Insulation Boards

What are Insulation Boards?

Insulation boards, otherwise known as foam board insulation, are rigid panels of insulation that are made from either polystyrene or polyisocyanurate. An insulation board is generally faced with different materials, such as aluminium foil or integral vapour barriers to prevent water from passing through; this will help to eliminate the chances of moisture buildup, in turn, reducing mould growth.

In short, insulation boards are purposed to insulate any exposed cavity in your home from the top to the bottom, even your walls.

We suggest seeking professional advice before installing insulation boards to get a proper gauge of what equipment and other building materials might be needed.

Types of Insulation Boards

There are five ruling types of insulation boards on the market; PIR insulation boards, Phenolic insulation boards, XPS insulation boards, EPS insulation boards and Cavity Wall insulation boards. At their (rigid foam) core, insulation boards are specifically designed to reduce undesirable heat loss, thus bringing heating bills down.

Insulation board (otherwise known as an insulation sheet) is easy to cut and can be used in a wide variety of applications, such as in a pitched roof, an internal wall, or under a loft board. We stock PIR insulation foam board from industry-leading brands like EcoTherm, Celotex and Recticel in different types of thicknesses that range from 20mm to 150mm, with the Celotex 100mm thickness being our top seller. If it's thermal and acoustic insulation you're after, then insulation slabs are your best bet.

PIR Insulation Boards

Polyisocyanurate (PIR) insulation board is one of the most popular thermal insulation board choices for construction projects. Very nearly as thermally efficient as phenolic boards, PIR insulation board is made from polyisocyanurate, a rigid material, making the boards durable and sturdy.

Not only do the boards offer excellent thermal performance, but they are also moisture resistant thanks to their closed-cell structure. This excellent drying potential sets you up for years of consistent thermal performance - promising maximum protection for the lifetime of your build. Additionally, the boards showcase low-emissivity foil facings on either side which increase their thermal performance in sealed air cavities; producing a superior U Value to other insulation solutions on the market.

Phenolic Insulation Boards

As with PIR boards, phenolic insulation boards also have a closed-cell structure. However, most phenolic boards boast an impressive lambda value of just 0.018 W/mK (with the very highest value coming in at 0.023 W/m.K); making them the most thermally efficient cavity insulation solution on the market.

Phenolic board has a slightly higher R-value (the higher the better) and a slightly thinner profile than PIR boards. The boards are comprised of a fibre-free rigid thermoset phenolic core flanked by either a layer of low emissivity composite foil on either side or glass tissue based facing.

They are also manufactured in a super environmentally friendly process, using a blowing agent with zero Ozone Depletion Potential and a low Global Warming Potential; one less worry for you and the environment.

XPS Insulation Boards

Extruded polystyrene insulation (XPS) is manufactured using a process of extrusion. This process results in a closed-cell structure that boasts smooth, dense skin on both faces. The closed-cell structure of extruded polystyrene (XPS) prevents water penetration, thus providing long-term strength and durability.

Furthermore, its dense composition gives it greater compressive strength than other types of insulation. This makes XPS insulation a cracking choice for floor insulation as well as ceiling and flat roof insulation.

EPS Insulation Boards

This is the most basic insulation board as it offers the lowest R-value (meaning it has the least effective thermal performance). Unlike XPS insulation, EPS insulation features small voids between the foam beads, where they haven’t completely fused together.

Whilst it has a closed-cell structure, EPS is not a closed-cell insulation board, meaning it allows water vapour/moisture to penetrate over time. EPS board's strength lies in its strength (literally). Its most common applications are below a concrete slab with concrete poured on top or also being used as a walkway board with chipboard laminated to the board. Because of its lack of thermal performance, it is one of the cheapest boards you can get your hands on. 

Cavity Wall Insulation Boards

Cavity wall insulation boards are designed to fill the space and provide extra insulation between two external walls. Cavity boards trap heat inside your home by inhibiting heat transfer; meaning your comfort goes up and your energy bills go down. An insulation board for cavity walls can have a thermal conductivity value as low as 0.018 W/mK.

Celotex CW4000 is the leading brand in the market for PIR cavity wall insulation. This rigid polyisocyanurate (PIR) insulation solution is manufactured specifically for use in partial fill cavity walls. Comprised of a PIR core sandwiched between low emissivity foil facings on both sides, these boards have a thermal conductivity of just 0.022 W/mK; making them a far more effective thermal cavity solution than either rock or glass mineral wool insulation.