Expanded polystyrene or polyurethane thermal insulation board, useful for thermal insulation of e.g. wall foundations and damp exterior walls, has a coating of a specified building material, based on silicate

Polystyrene or polyurethane thermal insulation board with small holes over its surface, comprises an outer coating to improve the mechanical/physical properties of the outside surface. The outer coating comprises the building material Leton (RTM; very fine natural mineral silicates), which provides good mechanical properties and a low water vapor diffusion factor mu of 10. Polystyrene (EPS/XPS; expanded polystyrene) or polyurethane (PUR) thermal insulation board with a low water vapor diffusion factor mu of less than 10 and an outer coating to improve the mechanical and other physical properties of its outside surface, according to . The board is provided with holes of small diameter over its surface and has an outer coating of the building material Leton, which provides the required mechanical properties, e.g. high strength, especially abrasion resistance, water and frost resistance, low swelling and shrinkage. Polystyrene or polyurethane thermal insulation board with small holes over its surface, comprises an outer coating to improve the mechanical/physical properties of the outside surface. The outer coating comprises the building material Leton (RTM; very fine natural mineral silicates), which provides good mechanical properties and a low water vapor diffusion factor mu of