585. Closing a Chimney

In an introductory note to this chapter, the Kitzur Shulchan Aruch writes that most Jews are already familiar with the prohibited labors of Shabbos and that he is only addressing common situations with which people may not be familiar. Clearly, the laws of Shabbos constitute an area requiring much greater study than this email alone will allow. 80:79 If the pipe of a chimney extends from the side, then blocking it is considered adding to a partition, which is permitted on Shabbos. However, if it comes out the top, it may not be closed on Shabbos or yom tov because that constitutes making a tent. If there is a permanent metal hatch attached to the chimney with hinges, one may close it on Shabbos, as this is no different than a door attached with hinges.

80:80 Regarding a cloth that is spread over the opening of a barrel to cover it, if the barrel is not completely full and there remains an empty space of a handbreadth between its contents and the cloth, then the opening may not be covered in its entirety. In order to avoid the problem of making a tent on Shabbos, one must leave a small area of the opening uncovered. (As discussed in 80:33, we may not cover a barrel of water with a cloth that isn't designated for that purpose out of concern that if it falls in, one will likely come to wring it out – see Bi’ur Halacha 315:13 s.v. beged.)