What kind of things can invalidate an eruv?

Question

I'm just now learning about Eruvim and all their complexity. What kind of things can invalidate an Eruv, or are required for an Eruv's validity? This question is inspired by this comment,

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 [yiddish] for question)/ "getting psak" (rabinnical advice) – יהושע ק

I would just like to be more informed on this topic.

Answer 1

There is an entire tractate of the Talmud on this matter, called Tractate Eruvin. That's around 500 pages of text. Once you read through that and understand it thoroughly, you have to check the corresponding section of the Shulchan Aruch on Eruvin. You would likely want to pay particular attention to the Rema's commentary on that section if you are in the US, where most eruvim are run by Ashkenazi organizations.

Answer 2

Too complicated to go through here, but please see Rabbi Bechhofer's book: https://www.amazon.com/Contemporary-Eruv-4th-Eruvin-Metropolitan/dp/1680251325

(You're welcome to study the entire Talmudic tractate that serves as raw material, but only certain portions of it wind up being relevant to today's typical cases. Hence, try something more focused.)

Answer 3

This is a very complex topic, subject of many books. One I would highly recommend for being both deep and approachable - with many real-life examples is

Walking the Line: Hilchot Eruvin from the Sources to the Streets by Chaim Jachter.

If you have further specific questions, you are welcome to ask another question.