Sometimes a rolled roof cannot be constructed. Originally, the alternative was proposed in 1957 in the United States. Solutions of polymers were applied layer by layer, creating a solid coat after settling.
Specifically, a solution of polychloroprene rubber and chlorosulfonated polyethylene with fillers and vulcanizing agents are applied to roof base. In both cases, when the solvent evaporates, cold vulcanization occurs: a 1 to 1.5 mm elastic and non-porous film is created. This technology was applied from 1957 till 1963 in the USA and Canada, but was discontinued due to the toxicity of the organic solvents. Subsequently, liquid polymer compositions based on polyurethane with tar pitch were applied in the USA.
Liquid roofing materials can also be produced from chloroprene and acrylic latexes. Such solutions can be found on the roofs of skyscrapers in Chicago and New-York. In recent years, Japanese and American roofing workers began using acrylic mixes.
In the 1990s, a new latex-based composition, non-toxic and nonflammable, was developed. It protected the treated surface from moisture and retained its properties through many freezing/melting cycles.
For modification of roofing bitumens, special equipment is used, such as GlobeCore UVB-2 plants. They can produce roofing materials based on all currently known polymers in the form of either powder or granules. Plant capacity varies from 4 to 40 m3/hour, there are models for small companies and big construction concerns dealing with roofing and waterproofing.