Fly ash (FA) is a by-product of coal combustion in power plants whose characteristics depend on the type of combustion process and coal properties. A large proportion of FA is used by the cement and concrete industries, but most is disposed to landfill, potentially causing environmental problems. The main objective of the CEFYR project was to study new fire-proof products (FPP) in the laboratory and at the pilot level, employing FA from a pulverized coal combustion power station and other industrial wastes and cellulosic derivatives. As a result of the project, new FPP have been developed and manufactured as panels or as sprayed surfaces. In this paper is described one such product: panels formed by simple compaction or by vacuum filtration using coal fly ash, waste paper and other industrial wastes. After thermal treatment to eliminate the cellulosic matrix and produce high porosity products, their stability at high temperatures was assessed. The results show that the developed FPP are stable and have acceptable physical and mechanical properties. In addition, the insulating capacity of the products was assessed by submitting one of the panel faces to heat according to standard fire resistance tests, and measuring the temperature rise on the cold face. The results indicate that some of the manufactured FPP have better insulating properties than other commercial fire-resistant products, and consequently, that it is possible to produce FPP using FA and other residues as raw materials, using simple, cost-effective processing methods.