uword asked:
the mishnah says you have to be distance the sid from the wall. What is the diffrence between this sid and the sid thats on the wall?
uword,
The Kollel replies:
Piles of Sid, like Gefes and Zevel, generate Hevel-heat which can harm the wall, unless it is kept three Tefachim away, or unless the wall is coated with Sid, in which case it insulates the wall from the Hevel effect of the pile. The Sid also stops moisture penetrating from a wet pit. A thin cover of Sid does not itself generate Hevel.
All the best,
Reuven Weiner