Q: Virtually all the doorways in our house are archways. To be more specific, their doorposts rise straight up for about a meter and then begin arching. Here’s my problem: If I put the mezuzah within the top third of the straight part of the post, it will not be within the top third of the doorway. Yet, if I put it on the top third of the doorway, it will be on the curved section, which is really the lintel!
A: This is a common conundrum, and each of the placement options you mentioned is supported by halachic authorities (and rejected by others!).
Many authorities assert that when the sides rise straight-up at least ten tefachim before arching, the area above the beginning of the arch is deemed to be the lintel, and the area below that point, the post. These authorities hold that one should never place the mezuzah anywhere on the curve, just as one may never place it on a lintel.
Accordingly, one measures the post from the floor to the start of the curve and places the mezuzah in the top third of this area.
Now, ordinarily, one must be careful to place a mezuzah at least one tefach below the lintel, which in this case would be one tefach below the beginning of the curve. However, in order to stay within the top third of the overall height (to fulfill option two, as well), it would be allowed to place the mezuzah within the top tefachim before the curve.
Other authorities rule that the mezuzah is affixed to the top third of the entire doorway, even if that would mean placing it in the curved area. (When measuring, keep in mind that the halachic “top” of the doorway is the point at which the two sides of the arch come within four tefachim of each other.)
This opinion cautions that if one places the mezuzah on the straight part of the doorpost when it is not within the top third of the entire post, he may not have fulfilled the mitzvah.
Ideally, one should consult one’s local rabbi in this matter as to local custom. If that is not feasible, one may rely on either approach, as both are halachically well-based.
- Sources: Turei Zahav Y.D. 287:2; Chovas HaDar 7: n. 35; Agur B’ohalecha 12:27; Kuntres HaMezuzah 287:17; Pischei Mezuzos 289:12