Supplied as a pack of 6 sheets covering 17.28m², 50mm Kingspan Kooltherm K103 Floorboard puts a standard-depth floor's worth of phenolic insulation into a single order. The 50mm is one of the most commonly used floor thicknesses, and the six-board pack maps neatly onto a single room or a compact ground floor, where the whole area is insulated at once rather than patched in sections.

Each board measures 2400mm x 1200mm and covers 2.88m², so six boards give 17.28m² to set out across the floor. The rigid thermoset phenolic core has a thermal conductivity of 0.019 W/mK and a thermal resistance of 2.60 m²K/W at 50mm, with glass tissue facings bonded to each face during manufacture. A compressive strength of 120 kPa lets the boards sit below a screed or slab and take normal floor loads once the floor is complete.

Kooltherm K103 is a rigid board that handles easily for its performance, lighter to move and position than many floor insulants, so a full pack can be set out across a floor in a manageable number of lifts. With uniform 2.88m² boards arriving as one batch, joints butt consistently across the room and trimming is kept to the perimeter.

Across beam and dense block, suspended timber and solid concrete floors, the 50mm sits below the screed, below the slab or between the joists to suit the build. It is laid over a damp proof membrane and fitted to Kingspan's guidance and the project specification, and it is not placed directly over timber joists. The pack quantity suits domestic, commercial and industrial floors in new build and refurbishment, and runs with underfloor heating systems.

Key Benefits of Kingspan Kooltherm K103:

• Pack of 6 boards covering 17.28m², sized for a single room or compact ground floor.
• 50mm rigid thermoset phenolic floorboard, one of the most commonly used floor thicknesses.
• Thermal resistance (R-value) of 2.60 m²K/W at 50mm.
• Lambda of 0.019 W/mK, among the lowest conductivity figures in rigid floor insulation.
• 120 kPa compressive strength for screed and normal floor loads.
• Light and straightforward to handle, so a full pack lays across a floor in fewer lifts.
• Square-edge boards at 2.88m² each, faced both sides with glass tissue.
• Beam and block, suspended timber and solid concrete floors, below slab or screed.
• One batch on one delivery, keeping a floor's boards consistent across the area.
• Compatible with underfloor heating, for new build and refurbishment.

Good to know:

• Bed the pack onto a damp proof membrane of at least 1200 gauge polythene; the boards must never sit straight on subsoil.
• The board resists water vapour but does not replace a vapour control layer: where a screed follows, run a separate polythene sheet over the top with lapped, taped joints to serve as the VCL.
• In a suspended timber floor the boards seat between the joists on battens, saddle clips or nails, never fixed across the top of them.
• The pack delivers 2.60 m²K/W per board, but the finished floor's U-value comes from the full build-up, so confirm the calculation before settling on pack quantities.

Only need part of a floor, or a few boards? The 50mm is also sold as single sheets: view single sheets.

When a floor is insulated at standard depth, the six-board pack covers a typical room from a single order and a single batch.