9. The Sukkah floor:
Some Poskim rule that it is proper for one to build a tiled floor for the Sukkah in commemoration of the Ananei Hakavod, and in order to be allowed to sweep it on Shabbos and Yom Tov. Practically, the Chabad custom is not to be particular in this matter.
A grass floor: Initially, one should not build a Sukkah over grass, due to the possible “planting” prohibiution applicable on Shabbos and Yom Tov if one pours liquid onto the rgass. Bedieved, if one made the Sukkah over grass, then he must beware not to spill or pour water over it. Alternatively, one can place a makeshift floor over the grass. See Halacha 5E for the full details of this subject.
An earth floor: There is no issue in building a Sukkah over earth if it is hard and not designated for growing plants and grass, and is a distance of 15 Amos from any surrounding trees.
 P”M 643 M”Z 4
 Sefer Haminhagim p. 65
 See Ketzos Hashulchan 142:14; Daas Torah 336:3, brought in Piskeiy Teshuvos 336:3