Hi there, I'm building a 19'x19' raised paver patio, using ep henry coventry wall blocks and pavers. The wall should will be raised about 15". This is my first time doing a job like this and I had a few questions. 1. How wide does the compacted wall base need to be? I heard that the base should extend b/w 4-6" on either side. Is this necessary? 2. I'm using a less than 1" gravel blend for the base, do I need to backfill the area near the wall with clean rock? Do I need to run drainage pipes through a patio of this type? 3. Do I backfill the patio area as i build up the wall. What I mean by this is do I lay a row of bricks and then compact the patio base up to that level..adn then lay another row. Or can I build the entire wall of the patio and then fill it in with the gravel base afterwards? 4. Any other thoughts on important aspects i might be missing??? I have many more questions..but this is a start! I appreciate everyones help and input!