A hydraulically binding composition can be used to produce an inorganic fire-protection and/or insulation foam. The composition includes: (i) a hydraulic binder, (ii) a blowing-agent mixture, (iii) a thermally expandable compound, and (iv) optionally a foam stabilizer, where the at least one thermally expandable compound, depending on a particle size thereof and an adjusted density of a foamed composition, is present in a quantity such that a foam structure of the foamed composition is not destroyed by expansion thereof during heating of the composition above an onset temperature thereof.