Mezuza Before Hanging Door

Question: We have just completed an extension to our house, but the doors we have ordered are not due to arrive for a few weeks. Should we attach the mezuzos in the meantime?

Answer: The Gemara (Menachos 33a) records that when Rav Nachman was asked by the reish galusa to help him affix his mezuza, he instructed him to hang his door first. Rambam (Mezuza 6:1) writes that having a door is one of ten conditions for a doorway to be obligated with a mezuza. One must hang the door before affixing the mezuza (ibid. 6:5). In a letter to the Chachmei Lunil (quoted in Kesef Mishna Mezuza 6:1), Rambam explained that the Torah uses the word shaar to teach that only a doorway with a door is obligated to have a mezuza attached.

However, Raavad (Mezuza 6:1) and Tosafos (Menachos 33a) explain that Rav Nachman instructed him to hang his door simply so that he could ascertain which side the mezuza should be affixed to.

While the Shulchan Aruch (YD 286:15) quotes both opinions, he writes (Beis Yosef YD 286:15) that the halacha does not follow Rambam. The Shach (YD 286:25) writes that ideally one should affix the door first. If one is unable to do so, one should affix the mezuza without a beracha. When one hangs the door, one should remove the mezuza and reaffix it, again without reciting a beracha (see R’ Akiva Eiger YD 286:6). Alternatively, one should do so after reciting the beracha upon affixing another mezuza. The Chayei Adam (1:15:9) and Aruch Hashulchan (YD 286:24) concur with the Shach.

In conclusion, if one cannot hang the door yet, one should affix the mezuza though one cannot recite a beracha. Upon hanging the door, one should remove and reattach the mezuza.