I'm a reformist Jew. But I have a Jewish friend who is unreformed. He is living in an Eruv. They want to move to another house in the same neighborhood! They're concerned because their new house is no longer inside of the Eruv. This would create undue hardship. As a service to them since I'd be acting as an agent, I'm considering placing poles on their property and extending the Eruv myself with fishing line.

  • Do I need any external authority to extend an Eruv?
  • If I can't just extend the Eruv: can a "greater" Eruv exist as a superset? Can he just check his own Eruv extension around his new property every week before the sabbath?
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    the laws of establishing an eiruv are complicated and need an expert. Simply erecting poles will not suffice. There is, no doubt, an organization responsible for the eiruv. Contact them and they can extend parts in accordance with halacha
    – rosends
    Commented Aug 23, 2022 at 16:53
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    I don't think "need an expert" is a good answer, could you could answer the question as to what an expert needs to do so I know what I can do and what else, if anything, I have to have an expert do? Commented Aug 23, 2022 at 18:00
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    @EvanCarroll for this kind of thing you need to talk to an Orthodox rabbi- lay out the whole situation and have him explain the best/easiest/least expensive way to do this. If you take action on your own, you risk invalidating the existing eruv. An Orthodox Jew would have go through exactly the same procedure, it's called "asking a shayla" (Hebrew for question)/ "getting psak" (rabinnical advice) Commented Aug 23, 2022 at 18:30
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    Firstly, you need to confirm that there are no halachic issues within the extended area that invalidate the eruv. Things like a reshus harabbim, karfef and the like. If there aren’t any, then the extension needs to be all the way up to the existing eruv. Lastly, the one who makes the eruv has to include him in the bread/matza that combines everyone so regardless the eruv committee would need to be involved
    – Chatzkel
    Commented Aug 23, 2022 at 21:28
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    In addition to all this, the organization maintaining the eruv would have to add the extension to their regular checking/maintenance tours
    – mbloch
    Commented Aug 24, 2022 at 4:08

1 Answer 1


First of all, @Evan, it is extremely touching that you are willing to go such lengths for a friend, particularly on behalf of a friend's religious observance. This speaks a lot about who you are as a person.

That said, this really isn't something you can do on your own.

There is an external authority that runs the eruv on behalf of those living inside of it. You cannot modify an existing eruv on your own, and if you tried to, you would probably invalidate the existing eruv.

You are also unable to build a separate eruv on your own. The laws of eruvim (the plural of eruv) are extremely complicated and in our times even a knowledgeable neighborhood Orthodox rabbi will go to a specialist in these matters.

If you would like to help your friend with this, your first step would be to go see his rabbi. Call the synagogue, say you'd like to get some psak (rabinnical advice) and make an appointment.

  • 1
    Especially city-wide eiruvs. Usually the local Rabbi will present the proposed eiruv to a nationally or internationally recognized Rabbi for final approval.
    – N.T.
    Commented Aug 23, 2022 at 22:54

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