Abstract: A fire resistant wall element comprises a phase conversion material, preferably glauber salt, the phase conversion of which takes place at a temperature below about 50.degree. C. and is endothermic. According to the invention, the wall element (1) includes a further, a second, phase conversion material (6) placed adjacent the firstmentioned phase conversion material (3), the phase conversion of the further phase conversion material (6) taking place at a higher temperature than the aforementioned temperature, the further phase conversion material (6) being intended to be placed nearer the outer surface (5) of the wall element (1) than the firstmentioned phase conversion material (3), this outer surface being the surface which is heated in the event of fire.According to one preferred embodiment, the further phase conversion material (6) contains bound water in such large quantities that the endothermic reaction taking place during the phase conversion process essentially constitutes the vaporization of water.

Abstract: A fire resistant wall construction incorporating a phase conversion material the phase conversion of which takes place at a temperature below the temperature at which wood, paper etc. is liable to ignite. The phase conversion material includes a mass (2) produced from a mixture of water-glass in liquid phase and water and a binder such as cement or the like, the phase conversion material having a water content of such magnitude that the endothermic reaction taking place during the phase conversion process is essentially constituted by the vaporization of the water present.