Everything You Need to Know About PIR Insulation

Polyisocyanurate boards, known as PIR insulation boards, are rigid insulation boards used throughout construction. They bring several clear advantages over previously used polyurethane (PUR) boards. We’ve created this guide to PIR Insulation to help our customers gain an understanding of its benefits and to talk you through the wide range of products we sell through our website.

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What is PIR Insulation?

PIR, which stands for Polyisocyanurate, is made of a thermoset plastic that is produced by blowing agents as foam insulation, before being formed into solid boards. Though PIR and PUR are produced from similar materials, the chemical structure of PIR is actually very different. PIR insulation boards have become a favourite within the industry for a few clear reasons. They offer a strong level of thermal performance, avoiding the passage of heat. They can also come faced with foil to inhibit the passage of moisture. Compared to other materials you can get a strong performance from a thinner PIR insulation board, leaving you with more floor space when installed internally. 

PIR insulation boards also offer great longevity, retaining their shape and strength over time. Depending on the manufacturer they can be built with fire-resistant properties. They are also easy to work with and install, with builders simply cutting boards to size.

What PIR Insulation Products Are Available?

Solid PIR insulation boards can be used throughout a building, but there are also PIR insulation products designed to work in specific areas. Foil-faced PIR insulation boards can be used to eliminate thermal bridges within cavities or as part of exterior walls. PIR insulation bonded plasterboards are also available, offering a great option for internal wall insulation. PIR-insulated plywood offers a high level of thermal insulation within flat roofs. There are also PIR Insulation boards specially intended for cavity wall insulation, though these will need to be installed during the building process.

Where Can PIR Insulation be Used?

Regular PIR insulation boards can be used throughout a building. They can be used in a pitched roof, installed between the joists. They can be installed within a warm flat roof, offering a sturdy and effective insulation layer. They can be installed as timber framing wall insulation, cut to size and fitted between studs. They can also be used between ceiling joists and floor joists. PIR insulation boards work for most general insulation applications, offering a strong level of thermal support and a quick and easy installation. 

As stated above there are also specialist PIR Insulation products that can be used as cavity wall insulation, flat roof insulation, and as part of dry lining. PIR insulation can be used throughout a building, offering strong thermal support.

Is PIR Insulation Safe?

PIR insulation is used throughout building projects in the UK. Each product will come with its own ratings for things like fire safety. Whenever conducting a building project you should carefully check that every product you use has an appropriate safety rating. Within the UK there are strict building regulations that everyone must adhere to.

Can PIR Insulation Get Wet?

PIR Insulation should be kept away from water, unless specifically designed for moisture resistance, with foil facings. If boards do get wet, they should be left to thoroughly dry out before being installed within a building. Water absorption in solid PIR insulation should be minimal, especially compared to other insulation options like mineral wool.

Is PIR Insulation Flammable?

PIR Insulation is not typically flammable, though you should always check the manufacturer's information to see its fire rating. However. PIR insulation can release toxic smoke when burnt, regardless of it they are flammable, which should be taken into account within building projects. Fire safety should be of the highest priority in any building project, and you should make sure the fire performance of all materials is adequate and that combustible materials are avoided.

Can Electric Cables Touch PIR Insulation?

As long as the electric cables are insulated then there should be no issues with them directly touching PIR insulation boards.

What PIR Insulation Boards do we sell?

We stock a wide range of PIR insulation boards for sale through our website. These boards are from industry-recognised brands and can be used throughout both new builds and refurbishment projects. Here are some of our range:

• Ecotherm Eco-Versal PIR Insulation Boards: A general-purpose insulation board with an aluminium foil facing on both sides. Manufactured in thicknesses from 25mm to 150mm, these boards can be used in both new builds and renovation projects. They can be used in pitch roofs, flat roofs, timber stud wall insulation, floors, and ceilings. They offer excellent thermal performance, are more solid than traditional insulation, and are easy to cut and install for efficient insulation.
• Xtratherm Thin-R PIR Insulation Boards: Available in thicknesses from 30mm to 150mm, these general-purpose insulation boards are foil-faced for vapour control and to minimise heat loss. The Thin-R can be used in pitched roofs, floors, stud walls, ceilings and lofts. They are lightweight, easy to install, and offer great thermal performance.
• Warmline PIR Insulated Plasterboard: An insulated plasterboard available in widths from 29.5mm to 89.5mm, this can be used to increase the thermal efficiency of walls and ceilings. Made of PIR foam bonded to plasterboard, it can be used for both insulation and dry lining, attached either through a stud wall or through a dot and dab. Can be used within new builds and as easy refurbishment.
• British Gypsum Gyproc ThermaLine PIR Insulated Plasterboards: Sold in thicknesses from 38mm to 93mm, this insulated plasterboard offers a strong level of thermal performance. It incorporates a Gyproc WallBoard which offers fire retardant and acoustic performance. Whether in a new build or a refurbishment, these insulated plasterboards can preserve heat in walls or ceilings.
• Celotex Thermal Laminate Insulated Plasterboard: A Celotex brand PIR insulated plasterboard sold in thicknesses from 27.5mm to 77.5mm. This will offer strong thermal insulation when attached to a wall or ceiling.
• Warmline PIR Insulated Plywood: Sold in thicknesses from 76mm to 159mm, these high-performance insulated decking boards can be used in flat roofs, offering strong thermal decking. They allow insulation and decking in one step and can be installed in new builds or as part of a refurbishment.

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