PIR Insulation

PIR Insulation: What It Is & When It’s the Right Choice

When It’s the Right Choice

• You need high insulation performance without adding significant thickness to the build-up.
• You’re insulating floors, walls, roofs, or lofts and want a rigid, easy-to-fit board.
• You want a clean, flat finish that is easy to cut and install.
• You are upgrading a space where minimal thickness is essential.
• You’re matching a specific build-up and prefer to shop by thickness to suit the job.

Why Choose PIR Insulation Boards

• PIR insulation improves thermal performance without creating a bulky build-up, making it useful when space is limited.
• The rigid board format gives a clean, consistent insulation layer that’s easy to measure, cut, and fit neatly.
• A PIR insulation board is commonly used in floors, walls, roofs, and lofts across standard building and renovation jobs.
• Foil-faced options are compatible with standard construction build-ups and help achieve a neat finish when properly installed.
• A wide choice of thicknesses makes it easier to match the insulation to your build-up and project requirements.
• For both trade and DIY applications, rigid PIR insulation enables straightforward installation and consistent results on site.

Explore our full Insulation Boards range to compare different board types and choose the right option for your build-up.

PIR Insulation Thickness Guide: Shop by Thickness

• 25mm PIR insulation - Best for tight tolerances and small upgrades: service voids, lining build-ups, and situations where you need a little extra performance without changing levels or details too much.
• 50mm PIR insulation - A common “all-rounder” for renovation work where you want a noticeable improvement but still need to keep the build-up sensible, especially on walls and certain floor build-ups.
• 75mm PIR insulation: Used when higher performance is needed and additional depth is available, suitable for floors and roofs requiring more than a basic upgrade.
• 100mm PIR insulation: A popular choice for floors and roofs where sufficient depth is available and a robust insulation layer is desired without complicating the build.
• 150mm PIR insulation - Used when you’ve got the space, and you’re targeting high insulation levels, commonly in roof and floor constructions where depth is less of a constraint and performance is the priority.

Where PIR Insulation Works Best

• Floors: PIR boards are commonly used in both solid and suspended floor build-ups to provide a uniform, flat layer that reduces heat loss. They are practical for installations around joists, services, or tight tolerances while maintaining a neat finish.
• Roofs - PIR roof insulation is widely used in pitched and flat roof build-ups, particularly when effective insulation within a controlled depth is required. The board format makes it easier to keep the layer consistent across the area, which helps achieve a clean, reliable installation.
• Walls - As PIR wall insulation, PIR boards suit many common wall build-ups where you want a straight, even layer behind a lining system or within a renovation upgrade. It’s often selected when you’re trying to improve warmth while keeping the room footprint and build-up as manageable as possible.
• Lofts - For PIR loft insulation, PIR is a good fit for loft upgrades and conversions where space can be limited, and access isn’t always perfect. The rigid board format helps you create a consistent insulation layer without relying on compressible materials, which can be useful when you want a neat, controlled result.