What thickness can self-leveling cement be applied? What is the difference between underlayer and top-layer self-leveling cement?

Underlayer self-leveling cement is normally applied at 2–10 mm. It is mainly used for subfloor levelling, with flooring, PVC or carpet installed on top. Top-layer self-leveling cement can be applied at 2–5 mm. It forms a smooth finished surface and can serve as the final floor finish. For thickness exceeding the upper limit, multi-coat application is recommended to prevent cracking.