Kingspan Kooltherm

Kingspan Kooltherm is a range of fibre-free rigid thermoset phenolic insulation boards, widely regarded as one of the highest-performing rigid insulation options available in the UK market. With lambda values as low as 0.018 W/mK on selected boards, Kooltherm delivers exceptional thermal performance in thinner profiles than most alternative board types, making it a preferred specification wherever space is limited and U-value targets are demanding. All boards are CFC and HCFC-free with a low global warming potential, and the range spans application-specific products covering floors, walls, roofs, soffits and framing systems.

Kooltherm Board Types

Each board in the Kooltherm range is engineered to the specific performance and installation requirements of its intended application, with distinct facings, thermal conductivity values and compressive strengths suited to the demands of each build element.

K103 Floorboard

The Kooltherm K103 is a phenolic floorboard designed for solid and suspended ground floor applications, including solid concrete, beam and block, and suspended timber floors. Available from 25mm to 150mm, it is widely specified across both new build and retrofit projects.

K106 Cavity Wall Board

The Kooltherm K106 is a full-fill cavity wall board for masonry construction, with a water-tight, vapour-open polypropylene fleece outer facing to protect against moisture penetration and a low emissivity composite foil inner facing. Available in 90mm and 115mm.

K107 Pitched Roof Board

The Kooltherm K107 is a phenolic pitched roof board used for insulating warm roof spaces in ventilated and unventilated pitched roofs under tiles or slates. It is suitable for between-rafter and over-rafter installations, as well as attic floors, dormer windows and dwarf walls. Available from 25mm to 120mm across both new build and retrofit projects.

K108 Cavity Board

The Kooltherm K108 is a partial-fill cavity wall board for masonry cavity walls, designed to maintain a residual cavity while maximising thermal performance within the available wall build-up.

K110 Soffit Board

The Kooltherm K110 is a high-performance phenolic board used to insulate structural ceilings (soffits), including semi-exposed concrete floor decks in car parks, storage areas, loading bays and similar areas beneath habitable buildings. Available in 70mm to 100mm.

K112 Framing Board

The Kooltherm K112 is a phenolic framing board for use between studs or as insulating sheathing in timber and steel-framed wall systems. Lightweight and easy to cut, it is used across new build and refurbishment projects.

K118 Insulated Plasterboard

The Kooltherm K118 combines a phenolic insulation core with a 12.5mm tapered-edge plasterboard facing, providing insulation, drylining and vapour control in a single board. Suitable for mechanically fixed and adhesive bonded internal wall drylining applications. Available from 37.5mm to 82.5mm.

K5 External Wall Board

The Kooltherm K5 is a phenolic external wall insulation board for masonry walls, with a glass tissue facing on both sides, suitable for use behind traditional and lightweight polymer-modified render systems. Available for both new build and refurbishment applications. The Kooltherm K5 is a phenolic external wall insulation board for masonry walls, with a glass tissue facing on both sides, suitable for use behind traditional and lightweight polymer-modified render systems. Available for both new build and refurbishment applications.

Applications for Kingspan Kooltherm

Floor Insulation

Kooltherm K103 is the primary floor application board, suitable for solid concrete, beam and block, and suspended timber ground floors. Its slim profile allows high thermal performance to be achieved within constrained floor build-ups, making it a practical choice for both new build and refurbishment installations.

Wall Insulation

The Kooltherm range covers cavity wall, external wall and internal wall applications. The K106 is a full-fill masonry cavity wall board and the K108 addresses partial-fill cavity wall construction, while the K5 is used in external wall insulation systems behind polymer-modified render on masonry walls. The K118 insulated plasterboard covers internal drylining applications and the K112 framing board is used between studs or as insulating sheathing in timber and steel-framed wall systems, across both new build and refurbishment projects.

Roof Insulation

The Kooltherm K107 is designed for pitched roof insulation, suitable for between-rafter and over-rafter installations in ventilated and unventilated pitched roofs. It is used in both new build and retrofit roof upgrades, as well as attic floors, dormer windows and dwarf walls.

Soffit Insulation

The Kooltherm K110 is used for the insulation of concrete soffits and structural ceilings in applications such as car parks, storage areas and loading bays beneath habitable buildings, where a high-performance board fixed directly to the underside of a concrete deck is required.

Why Choose Insulation UK for Kingspan Kooltherm?

The Full Kooltherm Range in Stock: K103, K106, K107, K108, K110, K112, K118 and K5, all available across a wide range of thicknesses.

Premium Phenolic Insulation from Kingspan: with lambda values as low as 0.018 W/mK, Kooltherm delivers some of the highest thermal performance of any rigid insulation board available in the UK.

Fast UK-Wide Delivery: with free shipping on orders over £500 ex VAT and reliable nationwide logistics on every order.

Competitive Trade Pricing: backed by strong stock availability and a trusted supply chain across the full Kooltherm range.

Over 50 Years of Industry Experience: with more than 20,000 customers across the UK, Insulation UK is a trusted supplier for contractors and trade professionals working to tight U-value specifications and programme deadlines.