Abstract: A flexible, flame-retardant composite material includes a fabric layer; and at least one impregnated or coated Polyvinyl Butyral (PVB) coating layer, which is integral with said fabric layer. The PVB coating layer contains 20 to 60% by weight of PVB, at least one plasticizer in an amount of 5 to 40% by weight of the coating layer, and at least one flame retardant in a total amount of 5 to 75% by weight with respect to the coating layer. A manufacturing method thereof is also described, and includes an impregnation or coating of a water-based dispersion of PVB onto the fabric layer, and a further curing.