Bill Tindall, E.Tn.
It's always a good idea to have physical access to the mattress before you determine the dimensions of the frame
Not being able to see into the future to know the various mattresses this bed will need to accommodate I will just have to make a guess.
I do not understand this statement:
I don't see any space (5/8") for the slats between the bottom of the mattress and the top of the ledger board. What's a ledger board? Space?