The Gemara here tells us that wood used for Sechach becomes Asur b'Hana'ah for all of Sukos.
It is popular to point out that a person can make his convertible car into a Sukah by bringing along wood and covering the hole in the roof of the car with the Sechach so that he can eat under it. But doesn't the entire Sukah become Asur b'Hana'ah? Will a car used in such a manner become Asur b'Hana'ah for the rest of Sukos?
Thank you,
Rabbi Moshe Perkal, Yerushalayim
Rabbi Perkal,
We were asked a similar question during the last Dafyomi cycle. Below is a copy of our answer.
Kesivah va'Chasimah Tovah,
Mordecai Kornfeld
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You are asking a very important and observant question.
The "Atzei Sukah" become Asur and are Muktzah for all seven days because the Etzim have been designated for use in the Sukah at the time that Yom Tov enters (i.e. Bein ha'Shemashos of the first evening of Sukos). One may not make a Tenai ("I am not exclusively designating this material for the Sukah, for I retain the ability to use it during Bein ha'Shemashos") before Yom Tov to use the Etzim later on Sukos for personal use (as one may make in order to use the Noyei Sukah), since it is not possible to use the Etzim the first day of Yom Tov during Bein ha'Shemashos, because removing them from the Sukah would involve a Melachah on Yom Tov (Mishnah Berurah OC 638:6; Beitzah 32a).
However, a Tenai may be used for a Sukah made during Chol ha'Mo'ed, such as a "car Sukah," even if it is used as a Sukah during Bein ha'Shemashos. Furthermore, it is logical to assume about something that one obviously does not intend to leave as part of the Sukah, that it is understood he is using it with a Tenai and the item does not become Asur. (The Mishnah Berurah writes a similar Sevara from the Taz, regarding fancy lace wall-coverings which one does not intend to leave hanging at night.) Only if Yom Tov (or Shabbos) comes when the material is being used as a Sukah will the material then become Asur (since it is not possible to use it during Bein ha'Shemashos because of Meleches Shabbos or Yom Tov).
The Bi'ur Halachah you referred to (OC 638, DH Asur l'Histapek) says that a Sukah decoration does not become Asur until Bein ha'Shemashos comes (and one has made no Tenai), even if it was hung up on Chol ha'Mo'ed. (This is because the decoration does not become a part of the Sukah until it is there at the beginning of a new day. It presumably should not apply to an item that actually comprises the Sukah itself, and is not just a decoration.)
As for an item that becomes Muktzah in middle of Shabbos, the Halachah is that an item does not become Muktzah for an entire Shabbos if it is becomes Muktzah in the middle of the day (Muktzah l'Chatzi Yom; SHULCHAN ARUCH 310:3).
Best wishes,
Mordecai Kornfeld