What is Celotex TB4025? The thermal board is a universal high-performance insulation that can be used for pitched roofs, flat roofs, timber frame walls, floors, room-in-the-roof applications and ceilings. It is suitable for both new build and renovations and comes in a wide range of sizes from 12mm all the way up to 200mm. With low emissivity foil facings these thermal boards are manufactured from rigid polyisocyanurate (PIR) using a blowing agent that has zero ozone depletion potential (zero ODP) and low global warming potential (GWP). The BBA-certified boards are manufactured to a high standard and are specifically designed to be light and rigid, improving transportation, handling and fitting. Due to this, they are an extremely reliable and long-term board. Benefits of Celotex TB4025: • High-performance insulation boards, reducing building & renovating costs • Environmentally friendly manufacturing process with a low climate impact • Tough, rigid yet lightweight insulation boards making installation easy • Brilliant thermal performance with thermal conductivity of 0.022 W/m.K • They are also a sustainable building choice with a BRE Green Guide Rating of A. The Celotex  TB4000  boards have been deemed a Euroclass E Reaction to Fire classification, according to BS EN 13501-1. Products with this level of classification are not provided with a rating for smoke emission. Celotex PIR boards come in three different ranges depending on the thickness. 12mm-45mm fall into the  TB4000  range, 50mm - 10mm fall into the  GA4000  range and 110mm to 200mm fall into the  XR4000  range. They are all multi-purpose insulation boards developed to provide simple solutions for overcoming localised thermal bridges.