Too late on the sides, Huskerfan, they've been burried per specs for a week now. Our instruction manual required 12 x 12 along with crusher fines and said the round ends were optional since there is no downward pressure there, so that's what we ended up going with. Our soil is black clay that was professionally tamped. By the look and feel of it, I think we're going to be okay...maybe for only 20 years though.

Shelley