, so allow enough people on site to offload the pallet from the lorry when it arrives.
120mm general purpose PIR board specification
Every brand we supply makes its general purpose board to this specification. The name on the foil may differ; the performance does not.
| Product type | General purpose PIR insulation board |
|---|---|
| Thickness | 120mm |
| Board size | 2400mm x 1200mm |
| Coverage | 2.88m² per board |
| Thermal conductivity | 0.022 W/mK |
| Thermal resistance (R-value) | 5.45 m²K/W |
| Facings | Low emissivity aluminium foil, both sides |
| Core | Rigid PIR foam, approx. 31 kg/m³ |
| Edge profile | Square edge |
| Weight | 4.93 kg/m² (about 14.2 kg per board) |
| Reaction to fire | Euroclass F (board only) |
| Ozone depletion | Zero ODP, low GWP blowing agent |
| Brands supplied | Kingspan, Celotex, Soprema, Unilin, IKO, Ecotherm, Mannok, Recticel (all made to this specification) |
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Questions about ordering
Straight answers on brands, delivery and quantities. Anything else, ask us.
Which brand will I receive?
One of the brands shown on our site, currently Kingspan, Celotex, Soprema, Unilin, IKO, Ecotherm, Mannok or Recticel. We only sell general purpose PIR boards and every manufacturer we work with makes theirs to the same specification: 2400 x 1200, foil faced both sides, 0.022 W/mK. We send whichever brand is best stocked for your postcode, which is how we offer lower prices and faster delivery. You cannot choose a specific brand.
Are the boards new?
Yes. Every board we sell is brand new, factory fresh stock from the manufacturer, never seconds, surplus or reclaimed. It arrives in the manufacturer's packaging on a pallet.
What is this board used for?
General purpose PIR boards are used in floors (under screed, between joists, over beam and block), walls (timber frame, internal linings) and roofs (between or over rafters, warm flat roofs). The thickness you need depends on the target U-value and the build-up; the specification tab gives the R-value for this thickness.
Do I need to tape the joints?
For a warm roof or where the foil is acting as a vapour control layer, yes: tape the joints with a foil tape. For floors under screed, lap the joints tightly and use a polythene separating layer over the boards.
Are the boards really the same specification?
Yes. Thermal conductivity, thickness, board size and facings are identical across the brands we supply, so the U-value you achieve is the same whichever one arrives. The only difference is the name printed on the foil.
How quickly will my order arrive?
Order before 2:30pm on a working day and the earliest delivery is 3 working days, on average. Orders after 2:30pm, or at the weekend, take 4 working days on average. Dates can vary by area and availability, and we confirm your date by email once the order is booked. At checkout you can choose ASAP or request a later date.
How much does delivery cost?
Delivery is free on orders over £450.00 + VAT to most of the UK mainland. Smaller orders pay a flat delivery charge that is shown at checkout once you enter your postcode. A few postcode areas have their own rates, and we cannot deliver to Northern Ireland, the islands or the far north of Scotland. Full details are on the delivery page.
How many boards do I need?
Each board covers 2.88m². Divide your area by 2.88 and round up, allowing a little extra for cuts. The order form calculator does this for you.
Can I mix thicknesses in one order?
Yes. Use the order form to add several thicknesses at once, or add boards from the individual product pages. Everything ships together.
All thicknesses
Same general purpose specification in every size. Prices per 2400 x 1200 board, ex VAT.
20mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
25mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
30mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
40mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
50mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
60mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
70mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
75mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
80mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
90mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
100mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
110mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
120mmViewing- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
130mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
140mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
150mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
165mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity
200mm- Brand new general purpose PIR, 2400 x 1200
- 2.88m² per board
- 0.022 W/mK thermal conductivity