May one sweep off porch on Shabbos/YT?
The general rule with sweeping on shabbos is that if the area being swept is usually paved or covered, such as inside our homes, it is permitted. However a type of area that is generally uncovered in that town, (such as a walkway in a bungalow colony, where many pathways are on the ground itself), then such a path may not be swept, as we might come to sweep the ground. A porch, even if it as outside one, without a roof, is never made of earth, therefore it would be permitted to sweep it on shabbos. You should not use a straw broom because some of it will break off while sweeping. A horsehair or synthetic broom is permitted.
O:CH 337-2, Biur Halacha ibid D:H V’yesh Machmirin, Aruch Hashulchan ibid 5, Zachor V’shamor Choresh pg. 7, Nishmas Hashabbos 3- 286, Rema O:CH 316-3, M:B 14.