Coating for protecting constructions, particularly against heat and fire

Abstract

A coating for protecting constructions against fire and heat, comprises 10 to 80% by weight of aluminous and/or Portland cement and 5 to 20% by weight of hydrated trisodium phosphate (Na.sub.3 PO.sub.4.12H.sub.2 O). A small but effective amount of a flux can be included, which can be calcium borate and/or fluorspar, the amount being effective to assure superficial sintering of the refractory particles at a temperature between 850.degree. and 900.degree. C. This temperature range is selected because if sintering takes place below 850.degree. C., the cracks which form in the coating are filled too soon by fusion of the inorganic particles under the action of the flux; while if sintering takes place above 900.degree. C., the coating becomes detached from the supporting surface because the binder loses all of its adhesive power. The coating can also include inorganic particles, e.g. alumina, sand, perlite and/or vermiculite, and also organic particles.

Dependencies are inferred from the claim text.