Someone (Bucharan) told me that his Rabbi and his Rabbi's Rabbi say that you can put a decorative tarp under the schah and it will remain kosher (even if rain cannot go through).
To me this feels wrong.
Is he correct? Sources please.
It seems it is true from here
If one places an artistic covering underneath his schach within four tefachim of the schach and his intention is to beautify the sukkah the sukkah is kosher. However, if the covering is placed above the schach or if it isn’t to beautify the sukkah, the sukkah is invalid
footnote 45 ibid
Shulchan Aruch 627:4. Chazon Ovadia p. 84 writes that if one’s intention is to both beautify the sukkah and to protect oneself from the sun and rain the sukkah is kosher.
The source that even if it blocks the rain is Chazon Ovadia on Sukkot p. 84