A method of manufacturing a laminated, light-transmitting fire-screening panel comprising at least one solid layer of intumescent material sandwiched between two structural plies without the use of a sheet of plastic material to effect the bonding, comprising the steps of forming a stratum from an intumescent material assembling the stratum and a first structural ply to an inorganic face of a pane comprising a second structural ply so that the stratum is in contact with the inorganic face and sandwiched between the structural plies, enveloping at least the edges of the sandwich assembly in such manner as to define a space around the edges in which sub-atmospheric pressure can be created for subjecting the inter-ply space to suction at the edges, and subjecting the sandwich assembly to a treatment in which at least one of the main external faces of the sandwich assembly is exposed to sub-atmospheric environmental pressure while the sandwich assembly is exposed to heat in a treatment chamber and the inter-ply space is subjected to the aforesaid suction to effect bonding of the various plies without causing the intumescent material to become tumid.