Use this section to specify hydraulic cement underlayment, a poured-in-place, self-leveling Portland cement-based floor underlayment.
Portland cement-based floor underlayments are self-leveling or trowellable products used for filling and leveling floors. They must be placed over a concrete or plywood structural floor; they do not provide structure on their own. They are not suitable for exterior use. They are often covered with finished flooring
Depending on the specific underlayment they may be, left exposed, polished, or dyed/stained. Consult with an underlayment manufacturer to select a product to meet your project requirements.
Learn more about self-leveling concrete, visit Wikipedia.