1) THE REQUIRED THICKNESS OF THE WALL (Yerushalmi Halachah 3 Daf 2a)
עד כדון לארכו לרחבו
(a) Question: Until now we have discussed the height of the wall (that it must be four amos), what about the thickness?
א"ר נסא כותל חצר לא נעשה אלא להציל לו.
(b) R. Nasa: Since the purpose of the wall is to prevent hezek re'iyah (the damage of one neighbor peering at the other), the thickness only needs to be enough to prevent it.
סברין מימר שאם רצה לקרות אינו מקרה
(c) Question: Since no particular thickness was stated, the Chachamim suggested that even a very thin wall would therefore suffice. However, the problem is that it cannot support a roof, which is unlike the Mishnah?
א"ר יוסי בי ר' בון תיפתר על ידי מרישיו:
(d) Answer (R. Yosi bei R. Bun): Although its walls cannot support a roof, it could have strong beams that can support a roof.