The question was asked recently in light of the icy weather that we have been having. Is it permissible on Shabbat to place rock salt on the ice in order to melt it?
So obviously the question is being asked about your porch where you are allowed to carry, or in the area in the backyard where it is permissible to carry. Is it permissible to pour rock salt on the ice to melt it on Shabbat?
The Tur in seman 313 discusses a different type of case where a person’s area where he walks was ruined by rain, and so the person wants to place some straw on the ground. The Tur says that this would not be a problem on Shabbat of building because you are not going to leave it there since animals would eventually eat it up. It’s not like you are putting water and brick to fix the floor, but rather you are just putting some straw to make it easy to walk, and you are not leaving it there because the animals would eat it up anyway, and therefore you would have no problem of fixing. He says just to sprinkle it in a non-normal fashion. If you normally sprinkle by throwing it in front of you, so sprinkle by throwing it over your shoulder. And really the Halacha is the same by pouring rock salt on snow or ice on Shabbat. The Halacha, it is permissible on Shabbat to pour rock salt.
The only problem is the Rav Beer Moshe writes, that people are under the assumption for whatever reason, that this is forbidden. They don’t know why, but it is one of those things that you would think is forbidden to do on Shabbat. Therefore he says, when you are sprinkling the rock salt, you should try to do it when no one is around. Scout the area first to make sure that no Jews are around, and then sprinkle. Because the other Jews may suspect that you are doing something that is forbidden. Or even better, let a Goy do it. If you have a Goy who is able to do, it would not be a problem for him to sprinkle the salt.
So the Halacha Lema’ase, it is permissible to put rock salt on ice on Shabbat without a problem. However, we said you should do in private where no Jews are able to see it or you could have a non-Jew do it. But only to do it in a place where you are able to carry.
