If a child got locked in a room is one permitted to break the door?

The gemora Yuma 84b says that if a child got locked behind a door one may break down the door even if it involves a biblical prohibition. The gemora says that even if one needed the splinters for firewood and is cutting the door in a manner which will thus benefit him, it is permitted. The Sha’ar Ha’tsiun 328:17 says that obviously one must break the door in the quickest method possible. He may therefore not cut the door in a manner benefiting him if it requires doing more actions.

The Aruch HaShulchan asks how the gemora can permit such a method of cutting when one can simply break down the door. He answers that it would frighten the child.

We see from here that leaving a child behind a locked door involves pikuach nefesh and everything must be done to release him from his prison. 1

A door came off its hinges into my hands, am I permitted to return it?

Although a door revolves on its hinges, in the eyes of the halacha it is static, being that it is not carried from place to place. 2 That does not mean that one is forbidden to open or shut a door, it means that if it came off it is hinges it is muktze.

Removing the door from its hinges on Shabbos is forbidden because of Soter – Dismantling, but if it did happen, then A) one is forbidden to place it on its hinges, due to the biblical prohibition of Boneh – Construction, B) the door is muktze. 3

What then, am I supposed to do with the detached door?

Since it is muktze it may not be moved from place to place and ideally it should be left exactly where it is. However, if it poses a threat because either people might trip over it or it might fall onto someone; it may be relocated elsewhere until out of harm’s way. 4

If the mechitza – screen between the men and the women fell down, is one permitted to stand it up again?

This halacha is based on a few factors. One is biblically forbidden to erect a permanent tent on Shabbos, even if he does not thrust pegs into the ground or knot rope to hold up the tent. The prohibition is based on the melacha of Boneh – Construction and tent building is included. Chazal were afraid that if one were to erect a temporary tent it would lead him to construct a permanent one, and hence instituted a g’zeira (rabbinical prohibition) forbidding the erection of even a temporary tent. 5

Tosefos, in Shabbos 125b, says that a screen or partition does not fall into this category unless it creates a halachik wall (which will soon be explained). The Mishna Berura 6 teaches us that one may erect a screen used for separating between men and women at a shiur, provided that it is temporary, otherwise it will fall into the category of Boneh.

What is the halacha with regards to setting up a screen to block out the sun?

If the erected screen is temporary and no nails/screws etc were employed to set it up, it is permitted. Blocking out the sun is not a halachik screen either.

What then, is a halachik screen?

A halachik screen creates an entity where without this partition a certain halachik requirement would be lacking. 7

For example: a kosher succah is comprised of three walls. One is forbidden to add a third wall to two existing ones, even if the third wall would be a temporary screen, because the third wall ‘creates’ a succah and without this wall the succah is not a kosher succah.