Insulated wall panels with a mineral wool core are used where cladding with specific thermal, fire or acoustic properties is required. They may appear in industrial halls and public buildings. However, the suitability is not determined by the name of the core alone. The entire wall assembly, including openings and connections, is important. One of the reasons is the requirements relating to the behaviour of the wall during a fire. Panels with a mineral core can have appropriate reaction-to-fire classes and fire resistance classifications. However, the specific product and the method of installation must be checked. Not every thickness and span gives the same result.