Pergola - Kosher scach?

Question

This pergola was originally put up a around 2 weeks before Sukkos 5783. The shade that this makes is at least 50/50 (if not more.)

So several questions:

1. Is this kosher scach by itself? If yes, what about now a year later, the person would have to lift up and put down every small piece of wood to be able to machshir it for this year?

2. If it's not kosher scach by itself, why? And if a person wants to put up a bamboo sheet (or anything that is yes "kosher scach") on top of it does it "make trouble" the fact that it's there (the beams that are "not kosher" -- for whatever reason.)

3. If it's kosher scach as it is and the person does not lift up every beam and puts kosher scach on top of it is it a problem?

Answer 1

1. The amount of shade is likely sufficient. The amount of shade is measured at the schach level: if the schach is more than the empty space the schach is kosher. It certainly appears from your picture that you have more schach than empty space. Even if you don't have enough schach coverage now, a few pieces of bamboo on top would provide enough total coverage. While the amount of schach is probably fine, there's another problem here, as follows.

2. It's hard to tell from your picture, but generally pergola boards are finished boards (as opposed to rough pieces of wood). Large boards (4 tefachim - approximately 36cm wide) are posul mdrabbanan even when placed on the narrow end. This is called the "gezairas tikrah", a Rabbinic psul due to the similarity with the roof of a house. The Rama says the minhag is to refrain from using finished boards that are even smaller than the four tefach shuir. See Shulchan Aruch HERE . If it's unfinished pieces of wood then this problem would not apply and your succah would be fine.

3. I don't know if it is a problem or not to put kosher schach on top of boards that provide more shade than sun on their own. This may depend on if your boards are four tefachim wide and therefore posul mdrabannan or less than that and not truly posul. (Putting kosher schach on top of pasul schach generally doesn't help.)

4. If the schach is kosher, your question about lifting them up again this year is based on the problem of "succah yeshana", an old succah. Roofing that is kosher schach but was not put up to be used for the mitzvah of succah should be refreshed for the mitzvah. The Mishna Berurah ad loc. paskens that schach that was put up to be used as a succah last year also needs to be refreshed for this year's succah. The Shulchan Aruch, ad loc. states that only a small portion of the schach needs to be lifted. Your case may be slightly worse than a regular succah yeshana since you were living in the pergola the whole year. The Mishna Berura ad loc. points out that a roof you were living under the whole year must be refreshed. This thorough article (footnote 16) has a proof from the Mishna Berura here that in such cases all the schach must be lifted up and put back down.

5. One additional point to keep in mind is that many pergolas have only a roof and no walls. Even the most kosher schach that is placed before the walls are erected is pasul because of "t'aseh vlo min ha'assuy". If this is the case, the schach must be lifted up and replaced after the walls are erected. See Rama HERE.

Nothing written here should be relied on halachically, but I think this covers the basics on your question.