Abstract: There is described a fire-break door comprising a swivelling leaf provided with at least one lock with draw-bolt which can be controlled by an operating member, said leaf cooperating with a door-closer allowing to swing said leaf back automatically to the closed position thereof, in which means are provided on the one hand to retain the lock bolt in a recessed or withdrawn position when the door leaf lies in closed position, and on the other hand to let the bolt be released and enter the keeper of the lock with an abnormal rise in the temperature adjacent the door.

Abstract: There is described an intumescent fire-proof element comprised of a plate having on the one side thereof rectilinear grooves allowing folding; a fire-prevention structure comprising between a skeleton and metal sheets, such an element cooperating with means directing the expansion towards a space through which the composition the element is comprised of, may escape outwards; and a method for preparing said composition by contacting a liquid alkaline metal silicate solution with a powder-like hydrophilic substance.