Matital Roofing Roofing sheets Our co-extrusion system aggregates in a single sheet three layers of different materials, each of which is optimized to perform certain functions. 1. Top Layer: to obtain colors and perfect finishes that are highly UV and chemical-resistant. 2. Middle layer: to obtain low thermal expansion, bendability, and acoustics. 3. Bottom Layer: thermoplastic compounds for maximum impact strength and chemical resistance.