Kingspan PIR boards

Who makes Kingspan PIR insulation boards

Kingspan is an Irish company. The group was founded in 1965 by Eugene Murtagh in Kingscourt, County Cavan, and its headquarters remain in Kingscourt today. Kingspan Group plc has its primary listing on Euronext Dublin, trades in more than 80 countries and employs around 27,000 people. Insulation is one of its largest divisions and the one that produces the Kingspan PIR insulation boards sold through merchants and online suppliers in the UK.

The UK business, Kingspan Insulation Ltd, is based at Pembridge near Leominster in Herefordshire, which is both its head office and its principal factory. It also manufactures at a second site near Selby in North Yorkshire, and both plants hold ISO 9001 quality management and ISO 14001 environmental management certification. Kingspan Insulation was an early holder of BES 6001 responsible sourcing certification for insulation made at its British factories, and its PIR boards are covered by British Board of Agrement certificates for the roof, wall and floor applications they are designed for, which is the paperwork a building control officer or warranty provider expects to see.

The general purpose Kingspan PIR board

The board PIR Boards sells is the general purpose rigid PIR insulation board, 2400 x 1200mm, which covers 2.88 square metres per sheet. It has a low emissivity aluminium foil facing bonded to both sides of a closed-cell polyisocyanurate foam core. The foil protects the core and acts as a vapour control layer once the joints are taped.

The declared thermal conductivity is 0.022 W/mK across every thickness we stock, from 20mm up to 200mm. That figure is the reason PIR is the default choice when depth is limited. Mineral wool at roughly 0.035 to 0.044 W/mK needs around 60 to 100 percent more depth to reach the same U-value, so a 100mm Kingspan PIR board does a job that would otherwise take 160mm or more of fibre.

Where Kingspan PIR insulation boards are used

Kingspan PIR insulation boards are a general purpose product, which means the same board is used in most parts of the building envelope. In pitched roofs the thicker sizes, typically 100mm to 150mm, go between the rafters, with a further 25mm to 50mm layer fixed under the rafters to break the cold bridge through the timber. In flat roofs the board sits on the deck in a warm roof build-up, usually 120mm to 150mm, below the waterproofing.

On floors a 100mm or 150mm Kingspan PIR board laid over the slab or between joists, with the joints taped and the edges upstanding, is the standard detail for new ground floors, extensions and garden rooms. In timber frame walls 50mm to 100mm sits between the studs, and in masonry walls the board is used as internal wall insulation behind a service void or plasterboard. The thin boards, 20mm, 25mm and 30mm, are used for dormer cheeks, window reveals, thermal breaks around steels and as an under-rafter layer in loft conversions where every millimetre of headroom counts.

Thickness is the only decision you need to make on PIR Boards. As a quick guide: 25mm to 50mm for lining, upgrades and cold bridging; 75mm to 100mm for walls and the first layer in roofs; 100mm to 150mm for floors and flat roofs; 150mm to 200mm where a single layer has to reach a demanding U-value on its own.

How PIR Boards supplies Kingspan PIR insulation boards

PIR Boards sells by thickness rather than by brand. Kingspan is one of the brands we supply, alongside other manufacturers whose general purpose PIR board is made to the same specification: 2400 x 1200mm, foil faced on both sides, 0.022 W/mK. When you order 100mm boards, we dispatch the brand that is best stocked at the depot serving your postcode on the day. That may be Kingspan, and it may be another brand with identical declared performance.

Merchants switch between manufacturers constantly, because a 100mm board at 0.022 W/mK gives exactly the same U-value whichever factory produced it. By pooling supply across manufacturers, PIR Boards keeps trade prices low, avoids the long waits that follow when one factory's line is busy, and can hold its delivery promise on even the less common thicknesses. Your U-value calculation, your building control submission and your installation detail are unaffected. The only thing that changes is the print on the foil.

If a specifier has named Kingspan PIR insulation boards on a drawing, they almost always mean the general purpose board at this specification, and a board of equal performance from another manufacturer is normally accepted as an equivalent. If your contract genuinely requires one named brand, contact us before ordering and we will tell you what we can do rather than promise something we cannot guarantee.

Working out how many PIR boards you need

Each 2400 x 1200 board covers 2.88 square metres. Measure the area to be insulated, divide by 2.88 and round up, then add about 10 percent for cuts and offcuts. For a 6m x 4m extension floor that is 24 square metres, which is 8.33 boards, rounded up to 9, plus 10 percent makes 10 boards. Allow 15 percent for between-rafter work, where each board is ripped into strips and the rips rarely divide evenly.

For a two-layer roof, calculate each layer separately. The under-rafter layer is a continuous sheet with little waste, while the between-rafter layer follows the rule above. Keep the offcuts. Thin strips of Kingspan PIR board are useful for packing out, dormer cheeks and thermal breaks around steels and lintels.

Cutting, fitting and taping

PIR board is one of the easier insulation materials to work with. Thicknesses up to about 50mm cut cleanly with a sharp knife or a fine-toothed insulation saw, and thicker boards with a handsaw or a circular saw with a fine blade. Mark both faces, cut square against a clamped straight edge and keep the dust down with a mask and a sheet underneath.

Between rafters or studs the board should be cut a few millimetres oversize so it friction fits without gaps, and any gaps that remain are filled with expanding PU foam and trimmed flush when cured. Under rafters and over slabs the boards are laid in a brick bond pattern so joints do not line up in both directions.

Tape every joint. A foil tape at least 75mm wide, pressed firmly over clean dry joints, turns the foil facing into a continuous vapour control layer and stops warm air carrying moisture into the roof or wall. On the warm side of the construction this is what the condensation guidance in the Building Regulations expects, and it is the step most often skipped.

Why 0.022 W/mK matters for your U-value

Thermal conductivity, the lambda value, tells you how much heat passes through one metre of material for each degree of temperature difference. The lower the number, the better the insulation. A U-value calculation divides each layer's thickness by its conductivity to get its thermal resistance, adds the resistances of every layer in the construction, and inverts the total. A 100mm board at 0.022 W/mK contributes a resistance of about 4.5 m2K/W; the same board at 0.025 W/mK would contribute only 4.0, which can be the difference between passing and failing a target U-value.

Because every brand PIR Boards supplies, Kingspan included, is declared at 0.022 W/mK, the U-value you calculate for a given thickness holds whichever board arrives. That consistency is the whole point of specifying by performance rather than by name, and it is why building control officers accept it.

Storage, handling and delivery

Store PIR insulation boards flat, off the ground and under cover. Boards left on edge or on uneven bearers will bow, and once bowed they do not sit flat against a deck or slab. Keep the polythene wrapping on until the boards are needed and protect open packs from rain. PIR does not rot and is not damaged by brief wetting, but water trapped between boards can take weeks to dry and reduces performance until it does.

PIR Boards delivers Kingspan PIR insulation boards and every other brand we supply across the UK mainland. Order before 2:30pm on a working day for delivery in 3 working days on average. Dates can vary by area and availability, and we will tell you if your postcode or thickness needs longer. Delivery is free on UK mainland orders over £450 + VAT. Make sure there is access for a lorry and someone to check the pack count and thickness before the driver leaves.