Just about any floor covering can be applied on top of UFH, including
Carpet (ideally with an underlay having a combined TOG value less than 1.5)
Ceramic and Slate tiles
Vinyl
Wood
Thinner floorings will generally have a low thermal inertia, and allow a faster response time by the underfloor heating loops to changes in temperature required by, people entering or leaving rooms or to sudden changes in habitation pattens within a household such as someone visiting or coming to stay for a day or two.
These changes do not normally occur, or have already been considered at the design stage, in industrial and commercial premises and in these cases a covering with a higher thermal inertia can be considered.