Gyproc Thermaline

British Gypsum Thermaline insulated plasterboard is the UK's leading dry lining insulation solution, combining a factory-bonded plasterboard face with a rigid insulation core to deliver exceptional thermal performance without sacrificing internal space. Whether you're a contractor working on a new build or a homeowner tackling a refurbishment, the Gyproc ThermaLine range offers a complete wall and ceiling insulation solution to help meet current UK Building Regulations and reduce energy bills.

The range is split into three distinct product families. Gyproc ThermaLine Basic features a CFC and HCFC-free expanded polystyrene (EPS) core bonded to a 9.5mm Gyproc wallboard, available in thicknesses from 22mm to 40mm. It's the ideal cost-effective choice where a basic level of thermal insulation is required — perfect for window reveals, solid walls, and rooms where space saving is a priority.

Gyproc ThermaLine Plus uses an extruded polystyrene (XPS) foam core bonded to a 10.5mm plasterboard, available from 27mm to 48mm thick. This mid-performance board regulates room temperature, reduces condensation, and features an integral vapour barrier — making it particularly well suited to window reveals and internal wall lining in both residential extensions and conversions.

For the highest thermal performance, Gyproc ThermaLine PIR uses a rigid polyisocyanurate (PIR) foam core with a thermal conductivity of just 0.022 W/mK, bonded to 12.5mm Gyproc WallBoard. Available in 38mm, 53mm, 63mm, 78mm, and 93mm thicknesses, it delivers superior U-value improvements with minimal loss of room space. The dual integral vapour control layers prevent condensation and protect against damp and mould. Also available in a ThermaLine PIR MR (Moisture Resistant) variant — ideal for kitchens, bathrooms, and other high-humidity environments — this board meets Euroclass B-S1, d0 fire performance standards and carries BBA certification.

All Gyproc ThermaLine boards are manufactured to BS EN 13950, available in the standard 2400mm × 1200mm sheet size with a tapered edge finish, and are compatible with the full British Gypsum Thistle plaster finishing system. They're suitable for dot-and-dab adhesive fixing or mechanical fixing direct to masonry, timber, or metal frame construction — in both refurbishment and new-build applications.

Shop the full British Gypsum Thermaline range at Insulation UK and benefit from fast UK mainland delivery, competitive trade pricing, and expert product support. Whether you need insulated plasterboard for solid walls, room-in-the-roof lining, or loft conversion insulation boards, we have the right Thermaline product in stock.