Decks, Patios, Porches and Docks - block wall

what is the best method to attach a ledger board to a block wall

I assume you are talking about a ledger board for a deck. WHY attach it to the wall at all? Why not just make the deck free-standing in relationship to the wall?

THANK YOU LEFTY, I SHOULD EXPLAIN A LITTLE FURTHER, THE DECK IS SIX FEET FROM GROUND/GRADE, I AM HOPING TO MAKE IT WITH A SOLID ROOF , AS IN GOING INTO THE EXISTING ROOF.
BECAUSE OF OUR LOCAL BUILDING CODE, I HAVE TO BE SOLID, AND ATTACHED TO THE EXISTING HOUSE.

HOPING TO MAKE IT INTO A THREE SEASON ROOM, ALL CLOSED IN
THOUGHT A LEDGER BOARD WOULD BE A GOOD WAY TO GET A SOLID START, IF YOU CAN GIVE ME MORE IDEAS IT WOULD BE APPRECIATED THANKS AGAIN

MURRAY ATKINSON

Since your local bldg. dept. is requiring the deck to be attached (and rightfully so), ask them how they want you to attach it. They have to approve whatever you do anyway! Do it their way, and you only have to do it once.