I took the to bottom two pices and cut half rounds in with chainsaw, than dry fit it and desided that the top pice wayed enough that it wouldent move. I was going to put some finish nails in the bottom put the fit was good and it didnt move so, good enough. It is 3 sprate pices all are heavey and the top should take 2 pepole. I can move it by myself but hurts.